Retired Alaska commercial fisherman. Spent a lot of time working on metal boats. Spray foam is the way to go. Provides a moisture barrier, prevents corrosion. No heat transfer at the ribs. Is easier than you think to remove, use razor blade and side grinder. No problem. Like the other person said, install sufficient tubes and Chanels .
Agreed, not that hard to cut out and how often might you want to do that? If you had to remove an area of foam you can keep a couple small canisters of Tiger foam spray to reapply a spray foam coating. Tiger foam comes in a couple sizes and replacement nozzles for re-use. 2 small propane cans ( one with urethane and the other with resin ). So its the same stuff you might have applied commercially. Go Delos!
Spray foam on metal hulls is the only way. If you use foam panels, you need to maintain a vapour seal. otherwise, any exposed metal will sweat. This means taping every single foam section to the next foam section, so no moisture can get behind. The glue on the aluminium tape fails in the Tropics. Any self-adhesive foam has the same problem. Glue failure. It's a nightmare. Spray foam has none of these problems and vastly minimises a risk of corrosion as no moisture can touch the aluminium hull
We are seeing tons of boats with corrosion from the separation of the foam up on the hull sheet. Spray foam has come a long way but I still don't like it.
I have an aluminium catamaran 13 years old. The spray foam is the only way. You’ve got a point. Every part of the hull that is not perfectly isolated will be a thermal bridge. I added some insulation panels over the foam to cover as well as possible. However the condensation that you can see and remove is not a big problem. You have to worry about hidden condensation. Dirty is the most dangerous reason of corrosion. Under a dirty spot and around it there is a difference of oxygenation and this is enough to start corrosion. This is typical into the water tanks. Small deposits of lime starts, under them, corrosion. Last thing. It’s correct, the spray foam may be a problem if you need to access under it. But under the foam the aluminium is like new, also after more than 13 years. Sorry for my English.
I've owned 2 steel boats with insulation. The first had fitted foam panels secured to the interior hull. My current boat has spray foam insulation. I think the spray foam is superior because there are no gaps as is inevitable with fitted foam panels. If you do need access to the inner hull a chisel will make short work of the foam and at least with a steel boat that's hardly ever necessary. The spray foam as you say is a durable tight efficient coating.
And spray foam is very tight and very sealed. I personally think it's superior. A tight air seal is much more important than people realize. You can't get that cutting phone pieces to fit. Only spray foam seals tight as a drum. So many people don't realize that having a tight air seal is extremely important to insulation. It can really add to the r value and the effective properties of insulating. Gaining access later can quickly become a moot point because of proper wire chases conduit and piping. If most of the chases have conduit and it's well thought out and planned the spay foam is not a problem for maintenance. Even so a whole saw or even a cutting knife and you can gain access to the spray foam incredibly easily.
Hi Brian... John & Candice from Shilshole... I've used a product, maybe one that you are looking at. This was 18-ish years ago. 1 product is "delta-t" for insulation and another product is "delta-db". Both are roll on or spray products. I've rolled the delta-t on bulkhead like chain lockers to cabin. I've rolled the delta-db on the genset covers to stimulate the gen noise. It might help you attenuated noise from your green set to the adjoining cabin. Were enjoying your videos too the max.. Take care.. John&Candice on "The Two 13's"
With any insulation make sure it is inflammable/ fire retardant! Also an air gap between insulation and panelling gives a lot of additional insulation.
Have you looked into Total Boat Flotation Foam - 2 Part Expanding Polyurethane Marine Pour Foam For Boat Floatation, Insulation And Soundproofing (2 LB Density, 2 Quart Kit) as a way to increase your bouncy? There are foams the put in buoy's that are water resistant and mold resistant. Just a thought when you mentioned weight.
I have a steel boat with spray foam, its great to protect the metal underneath since you have zero air gaps and its very good at preventing condensation since it cover all cracks that you will likely miss with the foam boards. Also, you will (hopefully) only need access the hull very rarely, especially where the foam is at (at and above the waterline), so going for the easier (cheaper and faster) method of spraying is likely the way to go. I did some metal work on my boat recently, took a grinder with a wire brush about 10 seconds to clear the area (good vacuum is recommended haha) and spraying it back on is easy (plus the bottles of spray can store much easier than foam board cut-outs). Hope this helps! Loving the series
mechanical engineer with experience with insulating stainless steel machines. spray foam is purpose made for this application. no thermal bridging, no thermal coatings to worry about, no air gap management, way less risk for condensation. just plan you wireways & utility pathways ahead of time and when repairs/mods pop up just get the scraper out. respraying after the work is done is easy peasy.
I am commenting here because I like this answer and while I don't know jack-poo about boats my first concern was condensation under insulation and I think this covers that concern.
Mechanical engineer here who also builds houses.. Condensation in nearly all wood applications I've seen. Several states. Can't address it everything has to be ripped out for fresh blow insulation... He needs to be able to maintain his boat and foam board is water proof... It may break apart but it doesn't collapse internally like spray foam when wet. Even closed cell will. Try actually building something then get back with I'M A MECHANICAL ENGINEER.
In aviation, we use Zinc Chromate primer on all the metal parts for anti corrosion, then we put insulation blankets in between the frames and over the ribs (just as you described). Your inside is build pretty much the same way as an airplane, and we have to deal with condensation as well (and fire proofing). My vote would be some type of anti corrosion spray on primer (something that you can also get in a spray can maybe, so that if you needed to do a repair you could re-coat the area) and then add insulation. We also use insulation tape in areas that aren't conducive to blankets. I would say in your case, look into the aerospace industry to see what the latest and greatest stuff can be bought over the counter. If you go with a primer, spray it on before you install anything else, and once you have installed your component you'll probably will have to inspect for scratches/rubs and then re-coat (usually a brush on step at that point)
this aircraft primer is the only way to go for preventing corrosion surprises. then whatever removable insulation over the top. in boats you always need access to the plates for inspection.
As a Fire Safety Engineer, i 100 % support this suggestion. Metal won't burn of course, but if a fire spreads to your insulation via conduction, you have no chance of putting it out. To add to this, if your insulation is plastics-based, it will melt and form a very, very hot pool at the bottom of your hull. This has happened in buildings many times, and the problem is that even if you manage to put out the fire, it re-ignites due to the hot pools at the bottom. I would advise that you avoid foaming plastics alltogether, even though I understand that condensation and general water proofing is priority number 1. Do not overlook fire proofing. You don't need it until you REALLY need it.
Mirage2991 I was thinking the same thing as you. Aircraft go from -40 to +90 degrees in minutes. Brian being from the Seatle area I am sure you know someone who can dig up a Boeing engineer to advise you. I think they use a combination of insulation. Some high-density to block low frequency and low-density. In housing construction, all wires and plumbing is run before they start to install insulation. All high end homes here in Montana use a combination of spray foam and batten insulation. Condensation will form on any wood that is not insulated.
Hi Brian, Think this is best suggestion option I've read, the only addition would be to perhaps use household brand ZIP tape to airtight seal gaps and joints, or what in airlines is sometimes called 1000 mph tape ie metal backed duct tape with a complementary aluminum composition to avoid corrosion issues from a Stainless Steel tape. It can seal extremely well and is still removable in a year or 3 when you WILL need to inspect at some point. Maybe if you add the second layer of foam to back of wall trim panels and use velcro with some screws for securement ? Can that foam be hot wire trimmed for cutouts or just use an electric carving knife like on conventional foams ?
I work for a lumber dry kiln manufacture. Kiln temps range up to 240F and almost continuously near 100% relative humidity. Kilns live in northern cold climates and tropics. Structures are 6061 aluminum. Walls are a sandwich construction of .040" thick 5052 aluminum skins surrounding 2.25" thick Celotex Thermax rigid foam board for r20 insulation. This is a closed cell polyurethane board that won't absorb water. Panels have weep holes. We sometimes use 304 stainless inner skins on hardwood kilns as acids can corrode aluminum. So does salt from salt water stored logs. I think you are on the right track. Use a combination of spray foam for the main areas and difficult corners and batts with the coating system where you need access. This is why I like your channel. You have interesting problems to solve and share them with your audience.
I have a buddy that is a general contractor. We just had a long conversation about insulation and air flow. From what I've found doing research and from speaking with my friend is that if there is ANY air gap between the outside and the insulation, you WILL get condensation. This will likely lead to mold, whether or not the insulation picks it up, it will still be present. Spray foam completely seals the pocket, leaving no air gaps. If you spray it on the ribs, it also prevents temperature transfer through the ribs into the boat interior. As mentioned below, run extra conduit for possible future projects.
For my steel boat refit (43ft ketch), I had to remove hundreds of bags of old, mouldy spray foam. Never again. Fitted 2” closed cell foam panels and then a 1” gap between the foam / metal and the inner liner (8 x 4 plywood sheets). The air gap allowed air to flow in the inner skin and any condensation to run into the bilge, and it was easy to remove foam for surveys or additional wiring runs. Spent four cold UK winters living aboard just fine. 14 years later, the boat is still doing fine with zero rust and no mould.
65 yr old Naval Architect, Live-Aboard and Boatbuilder specialising in metal boats. (Awesome build BTW thank you for the videos). While I almost always recommend spray foam for all the reasons covered below.. I do like your thinking on the painted surface and then cut blocks too. BUT, a mentor once said "A boat is only as good as the sum of it's compromises" So I think I'd swing back to the spray foam as there's probably fewer compromises there. WIRING If you think you need 2 wire conduits, PUT in FOUR.. IF you think you need 3" tube use 4" instead. You WILL be adding more wiring later. One of my mistakes on my current boat.. not enough room to pull new wires. LAST recommendation: Use some foam tape on top of your flanges between the interior paneling and aluminum as a thermal break. I wish I'd done that on my current one as well. I also go back and forth on VAPOR BARRIERS.. sometimes I wish I'd done that but I don't know if it would just cause other issues.. I would look at Tyvek or other one-way vapor controllers. There are some good lengthy insulation threads on Boat Design Net forums as well.
Hi, Sorry to bother you with a stupid question. Meaning that I'm not building anything, and I just ask of curiosity. Is it possible to apply the liquid vapor barrier Brian was talking about and then go in with spray foam? Would it be overkill because there is a good enough vapor barrier with the foam alone, please? Why I'm so interested in vapor barriers. There was a court case that was part or the reading when I went to law school, back in the long ago. It concluded that not having a correct vapor barrier in the house was not a hidden fault, the plaintiff didn't do his due diligence when inspecting the property (the professional building inspector or what the term is in English), and the plaintiff was turned down. That's when I decided to never buy a house. I would have read the case in 1989 or 1990, and I still haven't bought a house. If you read this far, thank you. Yours, Ann
@@annlidslot8212 THere are some spray coatings that you can apply on top of the spray foam (after the spray foam is done and trimmed). The coating gives a hard waterproof glossy finish
@@rickwelin9773 Hi, Thank you so much for your answer. I didn't really think anyone would find it worth the effort, as I'm not building anything. This surface would then be the vapor barrier, am I interpreting it right? So if mould would happen (this was the fault in the court case) it would happen between the aluminium and the spray foam? Not that I would expect mould happen these days when we know how dangerous it can be. I'm just trying to understand with my limited know how. Yours, Ann
I work with aluminium sailboats, I have a Ovni 445 insulated with XPS. Sound really travels from the water and there is more clunking from waves that I would like. The Xps does not soundproof. Also condensation gathers behind the insulation, eventually running off. It is a 2008, and we have no problems with mold and such. I have done extensive repairs and have not seen any corrosion on behind insulation. But a lot under chipped paint on deck. I also have experience with a KM yachts which is PU spray foam insulated. This seems like a much better option in terms of function. The PU bonding to the alu seems to stop the sound resonating. If you ever need to do repairs including welding on the hull above water line, which is very unlikely, it is such a big undertaking anyway, that scraping the PU foam will not be the big issue. PU foam However, it is super toxic foaming agent and gasses off for a long time. The same goes for XPS, it is not meant for inside insulation of homes, but rather foundation insulation. I would personally install a network of cable tubes for futureproofing installations, and PU foam the boat. The noise insulation and effective insulation is on a different level.
Honestly, I think you have already answered your own question. Spray in does have the one draw back but it has so many pro's that it might be easy to put up with the one big con it does have which is sorta what makes it so good. It sticks to EVERYTHING!!!!
I know nothing about insulation but I find this boat build and the way you are going about it absolutely fascinating ! Love all of your videos. Good luck with this insulation problem, looks like a lot of good advice posted.
Great video, Brian! For insulating your aluminum cat, consider a layered approach: start with a thermal coating like Mascoat DTM or PyroTech T35 for corrosion protection and basic insulation. Add closed-cell foam (like extruded polyethylene) for thermal and sound insulation-adhesive-backed or pin-mounted for flexibility. Seal edges carefully to prevent moisture buildup and consider thermal break tape on exposed metal areas to avoid condensation. For tricky corners, a bit of spray foam can help fill gaps. Modular insulation panels make future access easier. Hope this helps-excited to see how it turns out!
Brian, I’m a former contractor sales rep. I learned several things about insulation. 1. Any kind of foam board insulation you are going to need a vapor barrier. 2. Any structure that requires insulation needs to breathe, meaning that your 3 boat is going to expand and contract. That’s going to cause a situation for moisture to develop. 3. The best is a total spray foam insulation, here’s the reasons why. When using spray foam insulation it automatically expands filling any and all possible ways for moisture to develop. I’m not a pro at insulation, however when I was selling insulation to contractors in the Midwest, spray foam was the top choice due to the fact it removed oxygen from any space. And with no oxygen in the space you can’t have moisture.
I think the same, this is the best and the cheapest, easiest solution Brian! Spray it forget it. You don't need to access that area again and again. Identify necessary parts for electricity and water canals before, thats all...
As a commercial and luxury boat/ship builder and designer for 50 years. Your choice for quality is but one. Here's how you do it. Etch the metal, prime with MIL-PRF-23377K Type I, Class N Yellow Chromate-Free primer, spray foam insulation. Do this only if you want the proper job done correctly. Good luck.
I think that is the same primer airplanes use. Airplane manufacturers prime every piece of Aluminum before it riveted. Airplanes suffer from major condensation and frost issues. If they didn't prime, airplanes life expectancy would be greatly shortened due to corrosion. WWII aircraft were not primed. Why waste the money on airplane that wasn't going to last long. It means that corrosion is a big problem with WWII aircraft.
There are plenty of arm chair builders on this trying to give advice which is great, but not necessarily correct. I'm sure it will be sorted out. Brian is pretty with it.
Not sure that works for a boat that people live full time on, and maybe not the most upkeep friendly. I'd rather go with an approach that is upkeep/accessible friendly.
Personally I Don't feel aluminum is proper for live aboard sailboats. One small mistake on a reef and it's gone. And finding knowledgeable repair worldwide is a major problem.
You are doing some fantastic work! I just wanna try to help regarding the insulation. Since it’s crucial to avoid condensation on the metal you need to take every measure to avoid moisture to reach the metal on the inside of the insulation. That means that the inside if the hull needs to be absolutely air tight to hinder moisture to getting into the hull. That’s really challenging and a lot of work, which is why the spray foam is the absolute greatest option. It gets completely airtight and is done in minutes. It really is not that hard to remove either since the other option with clued foam sheets also is comparably hard to remove. Good luck! I cant wait to see the oat when it’s finished! Love you guys!! You are living my dream! ❤❤
No experience other than working on large aluminum boats, decks, storage areas etc. Anytime my work got to exposed aluminum, I was told to paint with zinc chromate before putting anything on or attached to the aluminum. No idea if it helps with condensation but pretty sure it does for corrosion. Looking pretty spiffy in that new Delos shirt and full on dungarees, almost like a landlubber! 😂
Up till last year I had a steel boat with spray foam from ‘96, foam was still in perfect condition and I had no condensation problems, it was sprayed to deep under the water line keeping the boat well insulated. Yes, if you have to do some welding you have to scratch the foam off but it is not much of a hassle and after you spray some closed cell from a can. Now I have a aluminum boat with foam panels, everywhere where the ribs are not fully covered I have condensation, even before I have condensation on the windows. I would put in some extra ducts for whatever cable you need in the future, the wood strips to bolt the interior to and spray, by far the easiest and reasonably foolproof..
Closed cell spray foam is ideal. Its a one step vapour barrier and insulation from noise and radiation. Run conduit for wire and plumbing to key areas of the boat as mentioned in another post. All closed cell foam is not created equal. Be clear as to what foam product is being used and conditions during application is also very important.
The information here and in the comments is a great example of crowd sourcing knowledge. After I see what you actually do on Delos 2.0, I think this will be one of the best examples of applied crowd sourcing.
Ive been in the insulation business for 25 years. Closed cell spray foam is the way to go. It has a high R Value. At 2 inches you will get a R15 which will leave room for running wires after. Great sound deadening. It will strengthen the structure but light. If it gets wet it just dry's.
I worked in a boatyard for many years fitting out aluminium yachts and we always used spray foam insulation. It's really easy to clean off any overspray (or remove completely if required - for access or repair) using a serrated knife or scraper etc.
Cork (spray on) insulation seems to be a good idea taken from the boat world and now making moves in the van build world ... Less of the "bad things" venting offers would be from the spray on foam type and it not only acts as a vapour barrier but your sound deadening and first stage insulation. Foam sheets then to bulk out the insulation to the rating you require.
Hey Brian! I have a suggestion for your insulation issue. Back in the 90s I used to do elaborate car stereo installations. One of the products that was really popular was a sound-deadening material called Dynamat. While it was designed primarily for sound attenuation, it does have excellent thermal transfer resistance. It's fairly thin, and has an adhesive backing, is moisture resistant, and easy to cut the shape you need. I would look into that as a possibility, as it would allow access to any wiring or equipment that might be inside.
We spray foamed, no regrets. Creating pathways for all the things is super easy. Super quiet too! In my part of the world (Montreal) it was cost efficient as well. Thanks for doing what you guys do!
Spray foam is the answer in my opinion. No risk of condesation at all - strong factor. Find the way to isolate areas you think you might need access to in thr future. Best of both world.
You hit the nail on the head with the last comments about any exposed (or even less insulated metal surfaces) conducting heat and becoming subject to condensation. An Aluminum boat is a huge radiator. Any air space can collect condensation. I really dislike spray foam for several reasons but it works really well as an insulator. Cautions about off gassing both for just the foam and especially if there is any fire or even hot surfaces.
I think the part that most people forget is thermal bridging. You need to insulate the most protruding part of the bulkhead of you will have thermal bridging. I personally would think of insulation the other way around and add it to the back of the interior wall panels. That would leave air behind for moisture to dissipate and is easily removed. It’s much easier this way to avoid thermal bridges. I would also avoid metal fasteners, they will bring in the cold. Good luck!
I just posted kinda this approach. I feel the frames and ribs are going to pose a thermal induction issue for moisture contact with the interior otherwise.
If you think “they will bring in the cold” when referring to the fasteners then you don’t understand basic physics. Cold cannot travel. Only heat can travel. Cold is the absences of molecular movement and therefore can’t move. Heat is when there is a large amount of molecular movement and therefore conducts or travels.
I worked at an aluminium superyacht builder for 5,5years as a specialist for this topic and was responsible for all their insulation, structural fire, fire safety and noise & vibration solutions. This yard makes mainly sailing yachts of 40-91m in length and is highly known for it's quality. I can give some advise if you want. I prefer to plan a teams call. In that way I can explain a lot about different options and the why's of these option. It's a bit much for in a youtube review.
Hi. Very good condensation barrier and insulation : sprayed cork. 3 to 6mm over everything as you'd do with spray-foam so there's no thermal bridging. Then you add the xpe panels to get most of the insulation. Cork will regulate interior air moisture and prevent condensation. It's also fire retardant. Easy to apply, easy to repair, waterbased glue, no toxic fumes... Good job building this cat' !👍
I understand your concerns about the spray foam if you ever have to get back in there, but you will spend far more time insulating the boat in any other matter then you will having to pull foam out at a later date to fix something. I would install wire/plumbing chases and then do spray foam to both insulate and seal/coat the aluminum. My second choice would be that black closed cell foam that you were using. I would first spray the interior with some type of coding to protect the aluminum, and then I would use a combination of the black foam and spray foam two completely insulate the cavity.
Very good point. The time and money to install versus the rare occasion to possibly have to remove a spot? And if the planning of extra conduit is done, they shouldn’t have to do anything to foam ever.
Hi Brian, I have insulated my aluminium boat with the mascoat DTM along with the XTE foam. Quiet labour intensive but Iam happy with how it’s turned out. I’m semiBrisbane based and still have all the gear to spray the mascoat if you were interested. In that option Cheers mate
Hello Brian, just building a 60' aluminium sailing boat to go to cold places and I am using 2 layers of Armaflex ( 5 cm + 3 cm ) to avoid thermal bridge. I can send photos if you want to see the result.
Have you guys thought about condensation? Because from being in Navy metal ships I can tell you that all the walls that are in contact with the water below the water line will be very cold. And you’ll mostly be in warm humid weather. So having any air in between insulation and metal wall will most likely create mold and fungi to grow. It’s a very important factor to have in mind. I’ve seen water dripping off metal ship walls from how much condensation there was.
some kind of coating is a wise choice before any insulation since as you mentioned even a small bit that's exposed bare metal with sweat. I used foam house insulation and did my best to seal all exposed metal. I used canned foam around the edges to eliminate air pockets. In Europe they are spraying cork and that seems to work well. Masecoat works well and even truck bed liner coating, the main thing as you know is isolation from opposing temperatures on exposed metal. My boat is aluminum as well and I am about sixty miles north of Seattle and a former shipyard project manager.
The in-situ foamed insulation is probably right. With the pins you're showing, I would always be worried about condensation forming between the alu and the insulation. What strikes me as interesting is that you have a 15m length at least 2m hight on both sides of each hull. That's ballpark 120m2, simplyfinging that the hull deck insulation is about the same as the fore and aft of the hulls that you won't need to insulate. If that insulation is 8cm thick, that's 10m3 of insulation, providing 10t on non floodable buoyancy. Adding in the bridgedeck floor, you're probablyy not miles from having a vessel that could be flooded and keep afloat. Given you'll get close to it, it's probably worth considering whether you want to add a bit more than you need to cover the ribs and make this emergency buoyancy an integral feature of the build.
I think the spray foam is the way to go. You might consider running empty pipes throughout the boat before you spray. this way in the future if you need to run wires for some new tech you have a channel pre installed.
HI there and thanks for asking! I've been thinking this problem as well although i'm gonna have wooden boat. But thermal things are the same and as I live here up north I might know something of the issue. First of all as you probably know is that to keep condensation out you really need to cover all the metal. Boat is a very tricky thing to insulate compared to house (I'm architect btw 😅) because the vapor barrier is on the outside. Normally in houses the vapor barrier is placed on the inside surface to avoid the warm and moist air from going into the structures and they're creating condensation and moisture damage. Then the outside of the structure will allow the moisture to dry outside. But on boats when the absolute moisture barrier is on the outside and its metal in your case, you _really_ need to keep the warm air from touching that surface. Any contact will create condensation. Bigger the temperature difference the worse the situation is. In very cold climate the condensation will be frozen. And aluminum is very good thermal conductor. And then - as you said - you need either to keep moisture out from the aluminum or keep oxygen present. I just highly doubt any kind of insulation will allow oxygen to really be there enough. All the viable insulators are some kind of plastic which more or less is vapor- and airproof. So no oxygen really can enter in all the places. And if - then will the moisture (=condensation) as well. I personally wouldn't risk that. So - in conclusion - I don't really think there's any other really viable option than spray foam. You just need to think it all through beforehand to have all the conduits etc. ready to go so that you shouldn't have any need to get under the insulation. And if there's real damage in the hull - you can probably cut and melt the insulation off and repair it with some more foam later. As I'm gonna have wooden hull the problem isn't that big but wood can rot if moisture and oxygen is present. So I've been thinking of method to prevent the form from sticking too well to be able to cut pieces off from the insulation for excamination. I have no idea if that would work at all but that way I could get good forming of the insulation against the hull. We'll see. Cheers and keep it up! :Panu
That is a very comprehensive explanation, which I agree with in principle. However, I am of the opinion that self-adhesive panels and self-adhesive insulation material for the frames and stringers also provide sufficient insulation. Domestic engineering offers a wide range. The gaps must of course be filled with foam. After more than two decades in the water, I have no problem with the aluminum hull and this setup. The only condensation points are the hatch frames. I'm always excited to see your new post! :)
Brian, thanks for reaching out for advise! I do know that fuel tanks in a boat that are supported on stringers use a closed cell foam insulation not just for cushioning but also because it's waterproof and doesn't allow moisture between the tank and the stringers. Without it, you get a form of crevasse corrosion, like what happens with chain plates. That said, I believe there are closed cell spray foam types of insulation that will not only insulate the hull AND the ribs and frames of Delos 2.0 but also keep the moisture from condensation out. Off grid off road RV's used to use aluminum frames for the siding and roof and then a type of foam board for insulation but the aluminum does transfer heat from the outside. Now, top end RV builders are using composite foam material that is also structural, eliminating the need for framing members. Garcia Yachts builds A LOT of aluminum expedition boats so they might be a good resource to call and find out how they do it, what does/doesn't work... Lastly, as someone who has been doing high latitude sailing for 30 years, you want to keep air moving inside the boat while at the dock and away from the dock. I use a small force air heater that moves the air around while producing heat and that really knocks down the condensation A friend of mine was using a radiant heater that doesn't move the air around, and asked for my ideas on how to reduce the buildup of moisture and I told him to get a small fan and run it along w/ the heater. He was swabbing his San Juan 26 out every week (he is a live aboard) but now that problem is gone! While I've not used it, here is a type of commercial grade close cell spray foam systems: foamitgreen.com/product/foam-it-green-closed-cell-spray-foam/?srsltid=AfmBOoqYPPw1hdORPdXopxhEmjatWVq3mwAJb0_Mb60AW6gIapiD_LVg
Good video ! 1) Zinc chromate primer for the Bilge & 12" up. zinc chromate is a Great primer for Paint on Aluminum. 2) Spray Foam Ftw - Min 2" is the magic number. see Refrigeration load calculation program & mess with temperatures & insulation thickness parameters For Btu correlation. 3" Spray foam insulation - Good for no condensation down to 35 degrees Fahrenheit. 4" spray foam - no condensation down to -10 degrees F. 3) Run an Extra 1" & 2" empty Conduit to any Places you think you Might want to Run wires in the Future. Leave Room in existing conduits for an additional few wires and or Run a few additional unused wires to locations. 4) Just a Fyi - All Commercial Walk-in Refrigerators & Freezers are Spray Foam & it insulates For 20 Years or more. 3" Walls - Walk-in Refrigerators. Last 40 years. 4" Walls - Walk-in Freezers. New Standards are Walk-in coolers 4" Walls.
US Navy (Ret)… the ships I sailed on used lagging (foam with a layer of fabric, held in place with buttons). The stem was directly welded to the bulkhead. Your foam and button system looks much better than what we were using… Our stems were welded to the bulkhead and were prone corrosion and breaking off. I am a fan of the spray in… call it PTSD from years of bulkhead insulation repairs.
You should contact Paul and Sheryl Shard on Distant Shores. They got their boat in the water and it seems like it ended up with a very quiet and well insulated boat. I have worked with spray foam quite a bit. It is a bit messy to remove for repairs, but it very easy to back on when the repair is done. It would be my first choices as the pros outweigh the cons.
www.youtube.com/@DistantShoresTV link of their TH-cam channel herewith: it has documented the build of their new aluminium sailing yacht, it was insulated with spray foam. Check with them on their (limited) experience thus far. The experience listed by fishermen and other aluminium boat users in other comments on their preference of spray foam is probably far more valuable... Good luck with the build.
Know nothing of insulating boats, but check out the Grenfell fire enquiry ( a tower block that caught fire in the UK ). It was clad in expanded foam panels with aluminium backing. Manufacturers like Celotex lied about their fire resistance, even manipulating the fire testing regulators. The fire was started by an electrical fault and burnt for 70 hours sadly causing loss of life. The enquiry is on TH-cam if you want to get into the details. Would imagine the spray foam has no air gaps so is a safer option.
Brian Long time fan and sailer. I also am an insulation expert with a particular focus on condensation prevention. Would love to provide my knowledge to you. Your three choices all have their use. But for cold and warm weather environments the closed cell spray foam is the best option. A 2 lb density fire resistant formula would be recommended. This would be top coated with a thin intumescent layer to enhance the fire restively. The small flanges would be subject to condensation. We perform THERM simulations and design FRP pultrusions to thermally isolate this surface but allow for attachment of the finishes with minimal loss of space. I generally work on very high humidity buildings in cold environments but the physics and analysis here are the same. Feel free to reach out and I would be very happy to share my background with this issue and more detailed recommendations or analysis. Thanks for all the videos over the years.
Many van builders use lizardskin. It's two thin layers to spray on for sound dampening and insulation that prevents condensation. It's water based, so not dangerous chemicals and easy to apply. Conventional insulation material can be added. Some people use sheep wool, which stores water and releases it again under drier condition. I don't know if that works for your boat. You are doing amazing work, I wish you all the best.
I worked in large aluminium yacht construction. The insulation specifications varied throughout the vessels depending on thermal, acoustic and fire safety requirements in each area. Common thoughout the craft though was a base coat of Mascoat. The company we used to design the insulation system was Soundown.
I have lived 3 winters in Alaska in my aluminum 74ft Dashew cutter rigged sloop. We have spray foam. Install more conduit than you think you need and take pictures before spraying foam so you can find it later. Don’t foam the bilges! Make sure to spray frames and leave nothing unsprayed or condensation w freeze or condense and drip down when boat warms. Good idea to wire and permanently install dehumidifier in place in both hulls and keep running especially when you leave boat. Plumb condensation pipe from dehumidifier into bilge. Don’t mess w sheet foam the stick will release. Alaskan fisherman spray foam fish holds and have very little corrosion unless water sits on foam. You can easily grind away foam if you need to later. Make sure let floor between hulls breathe. I am worried about your big copper buss bars. You might spray them as they will get wet as well. I would love to show you pictures of my galley setup as it is fantastic and Dashew while a jerk knows how to build boats. Download his free 700 page book on how to build boats and refer to over and over.
😅 no no, please, don't spray foam the busbars. 1. the busbars will get hot, spray foam not designed for that, dangerous 2. like MANY people commented on his screw-pieced-together-busbars vid: they will fail, bad idea to start with. Foam on top of that would make it that much more difficult to (a) inspect (d) detect (c) investigate and (d) fix when they inevitably do fail
"Dashew while a jerk knows how to build boats" 😂 I met Dashew once and know exactly what you mean! However I have ended up with a Sundeer 60 which I love...
I have no idea what the Navy is doing today, but back in the early 90’s my spaces on Yorktown were in the aluminum superstructure, and they had some green kind of primer inside the skin, with those button skewers going through what looked like fiberglass insulation, which would get wet (it was an intake space on the 03 level) and had to be ripped out and replaced pretty regularly. And yes any exposed structure radiated cold - especially above the Arctic Circle. My recommendation - yes coat the inner surface / no don’t use fiberglass insulation or anything that is not closed cell. I think you are on the right track Brian.
Hi Brian, it's been a long time since I've had to work on a boat, but I have lots of experience with vehicles and homes. You're going to have a couple of problems with insulating. The skeleton on the boat is going to act as thermal conductors, there are are gaps between the mounting tabs on the frame ribs and the outer skin of the boat. The block insulation will give you more gaps for air/moisture and reduce the efficiency of the insulation as well as create places for corrosion to start. As much as I hate the idea of spray foam, it does look lie the best product for your application. Look to see what solvent will melt the foam for easier removal later. I don't know if this will help, but I hope it does.
Hi. Great work on the 2.0 boat by the way. One consideration I would take for your insulation challenge would be to consider a constrained layer damper with insulation, at least for the first coat to the bare hull. This would do two things, protect the hull from moisture, acoustically dampen the hill and provide a modest amount of insulation (you will likely need more but I have a thought on that too. Layer 1 - constrained layer damper - alubutyl material. Many options on the internet Layer 2 - block foam like you had in your video Layer 3 - multi foil as would be used to insulate houses (I used this in my barn conversion roof space for my dorma bedroom) which would solve your problem with cold bridges for the ribs in the hull. Happy to talk you through those if you wish. Good luck
Here in the Netherlands we use spray foam. Te hull is cleaned and primed with a 2k coat. It’s easy to scrape cut the foam away and so repair that. Look at s/v distances shores how that is done. Sticky back will come of when moisture gets behind it. To avoid corrosion you need to prime the hull it does not matter what isolation you pick. Aircraft have a similar problem and they use a bee wax like material but that does not work well salty environment. In aircraft isolation lives in Mylar bags pinned to the stringers. That’s done to avoid corrosion and it’s easy access. Also the weight is minimum. But this method is not isolating very well. The spray foam method makes the hull polar proof so to say. A good worked out plan with pvc pipes can make live easy for water lines and electric cables. Those can be over-sprayed with foam. You can’t isolate the complete hull as there must be a place where water can reside or condensate up on. Meaning that your bilge must not be isolated in a whole. Somewhere the moist must be collected.
How do you inspect for cracks, which can happen with aluminium? In aircraft they go through a D check where everything is removed and the hull is inspected. Is this just not necessary for a boat?
@ that’s a very good question. If the welders are wise and able to prevent extreme tention during the welding process there will be no cracks. The aluminium used for ships is different than aircraft aluminium. Also much thicker and not chemical milled like aircraft skins now. An aircraft structure is not welded but basically pinned together. Around those multiple pin holes cracks are easily formed. If the cat Delos 2 is sailing the vibration will be on a very very lof frequency. An aircraft has a massive vibration problem all the way.
@@MonkPetite Exactly. Look at videos of Dutch yacht builders and those working on Delos and watch their set up and welding. Quality beads, correct settings and the way beads are finished to avoid pits (often the origin of cracks), will help insure the hull will not develop problems.
Good video. Removing foam insulation From Metal is very easy. 1) Use a Metal Putty knife & Plunge cut small 3" Squares for removal. 2) Grab hard foam and break away from hull. 3) Use Wire Wheel on a Drill to Clean aluminum of Foam if so desired. 4) Vacuum area to clean area.
I built my own Roberts 53, steel boat. I hired a contractor to spray in two part polyurethane foam insulation in 1997. I would not do it differently. First, I had to drill thousands of holes in the frames, then attach wood furring strips (I used spruce, glued with polyurethane glue and screwed in place). All the cabinetry attaches to these wood strips so don't skip this step. Now, 27 years later - the coated steel is like new, I am sure because I have had to drill holes from time to time.
@@SVJoana Brian, you may also need wooden stringers for attaching the inner shell, although in some areas you might be able to attach to the frame riders. I attached stringers to the frame riders and it works well allowing a little room for that wire you forgot to run.
Don't get caught in the esthetics of spray. It is very manageable with proper placement of conduit and runs. Also you may leave some lockers or lazarette bare as examples of construction.
I have no expertise on this, but just a note: check if you need a fire retardant / "intumescent coating" sprayed on top of spray foam. Also, conduit seems smart but I'm not sure what's suitable for marine use. In a house I would usually use "smurf tube" / ENT tubing, but it's probably not marine rated. Did a quick search and there are interesting marine rated products in the ABB PMA Conduit Guide PDF. Love your channel, best of luck on your build!
You should do both - insulate and sound proof. It seems foam insulation will provide 100% coverage and if you have enough conduits, it should minimise any work required in the future. Have you thought of the possibility of using both materials for different sides of the boat depending of where water has more chances to penetrate?
Now I'm not a professional boat builder, but I'll be starting a 50-foot sailboat build in the next 12 months. From all the research I've done, I'm going with versi-foam system 15. Is is uscg approved as a floatation device and provides r 6.5 per inch of insulation. It is completely waterproof, and it will stick to just about anything. To make things easy, I will be using 2 inch schedule 80 pvc pipe as my electrical conduit to make make any repairs easy. I'll be using t peices with screw on caps to make inspections and access easy.
Spray foam, run pipe chases joining every compartment you can think of. You should have a ways from front to back on both sides and across to each hull with extra pipes to the kitchen and nav station. Don’t just limit it to 1 pipe you may in the future need to run different things like power or water. This boat is looking amazing.
BS Chemist here. Agree with zinc chromate for corrosion control, HOWEVER that is a "hexavalent" chromium ion, very bad news as soldiers in the Mideast Wars discovered, q.v. I'd look for some other coating. See Wikipedia page for zinc chromate: Recent studies have shown that not only is zinc chromate highly toxic, it is also a carcinogen because it contains Cr(VI). Exposure to zinc chromate can cause tissue ulceration and cancer. A study published in the British Journal of Industrial Medicine showed a significant correlation between the use of zinc chromate and lead chromate in factories and the number of cases in lung cancer experienced by the workers. Because of its toxicity the use of zinc chromate has greatly diminished in recent years.
I have experience with aluminum 18 wheeler boxes. They all get spray foamed but the plumbing and electrical runs get done first. You don't want to have to channel out all of those runs after it is spray foamed. Put in extra empty electrical runs in because it makes adding and subtracting tech wires alot easier.
Hi, here in the UK we have many thousands of canal boats floating around the country mainly steel but some aluminium. I built one myself about 10 years ago. Most, if not all are spray foamed the main disadvantage you highlighted can be overcome as you can remove it with many tools but the quickest I found for larger areas is a wire brush on a drill or grinder although a bit messy it is quick and accurate. It can be sculpted with a router, or hand tools. It would eliminate several of the problems the condensation one sounding the alarm for me. As a guide it took three hours to coat a 60 foot by 6’.10” by 6’ high canal boat. About the same amount of time to sculpt it ready for lining out. Before spray foam canal boats did use fiberglass wool and polystyrene blocks and condensation was an issue.
You might want to get ahold of US Coast Guard, they may have some great insight on what to use. Also check with your insurer and make sure any decision you make will not make the boat uninsurable. Many homes in the US now are finding out that some companies will not insure homes using a spray foam insulation. Food for thought. The boat looks great!
I was going to mention the insurance companies denying coverage as well, some folks I personally know in Colorado and another couple in Florida are fighting with it right now.
Not only the type but how it was done as well. All the cases I have seen on this it was because they hired a shady company to upgrade the insulation in an older house which was not designed for it thus it can cause problems. Go take a gander at the Build show channel here on youtube they have a few video's on it and the problems of adding foam to an existing older house. It can be done but you essentially have to do some extra steps to ensure things don't go wrong down the line. New build no issue as the house was designed for it. d
I'm an HVAC engineer. I agree with the spray foam group. Make sure to put in plenty of extra conduits. Also, I can't agree more with your comment on covering up the structural webbing! Even the vertical ones that you will be attaching your interior panels to. I consulted on a metal frame building where they spray foamed between the vertical supports but had nothing covering the supports inside or out. They attached metal siding inside and out. They had massive amounts of condensation inside on those vertical supports because of that. I would suggest radiant insulation bubble sheets or some type of thin insulation over every vertical webbing. Another thing to consider with spray foam insulation is that as long as you get a good bond to the aluminum, it will add extra rigidity to your boats hull. So definitely go with the spray foam!
The big caveat here is the spray foam need to bond to the aluminum. You saw how bonding to aluminum is not easy when you painted Maggie. You probably should etch the aluminum first the clean and apply a bonding primer if you decide to go the spray foam route.
Mechanical engineer + teacher at a technical high school here. If air from inside the hull can get through or into your insulation, you definitely will have condensation and it would surprise me if there weren't any downsides to that (like mold or corrosion). There are two ways to combat this problem: 1) Spray foam: Sticky mess, but in my opinion the ONLY sure way to completely eliminate the problem, because even if the foam were to crack, the problem would be VERY localized (no undercreeping to the sides on the foam/metal interface and thus creating a large affected area). 2) Make everything removable and create a truly airtight seal on the inside of the insulation layer with a plastic barrier film. If you have a problen then, it would not be as localized, but easyer to repair. Maybe a combination of the two would work: Put sprayfoam in (2/3rds of total insulation thickness), don't lay any cable runs into that layer. Then put removable insulation on top of that, any cable runs should go into that removable layer for ease of access and to prevent condensation inside the pipes. Even if spray foam is a no-go for you (and I totally get it), I would suggest to at least stick the foam to the aluminium at all large surfaces so there is no air gap behind the foam for most of the insulated area.
Can you find any reason not to embed conduits within a full depth of spray foam and then incorporate access ports that could be used to alter plumbing or electrical etc. in the future? Obviously if there's damage to the hull the whole thing needs to be cut out and repaired regardless and as such a provision made for any less significant repair within the structure would alleviate the downsides of using spray foam throughout wouldn't you agree?
Hey Brian I Don't know Much about aluminum but as someone who lives in a steel school bus (And has been studying the ins and outs of the lifestyle for a little more than a decade) I would recommend doing the thermal coat to prevent corrosion and then using spray foam for insulation, my advice is to run conduits through key points in the frame before applying the foam and installing access points that can be used for later maintenance for wiring, plumbing, things like that. I plan to do largely the same with my bus, Although I don't plan on encountering nearly as much salt water so I will hardly need the corrosion resistance If everything goes to plan..... and let's be Honest if I do I probably have bigger problems XD . Hope you folks have a wonderful week god bless you XP
K-Flex ECO is a great option. It's a halogen-free, closed-cell elastomeric foam insulation that's designed specifically for marine and shipbuilding. Non-Halogenated: Complies with U.S. Environmental Department standards. Temperature Range: Can withstand temperatures up to 250°F (300°F intermittent). Environmental Safety: Free of CFCs, HFCs, HCFCs, PBDEs, formaldehyde, and fibers. Antimicrobial: Contains an EPA-registered antimicrobial agent to protect against mold, fungal, and bacterial growth. Moisture Resistance: Resists moisture vapor intrusion, making it suitable for various marine applications. ABS (American Bureau of Shipping) approved for use on ships. I am a chief engineer in the USMM, I have seen the USCG come abord and inspect are ship and found USCG noncompliant (not green colored foam insulation installed and made us remove it), if you are considering using your vessel commercially. Love your show keep up the good work.
I have no idea about warmer climates but if it's cold then spray foam is superior. We've been on boats that have had it all, spray foam, mineral wool, flexible closed cell foam panels, rigid foam panels, spray cork... The requirement that we placed when we were looking for our current boat was that it had to have spray foam insulation. Spray foam is not about the ease of application but providing a proper moisture barrier. Spray foam might scare if you are not used to it, but it is easy to remove small sections of it if you for some reason need access to the hull. But how often do you need that? The hull will not secretly rot away behind the insulation (and with time you'll learn to trust that). Anything else, including the closed cell foam panels (especially if not glued on), will leave enough space for moisture and condensation to form between the hull and the insulation. Trying to leave an "air gap" between the hull and insulation is desperate, it will not help keep things dry. I just want to repeat this; if you have insulation that is NOT directly stuck on the metal then you will have moisture there. Insulation needs to be applied in such a way that it is airtight. Spray foam naturally forms a barrier like that. Pushing foam panels onto the "insulation pins" you showed won't do that and you will have condensation behind there. If you use foam panels (glued on) you will need to try and create a vapour seal, this is possible in a house but really hard to accomplish in a boat.. If you do go with flexible closed cell foam panels, I would recommend gluing them on and not using "sticky back" panels, unless you are completely sure about the quality of the sticky back, because the glue on those seems to be not as good as if you were using a separately applied glue. See for example K-flex/Armaflex, who provide sticky back panels but also sell normal panels and a special glue to go with them; we've found that using the separate glue is more reliable in the long run. It'll also be a bit cheaper and not that much more time consuming to install. Sticky backs hold first but later on can come undone. Even with spray foam you will probably have some aluminum ribs exposed. You'll quickly learn that those transfer heat and form condensation like crazy. A bit of moisture won't hurt though, it's aluminum! One option that you could also explore would be a thin layer of spray cork. This would be applied before the spray foam possibly only onto the ribs which won't have foam. This won't insulate much but will help a great deal in preventing condensation. If you want to talk about insulation and cold weather stuff, get in contact with me ;)
The spray on is how we did it but you want to have any of the electrical and plumbing done and use a pipe or tunnel to keep the space of the lines so in the future u can run new items through the same space . We used a 3 inch duct to accommodate that so the inside wall is smooth or convenient to push or pull lines without having to open the wall space
With just the options you mentioned in the video, I’d go with the spray on membrane, then the foam. Then with the, I assume removable panels you cover the walls with, I’d attach a self adhesive sound absorber. Like what’s attached to panels and floors in cars.
There’s many options and thicknesses, some are like butyl-ish type material, some are like foam gasket type material, some are covered in foil like for engine bays and what not. I just feel like the sheets of sound absorbing material on the back side of the paneling used to cover up the walls will be very multipurpose and easily maintained. Reduce noise, reduce vibration, reduce moisture wicking, easily replaceable.
There’s many options and thicknesses, some are like butyl-ish type material, some are like foam gasket type material, some are covered in foil like for engine bays and what not. I just feel like the sheets of sound absorbing material on the back side of the paneling used to cover up the walls will be very multipurpose and easily maintained. Reduce noise, reduce vibration, reduce moisture wicking, easily replaceable.
Hey Brian... another +1 for spray foam here. We are a general contractor and sprayfoam prevents thermal bridging which reduces condensation risk. In addition you wont have corrosion, or have to worry about mold. While I'm not in a boar we build homes in some of the coldest environments and have seen what happens to a house when condensation and moisture build up. Have a de humidifier installed for good measure but otherwise spray foam it
For insulation pins, I've had one of those go into my hand, when I leaned where I should not have. Perhaps, recycled plastic insulation pins / anchors might be less prone to injuries?
Thanks for letting me actually see you, shake hands and walk around your magnificent boat coming to life. Thanks Brian for being the authentic way you are and not sending me off. Do you get many unannounced visotors like me. I did not want to hold you up - so I didn't ask too much - thanks! Visiting meant a lot to me. Here are some thoughts I'd like to throw out there - for whatever it is worth. I believe thermal insulation and sound proofing/muffling tasks have separate philosophies. The dew point is the temperature where water vapor in the air turns into water. Your boat will most likely always be sailing "at sea level" so higher altitudes do not play a role for you like in avionics. But maybe you can get some ideas there. Airplanes need to stay light weight while reducing noise and keeping the inside warm for passengers. One measure could be to prevent the humid air from accessing the location where it would condensate. For sound proofing I think the task is 1. to prevent the hull from conducting/transmitting sound throughout the hull or resonating like the corpus of a guitar and 2. not let sound from outside of the hull pass through to the inside. One extreme to sound-proof, would be to fill the inside with something like dry sand. Sound waves would agitate the grains of sand which would absorb and muffle the sound. There exist self stick asphalt mats that can absorb some of the vibration. They are installed in some cars to prevent the thin steel of the outer hull from vibrating - but they also smell bad. Maybe you can get some answers from air and spaceship manufacturers. Cheers and more good luck on all your endeavors! And Y'all stay healthy, happy and the way you are!
Have you considered zinc chromate? US military uses it on it’s aluminum aircraft to prevent moisture and corrosion ,, it’s also used on ocean oil tankers , I know there are dozens of applications for it ,,
G’day Brian my name is Glenn Dawes I’m out of Fremantle Western Australia my history is refrigerating fishing vessels. I would suggest from my experience to tar apoxi seal the aluminium first so as to isolate the hull from any electrical or chemical reaction then spray foam polyurethane 2” minimum. As you know, aluminium is a brilliant conductor, so try to cover as much of metal as possible. I find this is the best long-term treatment and have had good results over many years from installations. Cheers Glyn
my last aluminium boat was insulated original with some kind off hard foam that was fireproof I have noe idea what product it was. I added more insulation with the armacell with tape on the backside and its a really really demanding job and almost impossible to get a good result. I have had boats with armacell and rockwool before and they are okay. but iff I could choose I would have gone for the spray solution to avoid cold bridges. I live in 67 degree north in Norway so you know the climate. I have been in same situation and no doubt about the spray on solution. how many times would it happen that you need to go behind the walls and do something. ? and I hope that you are planning to weld brackets over the deck where all your bolt on gear is so you don't need to bolt tru the deck
I worked in a small datacenter that was built in two phases. First phase used bat insulation resting on top of the ceiling tiles, the second sprayed insulation on the bottom of the roof. Later that year when it snowed the snow on the spray on roof lasted two days longer than the bat roof, which melted first day. By the time the snow arrived phase 2 had about 80% of the load of phase 1.
As a steel boat owner who has lived through a boat fire i don't recommend foam, carpet or any petrochemical based stuff. I do also wonder about what off gassing foam does. I used woolbatt insulation in the head lining as it's easy to remove/ replace when you want to inspect or run another wire etc. i have cork tiles on the walls, doubles as a corkboard for pictures. Will be obvious if water ingresses so will be able to arrest the issue early. It also gives a great natural feel. You may wish to consider how you would finish the interior of the boat, cork may be more expensive but may mean you don't have to line the interior. You can take advantage of the area inbetween the stringers like a "bookshelf" to have loads of storage without having to do the deep dark pit of top down storage. Have my boat just up north in Hervey bay if you interested in checking it out.
Closed cell spray foam is what you want to use. Waterproof and creates great barrier to prevent oxidation. Run conduit to any places for suspect future upgrades to get wire there and you’ll be golden
Spray foam is the absolute best option for your application. Plan ahead for your wire runs and plumbing. Run pvc rigging tubes anywhere you think you might need access in the future then spray the heck out if it. You won’t regret it
Run tubes that are far bigger than you think you will ever need & use radius bends in them, run a minimum of three 1 low voltage 1 high voltage and 1 for pex piping water.
Brian, you're getting advice from everyone with good intentions. Considering the goals of preventing condensation, insulting the boat, fire resistant material, noise reduction, and potential problems of future repair or replacement - I would set aside the concern of how hard it might be to repair structure. :¬) Webhead USA
Spray in insulation is going to be the best bet. but if you really hate it, you can use a coating then insulate like you were describing. for any exposed ribs you can use a foam tape to cover it something like permawrap works great on the yachts we service.
Cork rots when wet, like most other natural materials. In former times it was used to insulate fishing boat cold storages, but infused with tar to keep it from rotting. Not so nice on a modern boat. In boats and RVs, there really is no way around moisture-blocking foams.
@bimodo1472 it can Moist but for a vast majority of area it's decent. I get your point, but there a quite a few expedition sailboat insulated with projected Cork or Cork pannels. Personnaly i prefer to change a pannel every One and then than insulate with a very inflammable material. But i guess that's down to preference
Apply 10-20mm of closed-cell spray foam and then use the insulation batts to achieve the desired R-value. My experience is with houses, but a two-material approach might get the performance and flexibility you desire. Good luck and thanks for taking us along on the journey.
Spray foam 💯 percent!!!!! If you’re worried about any repairs , either way you’ll have to somehow remove a section of the insulation to make a repair.. the good thing about the spray foam is you can keep a case of cans of spray foam for repairs… Don’t overthink this one
Hi I made and lived on a aluminum boat in Norway. Here the weather changes from +25 Celsius in the summer to -25 Celsius in the winter. So insulation is essential for comfort. My best tip is to allow moisture and water to drain in between your hull and the insulation. It means you have a good bilge pump system to keep pumping the water out. But in my experience it’s the best way to build an insulated aluminum boat. You don’t want to stick anything to the hull. Because all of that insulation is highly flammable. So if you need to weld anything on your hull. It’s going to be a problem. I ended up using same type of insulation as the black pads you showed. But much thinner. To make the cavity between the hull and the inner insulation. Since it doesn’t absorb water and is rigid. On the inside, i used rockwool (an insulation normally used for bathrooms in houses, to prevent mold).
I think you'd be wise to survey contemporary builders of aluminum watercraft. In fact, if I were doing what you are doing, with money and lives at stake, I'd seek out an expert from one of these firms and pay him a consulting fee to answer these and other questions. Rather than guessing and soliciting lay advice, I'd strongly recommend paying for true, demonstrable expertise. Expensive, no doubt, but far cheaper than living (or dying) with regret.
Steel boat owner. We have panel insulation, with additional insulation over the ribs. *any* exposed metal will get condensation, its a fact of life because we breathe! We solved condensation using airflow through the boat, which works really well. Would I go spray foam? Yes, simply because of the time it takes to cut all the panels, fix them down (we used clips on the ribs) then tape everything, then find all the bits you missed, spray foam is much much faster. You have exactly the same issues with wire runs, as they are often under neatly taped and double insulated panels. The solution there is to run them in bundles on top of the insulation rather than under it. Repairs are actually easier with spray foam, the panels always get destroyed when you remove them, you will never get the same panel again to replace it, but cans of spray foam are easy to find and store.
You should send your question to Boeing. They have to insulate aluminum aircraft and the worry of condensation is far more critical. I'm sure they would be able to provide you with some great ideas.
Boing still has some of the best technical people in the industry - their management, QA, and sales people on the other hand are a different matter, they seem to go out of their way to put fatal flaws into what would have been good work. Getting in touch with one of the good technical people might be very difficult. However, some of these people actually publish peer reviewed technical articles. As an engineering nerd I can say this. Somewhat there is a nerd sitting in a development lab who love a chance to speak to another human.
Hi Brian …. A fan since a long time. First time writing to you. Working in the plumping business as a foreman in the heating industry, pipe fitting etc…(sorry my french). My laid pipes are sometimes insulated with a great mildew resistant material called «Armaflex». Black-in colour , but paintable, this material feels like a very firm and form adapting foam. This material is pretty dense even though being very good insulation…. Often used for possible condensation risks… In my industry it is glued on structure to be insulated AND together with a specific glue. Very good cushioned feeling very good for accident under the waves. This material is amazing. You must touch a piece of it before making your mind. Im mike from Montreal canada.
Retired Alaska commercial fisherman. Spent a lot of time working on metal boats. Spray foam is the way to go. Provides a moisture barrier, prevents corrosion. No heat transfer at the ribs.
Is easier than you think to remove, use razor blade and side grinder. No problem. Like the other person said, install sufficient tubes and Chanels .
Agreed, not that hard to cut out and how often might you want to do that? If you had to remove an area of foam you can keep a couple small canisters of Tiger foam spray to reapply a spray foam coating. Tiger foam comes in a couple sizes and replacement nozzles for re-use. 2 small propane cans ( one with urethane and the other with resin ). So its the same stuff you might have applied commercially. Go Delos!
☝️ What he said!
Seems like you could make any systems you might really need to touch accessible outside of the foam to prevent the difficulties of removal.
Spray foam on metal hulls is the only way. If you use foam panels, you need to maintain a vapour seal. otherwise, any exposed metal will sweat. This means taping every single foam section to the next foam section, so no moisture can get behind. The glue on the aluminium tape fails in the Tropics. Any self-adhesive foam has the same problem. Glue failure. It's a nightmare. Spray foam has none of these problems and vastly minimises a risk of corrosion as no moisture can touch the aluminium hull
We are seeing tons of boats with corrosion from the separation of the foam up on the hull sheet. Spray foam has come a long way but I still don't like it.
I have an aluminium catamaran 13 years old. The spray foam is the only way. You’ve got a point. Every part of the hull that is not perfectly isolated will be a thermal bridge. I added some insulation panels over the foam to cover as well as possible. However the condensation that you can see and remove is not a big problem. You have to worry about hidden condensation. Dirty is the most dangerous reason of corrosion. Under a dirty spot and around it there is a difference of oxygenation and this is enough to start corrosion. This is typical into the water tanks. Small deposits of lime starts, under them, corrosion. Last thing. It’s correct, the spray foam may be a problem if you need to access under it. But under the foam the aluminium is like new, also after more than 13 years. Sorry for my English.
I've owned 2 steel boats with insulation. The first had fitted foam panels secured to the interior hull. My current boat has spray foam insulation. I think the spray foam is superior because there are no gaps as is inevitable with fitted foam panels. If you do need access to the inner hull a chisel will make short work of the foam and at least with a steel boat that's hardly ever necessary. The spray foam as you say is a durable tight efficient coating.
And spray foam is very tight and very sealed. I personally think it's superior. A tight air seal is much more important than people realize. You can't get that cutting phone pieces to fit. Only spray foam seals tight as a drum. So many people don't realize that having a tight air seal is extremely important to insulation. It can really add to the r value and the effective properties of insulating.
Gaining access later can quickly become a moot point because of proper wire chases conduit and piping. If most of the chases have conduit and it's well thought out and planned the spay foam is not a problem for maintenance. Even so a whole saw or even a cutting knife and you can gain access to the spray foam incredibly easily.
Hi Brian... John & Candice from Shilshole... I've used a product, maybe one that you are looking at. This was 18-ish years ago. 1 product is "delta-t" for insulation and another product is "delta-db". Both are roll on or spray products. I've rolled the delta-t on bulkhead like chain lockers to cabin. I've rolled the delta-db on the genset covers to stimulate the gen noise. It might help you attenuated noise from your green set to the adjoining cabin. Were enjoying your videos too the max..
Take care.. John&Candice on "The Two 13's"
With any insulation make sure it is inflammable/ fire retardant! Also an air gap between insulation and panelling gives a lot of additional insulation.
Have you looked into Total Boat Flotation Foam - 2 Part Expanding Polyurethane Marine Pour Foam For Boat Floatation, Insulation And Soundproofing (2 LB Density, 2 Quart Kit) as a way to increase your bouncy? There are foams the put in buoy's that are water resistant and mold resistant. Just a thought when you mentioned weight.
I have a steel boat with spray foam, its great to protect the metal underneath since you have zero air gaps and its very good at preventing condensation since it cover all cracks that you will likely miss with the foam boards.
Also, you will (hopefully) only need access the hull very rarely, especially where the foam is at (at and above the waterline), so going for the easier (cheaper and faster) method of spraying is likely the way to go. I did some metal work on my boat recently, took a grinder with a wire brush about 10 seconds to clear the area (good vacuum is recommended haha) and spraying it back on is easy (plus the bottles of spray can store much easier than foam board cut-outs). Hope this helps! Loving the series
mechanical engineer with experience with insulating stainless steel machines. spray foam is purpose made for this application. no thermal bridging, no thermal coatings to worry about, no air gap management, way less risk for condensation. just plan you wireways & utility pathways ahead of time and when repairs/mods pop up just get the scraper out. respraying after the work is done is easy peasy.
I am commenting here because I like this answer and while I don't know jack-poo about boats my first concern was condensation under insulation and I think this covers that concern.
Extra conduits never hurt anyone.🤷♂️
What about the health risks of spray foam? Is there a safe, safer, safest option?
Mechanical engineer here who also builds houses..
Condensation in nearly all wood applications I've seen. Several states. Can't address it everything has to be ripped out for fresh blow insulation...
He needs to be able to maintain his boat and foam board is water proof... It may break apart but it doesn't collapse internally like spray foam when wet. Even closed cell will.
Try actually building something then get back with I'M A MECHANICAL ENGINEER.
In aviation, we use Zinc Chromate primer on all the metal parts for anti corrosion, then we put insulation blankets in between the frames and over the ribs (just as you described). Your inside is build pretty much the same way as an airplane, and we have to deal with condensation as well (and fire proofing). My vote would be some type of anti corrosion spray on primer (something that you can also get in a spray can maybe, so that if you needed to do a repair you could re-coat the area) and then add insulation. We also use insulation tape in areas that aren't conducive to blankets. I would say in your case, look into the aerospace industry to see what the latest and greatest stuff can be bought over the counter. If you go with a primer, spray it on before you install anything else, and once you have installed your component you'll probably will have to inspect for scratches/rubs and then re-coat (usually a brush on step at that point)
this aircraft primer is the only way to go for preventing corrosion surprises. then whatever removable insulation over the top. in boats you always need access to the plates for inspection.
As a Fire Safety Engineer, i 100 % support this suggestion. Metal won't burn of course, but if a fire spreads to your insulation via conduction, you have no chance of putting it out. To add to this, if your insulation is plastics-based, it will melt and form a very, very hot pool at the bottom of your hull. This has happened in buildings many times, and the problem is that even if you manage to put out the fire, it re-ignites due to the hot pools at the bottom.
I would advise that you avoid foaming plastics alltogether, even though I understand that condensation and general water proofing is priority number 1.
Do not overlook fire proofing. You don't need it until you REALLY need it.
Mirage2991 I was thinking the same thing as you. Aircraft go from -40 to +90 degrees in minutes. Brian being from the Seatle area I am sure you know someone who can dig up a Boeing engineer to advise you. I think they use a combination of insulation. Some high-density to block low frequency and low-density. In housing construction, all wires and plumbing is run before they start to install insulation. All high end homes here in Montana use a combination of spray foam and batten insulation. Condensation will form on any wood that is not insulated.
Licensed A&P here. I fully support this comment and its information.
Hi Brian, Think this is best suggestion option I've read, the only addition would be to perhaps use household brand ZIP tape to airtight seal gaps and joints, or what in airlines is sometimes called 1000 mph tape ie metal backed duct tape with a complementary aluminum composition to avoid corrosion issues from a Stainless Steel tape. It can seal extremely well and is still removable in a year or 3 when you WILL need to inspect at some point. Maybe if you add the second layer of foam to back of wall trim panels and use velcro with some screws for securement ? Can that foam be hot wire trimmed for cutouts or just use an electric carving knife like on conventional foams ?
I work for a lumber dry kiln manufacture. Kiln temps range up to 240F and almost continuously near 100% relative humidity. Kilns live in northern cold climates and tropics. Structures are 6061 aluminum. Walls are a sandwich construction of .040" thick 5052 aluminum skins surrounding 2.25" thick Celotex Thermax rigid foam board for r20 insulation. This is a closed cell polyurethane board that won't absorb water. Panels have weep holes. We sometimes use 304 stainless inner skins on hardwood kilns as acids can corrode aluminum. So does salt from salt water stored logs.
I think you are on the right track. Use a combination of spray foam for the main areas and difficult corners and batts with the coating system where you need access. This is why I like your channel. You have interesting problems to solve and share them with your audience.
I have a buddy that is a general contractor. We just had a long conversation about insulation and air flow. From what I've found doing research and from speaking with my friend is that if there is ANY air gap between the outside and the insulation, you WILL get condensation. This will likely lead to mold, whether or not the insulation picks it up, it will still be present. Spray foam completely seals the pocket, leaving no air gaps. If you spray it on the ribs, it also prevents temperature transfer through the ribs into the boat interior. As mentioned below, run extra conduit for possible future projects.
For my steel boat refit (43ft ketch), I had to remove hundreds of bags of old, mouldy spray foam. Never again. Fitted 2” closed cell foam panels and then a 1” gap between the foam / metal and the inner liner (8 x 4 plywood sheets). The air gap allowed air to flow in the inner skin and any condensation to run into the bilge, and it was easy to remove foam for surveys or additional wiring runs. Spent four cold UK winters living aboard just fine. 14 years later, the boat is still doing fine with zero rust and no mould.
65 yr old Naval Architect, Live-Aboard and Boatbuilder specialising in metal boats. (Awesome build BTW thank you for the videos). While I almost always recommend spray foam for all the reasons covered below.. I do like your thinking on the painted surface and then cut blocks too. BUT, a mentor once said "A boat is only as good as the sum of it's compromises" So I think I'd swing back to the spray foam as there's probably fewer compromises there. WIRING If you think you need 2 wire conduits, PUT in FOUR.. IF you think you need 3" tube use 4" instead. You WILL be adding more wiring later. One of my mistakes on my current boat.. not enough room to pull new wires. LAST recommendation: Use some foam tape on top of your flanges between the interior paneling and aluminum as a thermal break. I wish I'd done that on my current one as well. I also go back and forth on VAPOR BARRIERS.. sometimes I wish I'd done that but I don't know if it would just cause other issues.. I would look at Tyvek or other one-way vapor controllers. There are some good lengthy insulation threads on Boat Design Net forums as well.
Hi, Sorry to bother you with a stupid question. Meaning that I'm not building anything, and I just ask of curiosity. Is it possible to apply the liquid vapor barrier Brian was talking about and then go in with spray foam? Would it be overkill because there is a good enough vapor barrier with the foam alone, please?
Why I'm so interested in vapor barriers. There was a court case that was part or the reading when I went to law school, back in the long ago. It concluded that not having a correct vapor barrier in the house was not a hidden fault, the plaintiff didn't do his due diligence when inspecting the property (the professional building inspector or what the term is in English), and the plaintiff was turned down. That's when I decided to never buy a house. I would have read the case in 1989 or 1990, and I still haven't bought a house. If you read this far, thank you. Yours, Ann
@@annlidslot8212 THere are some spray coatings that you can apply on top of the spray foam (after the spray foam is done and trimmed). The coating gives a hard waterproof glossy finish
@@rickwelin9773 Hi, Thank you so much for your answer. I didn't really think anyone would find it worth the effort, as I'm not building anything. This surface would then be the vapor barrier, am I interpreting it right? So if mould would happen (this was the fault in the court case) it would happen between the aluminium and the spray foam? Not that I would expect mould happen these days when we know how dangerous it can be. I'm just trying to understand with my limited know how. Yours, Ann
No vapor barriers. You never want to trap moisture between 2 barriers (the skin of the boat being one)
I work with aluminium sailboats, I have a Ovni 445 insulated with XPS. Sound really travels from the water and there is more clunking from waves that I would like. The Xps does not soundproof. Also condensation gathers behind the insulation, eventually running off. It is a 2008, and we have no problems with mold and such. I have done extensive repairs and have not seen any corrosion on behind insulation. But a lot under chipped paint on deck. I also have experience with a KM yachts which is PU spray foam insulated. This seems like a much better option in terms of function. The PU bonding to the alu seems to stop the sound resonating. If you ever need to do repairs including welding on the hull above water line, which is very unlikely, it is such a big undertaking anyway, that scraping the PU foam will not be the big issue. PU foam However, it is super toxic foaming agent and gasses off for a long time. The same goes for XPS, it is not meant for inside insulation of homes, but rather foundation insulation. I would personally install a network of cable tubes for futureproofing installations, and PU foam the boat. The noise insulation and effective insulation is on a different level.
forgot to mention, remove the PU foam from every nook and cranny, DRY ICE BLASTING! no sweat
Honestly, I think you have already answered your own question. Spray in does have the one draw back but it has so many pro's that it might be easy to put up with the one big con it does have which is sorta what makes it so good. It sticks to EVERYTHING!!!!
I know nothing about insulation but I find this boat build and the way you are going about it absolutely fascinating ! Love all of your videos. Good luck with this insulation problem, looks like a lot of good advice posted.
Great video, Brian! For insulating your aluminum cat, consider a layered approach: start with a thermal coating like Mascoat DTM or PyroTech T35 for corrosion protection and basic insulation. Add closed-cell foam (like extruded polyethylene) for thermal and sound insulation-adhesive-backed or pin-mounted for flexibility. Seal edges carefully to prevent moisture buildup and consider thermal break tape on exposed metal areas to avoid condensation. For tricky corners, a bit of spray foam can help fill gaps. Modular insulation panels make future access easier. Hope this helps-excited to see how it turns out!
Brian, I’m a former contractor sales rep. I learned several things about insulation. 1. Any kind of foam board insulation you are going to need a vapor barrier. 2. Any structure that requires insulation needs to breathe, meaning that your 3 boat is going to expand and contract. That’s going to cause a situation for moisture to develop. 3. The best is a total spray foam insulation, here’s the reasons why. When using spray foam insulation it automatically expands filling any and all possible ways for moisture to develop. I’m not a pro at insulation, however when I was selling insulation to contractors in the Midwest, spray foam was the top choice due to the fact it removed oxygen from any space. And with no oxygen in the space you can’t have moisture.
Spray lanolin oil on and wipe with rag on the ally before you put the foam panels you will be fine
I think the same, this is the best and the cheapest, easiest solution Brian! Spray it forget it. You don't need to access that area again and again. Identify necessary parts for electricity and water canals before, thats all...
As a commercial and luxury boat/ship builder and designer for 50 years. Your choice for quality is but one.
Here's how you do it.
Etch the metal, prime with MIL-PRF-23377K Type I, Class N Yellow Chromate-Free primer, spray foam insulation. Do this only if you want the proper job done correctly.
Good luck.
I think that is the same primer airplanes use. Airplane manufacturers prime every piece of Aluminum before it riveted. Airplanes suffer from major condensation and frost issues. If they didn't prime, airplanes life expectancy would be greatly shortened due to corrosion. WWII aircraft were not primed. Why waste the money on airplane that wasn't going to last long. It means that corrosion is a big problem with WWII aircraft.
You bet it is. That is why it is the very best for long-term corrosion protection.
There are plenty of arm chair builders on this trying to give advice which is great, but not necessarily correct. I'm sure it will be sorted out. Brian is pretty with it.
Not sure that works for a boat that people live full time on, and maybe not the most upkeep friendly. I'd rather go with an approach that is upkeep/accessible friendly.
Personally I Don't feel aluminum is proper for live aboard sailboats. One small mistake on a reef and it's gone. And finding knowledgeable repair worldwide is a major problem.
You are doing some fantastic work! I just wanna try to help regarding the insulation. Since it’s crucial to avoid condensation on the metal you need to take every measure to avoid moisture to reach the metal on the inside of the insulation. That means that the inside if the hull needs to be absolutely air tight to hinder moisture to getting into the hull. That’s really challenging and a lot of work, which is why the spray foam is the absolute greatest option. It gets completely airtight and is done in minutes. It really is not that hard to remove either since the other option with clued foam sheets also is comparably hard to remove.
Good luck! I cant wait to see the oat when it’s finished! Love you guys!! You are living my dream! ❤❤
No experience other than working on large aluminum boats, decks, storage areas etc. Anytime my work got to exposed aluminum, I was told to paint with zinc chromate before putting anything on or attached to the aluminum. No idea if it helps with condensation but pretty sure it does for corrosion. Looking pretty spiffy in that new Delos shirt and full on dungarees, almost like a landlubber! 😂
Up till last year I had a steel boat with spray foam from ‘96, foam was still in perfect condition and I had no condensation problems, it was sprayed to deep under the water line keeping the boat well insulated. Yes, if you have to do some welding you have to scratch the foam off but it is not much of a hassle and after you spray some closed cell from a can. Now I have a aluminum boat with foam panels, everywhere where the ribs are not fully covered I have condensation, even before I have condensation on the windows. I would put in some extra ducts for whatever cable you need in the future, the wood strips to bolt the interior to and spray, by far the easiest and reasonably foolproof..
Closed cell spray foam is ideal. Its a one step vapour barrier and insulation from noise and radiation.
Run conduit for wire and plumbing to key areas of the boat as mentioned in another post. All closed cell foam is not created equal. Be clear as to what foam product is being used and conditions during application is also very important.
The information here and in the comments is a great example of crowd sourcing knowledge. After I see what you actually do on Delos 2.0, I think this will be one of the best examples of applied crowd sourcing.
Dont forget to look at flammability of the insulation. As a retired fire protection engineer I would have a look at the NFPA guidelines,
Good to note that many flame retardant additives are toxic.
amen! AMEN!
You only need a fire protective layer if the spray foam is left exposed. It's easy to install but cost $100 per gallon.
Ive been in the insulation business for 25 years. Closed cell spray foam is the way to go. It has a high R Value. At 2 inches you will get a R15 which will leave room for running wires after. Great sound deadening. It will strengthen the structure but light. If it gets wet it just dry's.
I worked in a boatyard for many years fitting out aluminium yachts and we always used spray foam insulation. It's really easy to clean off any overspray (or remove completely if required - for access or repair) using a serrated knife or scraper etc.
Cork (spray on) insulation seems to be a good idea taken from the boat world and now making moves in the van build world ... Less of the "bad things" venting offers would be from the spray on foam type and it not only acts as a vapour barrier but your sound deadening and first stage insulation. Foam sheets then to bulk out the insulation to the rating you require.
Hey Brian! I have a suggestion for your insulation issue. Back in the 90s I used to do elaborate car stereo installations. One of the products that was really popular was a sound-deadening material called Dynamat. While it was designed primarily for sound attenuation, it does have excellent thermal transfer resistance. It's fairly thin, and has an adhesive backing, is moisture resistant, and easy to cut the shape you need. I would look into that as a possibility, as it would allow access to any wiring or equipment that might be inside.
Ingenious idea to survey your knowledgable viewers.
We spray foamed, no regrets. Creating pathways for all the things is super easy. Super quiet too! In my part of the world (Montreal) it was cost efficient as well.
Thanks for doing what you guys do!
Spray foam is the answer in my opinion. No risk of condesation at all - strong factor. Find the way to isolate areas you think you might need access to in thr future. Best of both world.
You hit the nail on the head with the last comments about any exposed (or even less insulated metal surfaces) conducting heat and becoming subject to condensation. An Aluminum boat is a huge radiator. Any air space can collect condensation. I really dislike spray foam for several reasons but it works really well as an insulator. Cautions about off gassing both for just the foam and especially if there is any fire or even hot surfaces.
I think the part that most people forget is thermal bridging. You need to insulate the most protruding part of the bulkhead of you will have thermal bridging. I personally would think of insulation the other way around and add it to the back of the interior wall panels. That would leave air behind for moisture to dissipate and is easily removed. It’s much easier this way to avoid thermal bridges. I would also avoid metal fasteners, they will bring in the cold. Good luck!
This guy insulates.
I just posted kinda this approach. I feel the frames and ribs are going to pose a thermal induction issue for moisture contact with the interior otherwise.
If you think “they will bring in the cold” when referring to the fasteners then you don’t understand basic physics. Cold cannot travel. Only heat can travel. Cold is the absences of molecular movement and therefore can’t move. Heat is when there is a large amount of molecular movement and therefore conducts or travels.
@@TH-camr-k2p yeah cold can't travel...stick your tongue on a frozen pole and you aren't going anywhere!! Lol
@@TH-camr-k2p I refrigeration Hot moves to cold, I believe that is what you are saying here.
I worked at an aluminium superyacht builder for 5,5years as a specialist for this topic and was responsible for all their insulation, structural fire, fire safety and noise & vibration solutions. This yard makes mainly sailing yachts of 40-91m in length and is highly known for it's quality. I can give some advise if you want. I prefer to plan a teams call. In that way I can explain a lot about different options and the why's of these option. It's a bit much for in a youtube review.
You can always cut away the spray foam for maintenance when needed - then fill it back in after with patch can.
Beat me to it 👏
Hi.
Very good condensation barrier and insulation : sprayed cork.
3 to 6mm over everything as you'd do with spray-foam so there's no thermal bridging.
Then you add the xpe panels to get most of the insulation.
Cork will regulate interior air moisture and prevent condensation.
It's also fire retardant.
Easy to apply, easy to repair, waterbased glue, no toxic fumes...
Good job building this cat' !👍
I understand your concerns about the spray foam if you ever have to get back in there, but you will spend far more time insulating the boat in any other matter then you will having to pull foam out at a later date to fix something. I would install wire/plumbing chases and then do spray foam to both insulate and seal/coat the aluminum. My second choice would be that black closed cell foam that you were using. I would first spray the interior with some type of coding to protect the aluminum, and then I would use a combination of the black foam and spray foam two completely insulate the cavity.
Very good point.
The time and money to install versus the rare occasion to possibly have to remove a spot?
And if the planning of extra conduit is done, they shouldn’t have to do anything to foam ever.
Hi Brian, I have insulated my aluminium boat with the mascoat DTM along with the XTE foam. Quiet labour intensive but Iam happy with how it’s turned out.
I’m semiBrisbane based and still have all the gear to spray the mascoat if you were interested. In that option
Cheers mate
Hello Brian, just building a 60' aluminium sailing boat to go to cold places and I am using 2 layers of Armaflex ( 5 cm + 3 cm ) to avoid thermal bridge. I can send photos if you want to see the result.
Are you documenting your build as well?
@@mattpotts5268 It is a huge work to build that boat so no time to take video. You can see the design on TH-cam looking for ISMERIA 59'
Do ya have a youtube channel
Have you guys thought about condensation?
Because from being in Navy metal ships I can tell you that all the walls that are in contact with the water below the water line will be very cold. And you’ll mostly be in warm humid weather. So having any air in between insulation and metal wall will most likely create mold and fungi to grow. It’s a very important factor to have in mind. I’ve seen water dripping off metal ship walls from how much condensation there was.
some kind of coating is a wise choice before any insulation since as you mentioned even a small bit that's exposed bare metal with sweat. I used foam house insulation and did my best to seal all exposed metal. I used canned foam around the edges to eliminate air pockets. In Europe they are spraying cork and that seems to work well. Masecoat works well and even truck bed liner coating, the main thing as you know is isolation from opposing temperatures on exposed metal. My boat is aluminum as well and I am about sixty miles north of Seattle and a former shipyard project manager.
The in-situ foamed insulation is probably right. With the pins you're showing, I would always be worried about condensation forming between the alu and the insulation.
What strikes me as interesting is that you have a 15m length at least 2m hight on both sides of each hull. That's ballpark 120m2, simplyfinging that the hull deck insulation is about the same as the fore and aft of the hulls that you won't need to insulate. If that insulation is 8cm thick, that's 10m3 of insulation, providing 10t on non floodable buoyancy. Adding in the bridgedeck floor, you're probablyy not miles from having a vessel that could be flooded and keep afloat. Given you'll get close to it, it's probably worth considering whether you want to add a bit more than you need to cover the ribs and make this emergency buoyancy an integral feature of the build.
I'd lean towards a close cell marine spray foam and run a few empty conduits through the hull for future use if you need them.
I think the spray foam is the way to go. You might consider running empty pipes throughout the boat before you spray. this way in the future if you need to run wires for some new tech you have a channel pre installed.
HI there and thanks for asking!
I've been thinking this problem as well although i'm gonna have wooden boat. But thermal things are the same and as I live here up north I might know something of the issue.
First of all as you probably know is that to keep condensation out you really need to cover all the metal. Boat is a very tricky thing to insulate compared to house (I'm architect btw 😅) because the vapor barrier is on the outside. Normally in houses the vapor barrier is placed on the inside surface to avoid the warm and moist air from going into the structures and they're creating condensation and moisture damage. Then the outside of the structure will allow the moisture to dry outside.
But on boats when the absolute moisture barrier is on the outside and its metal in your case, you _really_ need to keep the warm air from touching that surface. Any contact will create condensation. Bigger the temperature difference the worse the situation is. In very cold climate the condensation will be frozen. And aluminum is very good thermal conductor.
And then - as you said - you need either to keep moisture out from the aluminum or keep oxygen present. I just highly doubt any kind of insulation will allow oxygen to really be there enough. All the viable insulators are some kind of plastic which more or less is vapor- and airproof. So no oxygen really can enter in all the places. And if - then will the moisture (=condensation) as well. I personally wouldn't risk that.
So - in conclusion - I don't really think there's any other really viable option than spray foam. You just need to think it all through beforehand to have all the conduits etc. ready to go so that you shouldn't have any need to get under the insulation. And if there's real damage in the hull - you can probably cut and melt the insulation off and repair it with some more foam later.
As I'm gonna have wooden hull the problem isn't that big but wood can rot if moisture and oxygen is present. So I've been thinking of method to prevent the form from sticking too well to be able to cut pieces off from the insulation for excamination. I have no idea if that would work at all but that way I could get good forming of the insulation against the hull. We'll see.
Cheers and keep it up!
:Panu
That is a very comprehensive explanation, which I agree with in principle. However, I am of the opinion that self-adhesive panels and self-adhesive insulation material for the frames and stringers also provide sufficient insulation. Domestic engineering offers a wide range. The gaps must of course be filled with foam.
After more than two decades in the water, I have no problem with the aluminum hull and this setup. The only condensation points are the hatch frames. I'm always excited to see your new post! :)
Brian, thanks for reaching out for advise!
I do know that fuel tanks in a boat that are supported on stringers use a closed cell foam insulation not just for cushioning but also because it's waterproof and doesn't allow moisture between the tank and the stringers. Without it, you get a form of crevasse corrosion, like what happens with chain plates.
That said, I believe there are closed cell spray foam types of insulation that will not only insulate the hull AND the ribs and frames of Delos 2.0 but also keep the moisture from condensation out. Off grid off road RV's used to use aluminum frames for the siding and roof and then a type of foam board for insulation but the aluminum does transfer heat from the outside. Now, top end RV builders are using composite foam material that is also structural, eliminating the need for framing members.
Garcia Yachts builds A LOT of aluminum expedition boats so they might be a good resource to call and find out how they do it, what does/doesn't work...
Lastly, as someone who has been doing high latitude sailing for 30 years, you want to keep air moving inside the boat while at the dock and away from the dock. I use a small force air heater that moves the air around while producing heat and that really knocks down the condensation A friend of mine was using a radiant heater that doesn't move the air around, and asked for my ideas on how to reduce the buildup of moisture and I told him to get a small fan and run it along w/ the heater. He was swabbing his San Juan 26 out every week (he is a live aboard) but now that problem is gone!
While I've not used it, here is a type of commercial grade close cell spray foam systems:
foamitgreen.com/product/foam-it-green-closed-cell-spray-foam/?srsltid=AfmBOoqYPPw1hdORPdXopxhEmjatWVq3mwAJb0_Mb60AW6gIapiD_LVg
Good video !
1) Zinc chromate primer for the Bilge & 12" up. zinc chromate is a Great primer for Paint on Aluminum.
2) Spray Foam Ftw - Min 2" is the magic number. see Refrigeration load calculation program & mess with temperatures & insulation thickness parameters For Btu correlation.
3" Spray foam insulation - Good for no condensation down to 35 degrees Fahrenheit.
4" spray foam - no condensation down to -10 degrees F.
3) Run an Extra 1" & 2" empty Conduit to any Places you think you Might want to Run wires in the Future.
Leave Room in existing conduits for an additional few wires and or Run a few additional unused wires to locations.
4) Just a Fyi - All Commercial Walk-in Refrigerators & Freezers are Spray Foam & it insulates For 20 Years or more.
3" Walls - Walk-in Refrigerators. Last 40 years.
4" Walls - Walk-in Freezers.
New Standards are Walk-in coolers 4" Walls.
US Navy (Ret)… the ships I sailed on used lagging (foam with a layer of fabric, held in place with buttons). The stem was directly welded to the bulkhead.
Your foam and button system looks much better than what we were using… Our stems were welded to the bulkhead and were prone corrosion and breaking off.
I am a fan of the spray in… call it PTSD from years of bulkhead insulation repairs.
You should contact Paul and Sheryl Shard on Distant Shores. They got their boat in the water and it seems like it ended up with a very quiet and well insulated boat. I have worked with spray foam quite a bit. It is a bit messy to remove for repairs, but it very easy to back on when the repair is done. It would be my first choices as the pros outweigh the cons.
www.youtube.com/@DistantShoresTV
link of their TH-cam channel herewith: it has documented the build of their new aluminium sailing yacht, it was insulated with spray foam.
Check with them on their (limited) experience thus far.
The experience listed by fishermen and other aluminium boat users in other comments on their preference of spray foam is probably far more valuable...
Good luck with the build.
They are _K M Yacht_ customers - So talk to K M not their customer!
Which part of Brian showing Distant Shores TV 0:46 on the screen with their hull being sprayed did you miss?
@@jorritschreuder9253did you miss what was shown at 0:46 ?
Know nothing of insulating boats, but check out the Grenfell fire enquiry ( a tower block that caught fire in the UK ). It was clad in expanded foam panels with aluminium backing. Manufacturers like Celotex lied about their fire resistance, even manipulating the fire testing regulators. The fire was started by an electrical fault and burnt for 70 hours sadly causing loss of life. The enquiry is on TH-cam if you want to get into the details. Would imagine the spray foam has no air gaps so is a safer option.
Brian
Long time fan and sailer. I also am an insulation expert with a particular focus on condensation prevention. Would love to provide my knowledge to you.
Your three choices all have their use. But for cold and warm weather environments the closed cell spray foam is the best option. A 2 lb density fire resistant formula would be recommended. This would be top coated with a thin intumescent layer to enhance the fire restively.
The small flanges would be subject to condensation. We perform THERM simulations and design FRP pultrusions to thermally isolate this surface but allow for attachment of the finishes with minimal loss of space. I generally work on very high humidity buildings in cold environments but the physics and analysis here are the same.
Feel free to reach out and I would be very happy to share my background with this issue and more detailed recommendations or analysis.
Thanks for all the videos over the years.
This is good advice
This is excellent advice, especially using a fire resistant formula. I am a retired general contractor. This guy sounds like he knows his stuff.
What this guy said.
Many van builders use lizardskin. It's two thin layers to spray on for sound dampening and insulation that prevents condensation. It's water based, so not dangerous chemicals and easy to apply. Conventional insulation material can be added. Some people use sheep wool, which stores water and releases it again under drier condition. I don't know if that works for your boat. You are doing amazing work, I wish you all the best.
Spray cork insulation is what odd life crafting did to their van. Might be an option for a boat.
Agree
I worked in large aluminium yacht construction. The insulation specifications varied throughout the vessels depending on thermal, acoustic and fire safety requirements in each area. Common thoughout the craft though was a base coat of Mascoat.
The company we used to design the insulation system was Soundown.
I have lived 3 winters in Alaska in my aluminum 74ft Dashew cutter rigged sloop. We have spray foam. Install more conduit than you think you need and take pictures before spraying foam so you can find it later. Don’t foam the bilges! Make sure to spray frames and leave nothing unsprayed or condensation w freeze or condense and drip down when boat warms. Good idea to wire and permanently install dehumidifier in place in both hulls and keep running especially when you leave boat. Plumb condensation pipe from dehumidifier into bilge. Don’t mess w sheet foam the stick will release. Alaskan fisherman spray foam fish holds and have very little corrosion unless water sits on foam. You can easily grind away foam if you need to later. Make sure let floor between hulls breathe. I am worried about your big copper buss bars. You might spray them as they will get wet as well. I would love to show you pictures of my galley setup as it is fantastic and Dashew while a jerk knows how to build boats. Download his free 700 page book on how to build boats and refer to over and over.
I'd use closed cell spray foam to glue the panels in to save money on the spray foam. Be sure to moisten all surfaces so the foam adhears.
😅 no no, please, don't spray foam the busbars.
1. the busbars will get hot, spray foam not designed for that, dangerous
2. like MANY people commented on his screw-pieced-together-busbars vid: they will fail, bad idea to start with. Foam on top of that would make it that much more difficult to (a) inspect (d) detect (c) investigate and (d) fix when they inevitably do fail
You've got the right idea my friend
@@raphofthehills4405 I mean yeah no foam on bus bar for sure but bus bar should be corrosion proof likewiseXP
"Dashew while a jerk knows how to build boats" 😂 I met Dashew once and know exactly what you mean! However I have ended up with a Sundeer 60 which I love...
I have no idea what the Navy is doing today, but back in the early 90’s my spaces on Yorktown were in the aluminum superstructure, and they had some green kind of primer inside the skin, with those button skewers going through what looked like fiberglass insulation, which would get wet (it was an intake space on the 03 level) and had to be ripped out and replaced pretty regularly. And yes any exposed structure radiated cold - especially above the Arctic Circle.
My recommendation - yes coat the inner surface / no don’t use fiberglass insulation or anything that is not closed cell. I think you are on the right track Brian.
Hi Brian, it's been a long time since I've had to work on a boat, but I have lots of experience with vehicles and homes. You're going to have a couple of problems with insulating. The skeleton on the boat is going to act as thermal conductors, there are are gaps between the mounting tabs on the frame ribs and the outer skin of the boat. The block insulation will give you more gaps for air/moisture and reduce the efficiency of the insulation as well as create places for corrosion to start. As much as I hate the idea of spray foam, it does look lie the best product for your application. Look to see what solvent will melt the foam for easier removal later. I don't know if this will help, but I hope it does.
Hi. Great work on the 2.0 boat by the way.
One consideration I would take for your insulation challenge would be to consider a constrained layer damper with insulation, at least for the first coat to the bare hull. This would do two things, protect the hull from moisture, acoustically dampen the hill and provide a modest amount of insulation (you will likely need more but I have a thought on that too.
Layer 1 - constrained layer damper - alubutyl material. Many options on the internet
Layer 2 - block foam like you had in your video
Layer 3 - multi foil as would be used to insulate houses (I used this in my barn conversion roof space for my dorma bedroom) which would solve your problem with cold bridges for the ribs in the hull.
Happy to talk you through those if you wish.
Good luck
Here in the Netherlands we use spray foam. Te hull is cleaned and primed with a 2k coat.
It’s easy to scrape cut the foam away and so repair that.
Look at s/v distances shores how that is done.
Sticky back will come of when moisture gets behind it.
To avoid corrosion you need to prime the hull it does not matter what isolation you pick.
Aircraft have a similar problem and they use a bee wax like material but that does not work well salty environment.
In aircraft isolation lives in Mylar bags pinned to the stringers. That’s done to avoid corrosion and it’s easy access.
Also the weight is minimum.
But this method is not isolating very well.
The spray foam method makes the hull polar proof so to say.
A good worked out plan with pvc pipes can make live easy for water lines and electric cables. Those can be over-sprayed with foam.
You can’t isolate the complete hull as there must be a place where water can reside or condensate up on.
Meaning that your bilge must not be isolated in a whole. Somewhere the moist must be collected.
How do you inspect for cracks, which can happen with aluminium? In aircraft they go through a D check where everything is removed and the hull is inspected. Is this just not necessary for a boat?
This. Spray foam over correctly primed aluminum. If damaged, foam is easy enough to remove for repairs.
@ that’s a very good question. If the welders are wise and able to prevent extreme tention during the welding process there will be no cracks. The aluminium used for ships is different than aircraft aluminium. Also much thicker and not chemical milled like aircraft skins now. An aircraft structure is not welded but basically pinned together.
Around those multiple pin holes cracks are easily formed.
If the cat Delos 2 is sailing the vibration will be on a very very lof frequency. An aircraft has a massive vibration problem all the way.
@@Cmoredebris absolutely true 👍🏻
@@MonkPetite Exactly. Look at videos of Dutch yacht builders and those working on Delos and watch their set up and welding. Quality beads, correct settings and the way beads are finished to avoid pits (often the origin of cracks), will help insure the hull will not develop problems.
Good video. Removing foam insulation From Metal is very easy.
1) Use a Metal Putty knife & Plunge cut small 3" Squares for removal.
2) Grab hard foam and break away from hull.
3) Use Wire Wheel on a Drill to Clean aluminum of Foam if so desired.
4) Vacuum area to clean area.
I built my own Roberts 53, steel boat. I hired a contractor to spray in two part polyurethane foam insulation in 1997. I would not do it differently. First, I had to drill thousands of holes in the frames, then attach wood furring strips (I used spruce, glued with polyurethane glue and screwed in place). All the cabinetry attaches to these wood strips so don't skip this step. Now, 27 years later - the coated steel is like new, I am sure because I have had to drill holes from time to time.
@@SVJoana Brian, you may also need wooden stringers for attaching the inner shell, although in some areas you might be able to attach to the frame riders.
I attached stringers to the frame riders and it works well allowing a little room for that wire you forgot to run.
Hi Wade! Just to confirm that Joana is indeed a beautiful yacht having been aboard in both Grenada and Brisbane. I would trust anything Wade says :)
Don't get caught in the esthetics of spray. It is very manageable with proper placement of conduit and runs.
Also you may leave some lockers or lazarette bare as examples of construction.
@@johnduckworth564 That is very kind John. We have great memories of our times together!
I have no expertise on this, but just a note: check if you need a fire retardant / "intumescent coating" sprayed on top of spray foam. Also, conduit seems smart but I'm not sure what's suitable for marine use. In a house I would usually use "smurf tube" / ENT tubing, but it's probably not marine rated. Did a quick search and there are interesting marine rated products in the ABB PMA Conduit Guide PDF. Love your channel, best of luck on your build!
If you choose to go with foam boards and pins, be sure that pins are aluminium to avoid galvanic corrosion.
You should do both - insulate and sound proof. It seems foam insulation will provide 100% coverage and if you have enough conduits, it should minimise any work required in the future. Have you thought of the possibility of using both materials for different sides of the boat depending of where water has more chances to penetrate?
Combination of both types of insulation. Spray foam areas with no mechanical or electrical runs, fitted foam for the remained.
Now I'm not a professional boat builder, but I'll be starting a 50-foot sailboat build in the next 12 months. From all the research I've done, I'm going with versi-foam system 15. Is is uscg approved as a floatation device and provides r 6.5 per inch of insulation. It is completely waterproof, and it will stick to just about anything. To make things easy, I will be using 2 inch schedule 80 pvc pipe as my electrical conduit to make make any repairs easy. I'll be using t peices with screw on caps to make inspections and access easy.
ANYTHING ELSE OTHER THAN CLOSED CELL SPRAY FOAM IS A COMPROMISE, THATS THE TRUTH...love the build journey
So true
Why are you yelling? Brian already said he was not keen on it as doing a welding repair on the hull in a remote location would be difficult.
@@TH-camr-k2p settle down
Spray foam, run pipe chases joining every compartment you can think of. You should have a ways from front to back on both sides and across to each hull with extra pipes to the kitchen and nav station. Don’t just limit it to 1 pipe you may in the future need to run different things like power or water. This boat is looking amazing.
BS Chemist here. Agree with zinc chromate for corrosion control, HOWEVER that is a "hexavalent" chromium ion, very bad news as soldiers in the Mideast Wars discovered, q.v. I'd look for some other coating. See Wikipedia page for zinc chromate: Recent studies have shown that not only is zinc chromate highly toxic, it is also a carcinogen because it contains Cr(VI). Exposure to zinc chromate can cause tissue ulceration and cancer. A study published in the British Journal of Industrial Medicine showed a significant correlation between the use of zinc chromate and lead chromate in factories and the number of cases in lung cancer experienced by the workers. Because of its toxicity the use of zinc chromate has greatly diminished in recent years.
I have experience with aluminum 18 wheeler boxes. They all get spray foamed but the plumbing and electrical runs get done first. You don't want to have to channel out all of those runs after it is spray foamed. Put in extra empty electrical runs in because it makes adding and subtracting tech wires alot easier.
Great stache, Brian. Giving off Tom Selleck vibes 😎
was thinking Burt Reynolds vibe! lol
More Skip Novak vibes
I thought more of a Mexican vibe😂
Lmao at the stache! 😂🤣
Was thinking maybe Charles Bronson, but now leaning more towards the Burt Reynolds camp…
Hi, here in the UK we have many thousands of canal boats floating around the country mainly steel but some aluminium. I built one myself about 10 years ago. Most, if not all are spray foamed the main disadvantage you highlighted can be overcome as you can remove it with many tools but the quickest I found for larger areas is a wire brush on a drill or grinder although a bit messy it is quick and accurate. It can be sculpted with a router, or hand tools. It would eliminate several of the problems the condensation one sounding the alarm for me. As a guide it took three hours to coat a 60 foot by 6’.10” by 6’ high canal boat. About the same amount of time to sculpt it ready for lining out. Before spray foam canal boats did use fiberglass wool and polystyrene blocks and condensation was an issue.
You might want to get ahold of US Coast Guard, they may have some great insight on what to use. Also check with your insurer and make sure any decision you make will not make the boat uninsurable. Many homes in the US now are finding out that some companies will not insure homes using a spray foam insulation. Food for thought. The boat looks great!
I was going to mention the insurance companies denying coverage as well, some folks I personally know in Colorado and another couple in Florida are fighting with it right now.
That is a type of spray foam, not spray foam in general
@ good to know, I will try to find out what they both had sprayed.
Not only the type but how it was done as well. All the cases I have seen on this it was because they hired a shady company to upgrade the insulation in an older house which was not designed for it thus it can cause problems. Go take a gander at the Build show channel here on youtube they have a few video's on it and the problems of adding foam to an existing older house. It can be done but you essentially have to do some extra steps to ensure things don't go wrong down the line.
New build no issue as the house was designed for it. d
th-cam.com/video/hCZgv4K5aTk/w-d-xo.htmlsi=mj_Ri9GAp81rjqoF
This explains the issues with spray foam
I'm an HVAC engineer. I agree with the spray foam group. Make sure to put in plenty of extra conduits. Also, I can't agree more with your comment on covering up the structural webbing! Even the vertical ones that you will be attaching your interior panels to. I consulted on a metal frame building where they spray foamed between the vertical supports but had nothing covering the supports inside or out. They attached metal siding inside and out. They had massive amounts of condensation inside on those vertical supports because of that. I would suggest radiant insulation bubble sheets or some type of thin insulation over every vertical webbing. Another thing to consider with spray foam insulation is that as long as you get a good bond to the aluminum, it will add extra rigidity to your boats hull. So definitely go with the spray foam!
The big caveat here is the spray foam need to bond to the aluminum. You saw how bonding to aluminum is not easy when you painted Maggie. You probably should etch the aluminum first the clean and apply a bonding primer if you decide to go the spray foam route.
Mechanical engineer + teacher at a technical high school here.
If air from inside the hull can get through or into your insulation, you definitely will have condensation and it would surprise me if there weren't any downsides to that (like mold or corrosion).
There are two ways to combat this problem:
1) Spray foam: Sticky mess, but in my opinion the ONLY sure way to completely eliminate the problem, because even if the foam were to crack, the problem would be VERY localized (no undercreeping to the sides on the foam/metal interface and thus creating a large affected area).
2) Make everything removable and create a truly airtight seal on the inside of the insulation layer with a plastic barrier film. If you have a problen then, it would not be as localized, but easyer to repair.
Maybe a combination of the two would work: Put sprayfoam in (2/3rds of total insulation thickness), don't lay any cable runs into that layer. Then put removable insulation on top of that, any cable runs should go into that removable layer for ease of access and to prevent condensation inside the pipes.
Even if spray foam is a no-go for you (and I totally get it), I would suggest to at least stick the foam to the aluminium at all large surfaces so there is no air gap behind the foam for most of the insulated area.
Good suggestion
Can you find any reason not to embed conduits within a full depth of spray foam and then incorporate access ports that could be used to alter plumbing or electrical etc. in the future? Obviously if there's damage to the hull the whole thing needs to be cut out and repaired regardless and as such a provision made for any less significant repair within the structure would alleviate the downsides of using spray foam throughout wouldn't you agree?
Hey Brian I Don't know Much about aluminum but as someone who lives in a steel school bus (And has been studying the ins and outs of the lifestyle for a little more than a decade) I would recommend doing the thermal coat to prevent corrosion and then using spray foam for insulation, my advice is to run conduits through key points in the frame before applying the foam and installing access points that can be used for later maintenance for wiring, plumbing, things like that. I plan to do largely the same with my bus, Although I don't plan on encountering nearly as much salt water so I will hardly need the corrosion resistance If everything goes to plan..... and let's be Honest if I do I probably have bigger problems XD . Hope you folks have a wonderful week god bless you XP
K-Flex ECO is a great option. It's a halogen-free, closed-cell elastomeric foam insulation that's designed specifically for marine and shipbuilding.
Non-Halogenated: Complies with U.S. Environmental Department standards.
Temperature Range: Can withstand temperatures up to 250°F (300°F intermittent).
Environmental Safety: Free of CFCs, HFCs, HCFCs, PBDEs, formaldehyde, and fibers.
Antimicrobial: Contains an EPA-registered antimicrobial agent to protect against mold, fungal, and bacterial growth.
Moisture Resistance: Resists moisture vapor intrusion, making it suitable for various marine applications.
ABS (American Bureau of Shipping) approved for use on ships.
I am a chief engineer in the USMM, I have seen the USCG come abord and inspect are ship and found USCG noncompliant (not green colored foam insulation installed and made us remove it), if you are considering using your vessel commercially.
Love your show keep up the good work.
I am familiar with several insulating products but I had not heard of this product before, after a little googling it seems like a good product.
I have no idea about warmer climates but if it's cold then spray foam is superior. We've been on boats that have had it all, spray foam, mineral wool, flexible closed cell foam panels, rigid foam panels, spray cork... The requirement that we placed when we were looking for our current boat was that it had to have spray foam insulation.
Spray foam is not about the ease of application but providing a proper moisture barrier. Spray foam might scare if you are not used to it, but it is easy to remove small sections of it if you for some reason need access to the hull. But how often do you need that? The hull will not secretly rot away behind the insulation (and with time you'll learn to trust that).
Anything else, including the closed cell foam panels (especially if not glued on), will leave enough space for moisture and condensation to form between the hull and the insulation. Trying to leave an "air gap" between the hull and insulation is desperate, it will not help keep things dry.
I just want to repeat this; if you have insulation that is NOT directly stuck on the metal then you will have moisture there. Insulation needs to be applied in such a way that it is airtight. Spray foam naturally forms a barrier like that. Pushing foam panels onto the "insulation pins" you showed won't do that and you will have condensation behind there. If you use foam panels (glued on) you will need to try and create a vapour seal, this is possible in a house but really hard to accomplish in a boat..
If you do go with flexible closed cell foam panels, I would recommend gluing them on and not using "sticky back" panels, unless you are completely sure about the quality of the sticky back, because the glue on those seems to be not as good as if you were using a separately applied glue. See for example K-flex/Armaflex, who provide sticky back panels but also sell normal panels and a special glue to go with them; we've found that using the separate glue is more reliable in the long run. It'll also be a bit cheaper and not that much more time consuming to install. Sticky backs hold first but later on can come undone.
Even with spray foam you will probably have some aluminum ribs exposed. You'll quickly learn that those transfer heat and form condensation like crazy. A bit of moisture won't hurt though, it's aluminum! One option that you could also explore would be a thin layer of spray cork. This would be applied before the spray foam possibly only onto the ribs which won't have foam. This won't insulate much but will help a great deal in preventing condensation.
If you want to talk about insulation and cold weather stuff, get in contact with me ;)
The spray on is how we did it but you want to have any of the electrical and plumbing done and use a pipe or tunnel to keep the space of the lines so in the future u can run new items through the same space . We used a 3 inch duct to accommodate that so the inside wall is smooth or convenient to push or pull lines without having to open the wall space
You can also use a pig and air compressor or vacuum to pull a messenger line through your conduit even if it's not smooth inside.
With just the options you mentioned in the video, I’d go with the spray on membrane, then the foam. Then with the, I assume removable panels you cover the walls with, I’d attach a self adhesive sound absorber. Like what’s attached to panels and floors in cars.
There’s many options and thicknesses, some are like butyl-ish type material, some are like foam gasket type material, some are covered in foil like for engine bays and what not. I just feel like the sheets of sound absorbing material on the back side of the paneling used to cover up the walls will be very multipurpose and easily maintained. Reduce noise, reduce vibration, reduce moisture wicking, easily replaceable.
There’s many options and thicknesses, some are like butyl-ish type material, some are like foam gasket type material, some are covered in foil like for engine bays and what not. I just feel like the sheets of sound absorbing material on the back side of the paneling used to cover up the walls will be very multipurpose and easily maintained. Reduce noise, reduce vibration, reduce moisture wicking, easily replaceable.
Hey Brian... another +1 for spray foam here. We are a general contractor and sprayfoam prevents thermal bridging which reduces condensation risk. In addition you wont have corrosion, or have to worry about mold. While I'm not in a boar we build homes in some of the coldest environments and have seen what happens to a house when condensation and moisture build up. Have a de humidifier installed for good measure but otherwise spray foam it
For insulation pins, I've had one of those go into my hand, when I leaned where I should not have. Perhaps, recycled plastic insulation pins / anchors might be less prone to injuries?
Thanks for letting me actually see you, shake hands and walk around your magnificent boat coming to life. Thanks Brian for being the authentic way you are and not sending me off. Do you get many unannounced visotors like me. I did not want to hold you up - so I didn't ask too much - thanks! Visiting meant a lot to me.
Here are some thoughts I'd like to throw out there - for whatever it is worth.
I believe thermal insulation and sound proofing/muffling tasks have separate philosophies.
The dew point is the temperature where water vapor in the air turns into water. Your boat will most likely always be sailing "at sea level" so higher altitudes do not play a role for you like in avionics. But maybe you can get some ideas there. Airplanes need to stay light weight while reducing noise and keeping the inside warm for passengers. One measure could be to prevent the humid air from accessing the location where it would condensate.
For sound proofing I think the task is 1. to prevent the hull from conducting/transmitting sound throughout the hull or resonating like the corpus of a guitar and 2. not let sound from outside of the hull pass through to the inside.
One extreme to sound-proof, would be to fill the inside with something like dry sand. Sound waves would agitate the grains of sand which would absorb and muffle the sound.
There exist self stick asphalt mats that can absorb some of the vibration. They are installed in some cars to prevent the thin steel of the outer hull from vibrating - but they also smell bad.
Maybe you can get some answers from air and spaceship manufacturers.
Cheers and more good luck on all your endeavors!
And Y'all stay healthy, happy and the way you are!
Have you considered zinc chromate? US military uses it on it’s aluminum aircraft to prevent moisture and corrosion ,, it’s also used on ocean oil tankers , I know there are dozens of applications for it ,,
I was going to suggest the same thing. Zinc Chromate makes it easier to inspect for corrosion or damage.
G’day Brian my name is Glenn Dawes I’m out of Fremantle Western Australia my history is refrigerating fishing vessels.
I would suggest from my experience to tar apoxi seal the aluminium first so as to isolate the hull from any electrical or chemical reaction then spray foam polyurethane 2” minimum.
As you know, aluminium is a brilliant conductor, so try to cover as much of metal as possible.
I find this is the best long-term treatment and have had good results over many years from installations.
Cheers Glyn
my last aluminium boat was insulated original with some kind off hard foam that was fireproof I have noe idea what product it was. I added more insulation with the armacell with tape on the backside and its a really really demanding job and almost impossible to get a good result. I have had boats with armacell and rockwool before and they are okay. but iff I could choose I would have gone for the spray solution to avoid cold bridges. I live in 67 degree north in Norway so you know the climate. I have been in same situation and no doubt about the spray on solution. how many times would it happen that you need to go behind the walls and do something. ? and I hope that you are planning to weld brackets over the deck where all your bolt on gear is so you don't need to bolt tru the deck
I worked in a small datacenter that was built in two phases. First phase used bat insulation resting on top of the ceiling tiles, the second sprayed insulation on the bottom of the roof. Later that year when it snowed the snow on the spray on roof lasted two days longer than the bat roof, which melted first day. By the time the snow arrived phase 2 had about 80% of the load of phase 1.
As a steel boat owner who has lived through a boat fire i don't recommend foam, carpet or any petrochemical based stuff. I do also wonder about what off gassing foam does. I used woolbatt insulation in the head lining as it's easy to remove/ replace when you want to inspect or run another wire etc. i have cork tiles on the walls, doubles as a corkboard for pictures. Will be obvious if water ingresses so will be able to arrest the issue early. It also gives a great natural feel. You may wish to consider how you would finish the interior of the boat, cork may be more expensive but may mean you don't have to line the interior. You can take advantage of the area inbetween the stringers like a "bookshelf" to have loads of storage without having to do the deep dark pit of top down storage. Have my boat just up north in Hervey bay if you interested in checking it out.
Closed cell spray foam is what you want to use. Waterproof and creates great barrier to prevent oxidation. Run conduit to any places for suspect future upgrades to get wire there and you’ll be golden
Seacork - it's spray-in, but natural... Potentially heavy though
Spray foam is the absolute best option for your application. Plan ahead for your wire runs and plumbing. Run pvc rigging tubes anywhere you think you might need access in the future then spray the heck out if it. You won’t regret it
Run tubes that are far bigger than you think you will ever need & use radius bends in them, run a minimum of three 1 low voltage 1 high voltage and 1 for pex piping water.
Brian, you're getting advice from everyone with good intentions. Considering the goals of preventing condensation, insulting the boat, fire resistant material, noise reduction, and potential problems of future repair or replacement - I would set aside the concern of how hard it might be to repair structure. :¬) Webhead USA
Spray in insulation is going to be the best bet. but if you really hate it, you can use a coating then insulate like you were describing. for any exposed ribs you can use a foam tape to cover it something like permawrap works great on the yachts we service.
Cork is less inflammable than polyurethane and If it's decently ventilated won't suffer from Moisture. Cork pannels are easy to replace too.
Cork rots when wet, like most other natural materials. In former times it was used to insulate fishing boat cold storages, but infused with tar to keep it from rotting. Not so nice on a modern boat.
In boats and RVs, there really is no way around moisture-blocking foams.
@bimodo1472 it can Moist but for a vast majority of area it's decent. I get your point, but there a quite a few expedition sailboat insulated with projected Cork or Cork pannels. Personnaly i prefer to change a pannel every One and then than insulate with a very inflammable material. But i guess that's down to preference
Apply 10-20mm of closed-cell spray foam and then use the insulation batts to achieve the desired R-value. My experience is with houses, but a two-material approach might get the performance and flexibility you desire. Good luck and thanks for taking us along on the journey.
Spray foam 💯 percent!!!!! If you’re worried about any repairs , either way you’ll have to somehow remove a section of the insulation to make a repair.. the good thing about the spray foam is you can keep a case of cans of spray foam for repairs…
Don’t overthink this one
Hi I made and lived on a aluminum boat in Norway. Here the weather changes from +25 Celsius in the summer to -25 Celsius in the winter. So insulation is essential for comfort.
My best tip is to allow moisture and water to drain in between your hull and the insulation. It means you have a good bilge pump system to keep pumping the water out.
But in my experience it’s the best way to build an insulated aluminum boat.
You don’t want to stick anything to the hull. Because all of that insulation is highly flammable. So if you need to weld anything on your hull. It’s going to be a problem.
I ended up using same type of insulation as the black pads you showed. But much thinner. To make the cavity between the hull and the inner insulation. Since it doesn’t absorb water and is rigid. On the inside, i used rockwool (an insulation normally used for bathrooms in houses, to prevent mold).
I think you'd be wise to survey contemporary builders of aluminum watercraft. In fact, if I were doing what you are doing, with money and lives at stake, I'd seek out an expert from one of these firms and pay him a consulting fee to answer these and other questions. Rather than guessing and soliciting lay advice, I'd strongly recommend paying for true, demonstrable expertise. Expensive, no doubt, but far cheaper than living (or dying) with regret.
Steel boat owner. We have panel insulation, with additional insulation over the ribs. *any* exposed metal will get condensation, its a fact of life because we breathe!
We solved condensation using airflow through the boat, which works really well.
Would I go spray foam? Yes, simply because of the time it takes to cut all the panels, fix them down (we used clips on the ribs) then tape everything, then find all the bits you missed, spray foam is much much faster. You have exactly the same issues with wire runs, as they are often under neatly taped and double insulated panels. The solution there is to run them in bundles on top of the insulation rather than under it.
Repairs are actually easier with spray foam, the panels always get destroyed when you remove them, you will never get the same panel again to replace it, but cans of spray foam are easy to find and store.
You should send your question to Boeing. They have to insulate aluminum aircraft and the worry of condensation is far more critical. I'm sure they would be able to provide you with some great ideas.
Correction? Boing is a mess and a failure. I would consult SpaceX
Boing still has some of the best technical people in the industry - their management, QA, and sales people on the other hand are a different matter, they seem to go out of their way to put fatal flaws into what would have been good work. Getting in touch with one of the good technical people might be very difficult. However, some of these people actually publish peer reviewed technical articles. As an engineering nerd I can say this. Somewhat there is a nerd sitting in a development lab who love a chance to speak to another human.
Hi Brian …. A fan since a long time. First time writing to you. Working in the plumping business as a foreman in the heating industry, pipe fitting etc…(sorry my french). My laid pipes are sometimes insulated with a great mildew resistant material called «Armaflex». Black-in colour , but paintable, this material feels like a very firm and form adapting foam. This material is pretty dense even though being very good insulation…. Often used for possible condensation risks…
In my industry it is glued on structure to be insulated AND together with a specific glue.
Very good cushioned feeling very good for accident under the waves. This material is amazing. You must touch a piece of it before making your mind.
Im mike from Montreal canada.