When patching holes where I have access to both sides, I like to bevel both sides. In this case it would mean 12 x 3/8 = 4-1/2” bevel. Also you can chemical bond in the middle if you patch the second side before the first is fully cured.
Yeah, I appreciate the idea here. Access on the other side was possible but difficult. Very cramped quarters… in the future I will probably try it this way. 👍🙏🙌
Congratulations! 43K views. I’ve been watching boat videos for years never has TH-cam suggested your channel. Then this morning you and your smiling face was recommended by the algorithm. I paused this video, subscribed, and went back to the beginning and binged the previous 37+ videos. All the while confused as to the low viewership numbers. Here’s to many more subscribers you deserve it. Fantastic work! Thanks.
Yes, this video seems to have reached more people than usual. I think it has something to do with the controversy of the “small patch/big patch” fiberglass debate. Haha. Anyhow, welcome aboard and I REALLY appreciate you checking out the other videos. 🙏🙏🙏👍👍🙌🙌
When are people going to learn that a 12 to 1 ratio is for a structural repair. Filling a small hole is not structural. It is a plug and as long as the bond between the old glass and the new plug is good the patch can be much smaller, simpler and lower in cost. I have done several of this type of repair to my boat. Some are now over 20 years old and there is no sign of deterioration. I have owned my boat for 35 years and have done numerous fiberglass changes/repairs and have never had a failure. All that is needed to fill a home from a through hull is two layers of backing, a 45 degree angle on the outside and progressively larger layers of alternating layers of woven and mat fiberglass.
Thanks for the feedback. For this hole up near the bow I think a structural repair was a good plan 👍 You’re free to do whatever you want with your boat 😉
110% agree with you and would that that laying up so many layers on the outside of the hull has probably made the future potential for failure and delaminating far higher than just a tapered core plug epoxied in.
@@livingforsail A simple, small plug has far less chance of failure, what you have done has a much larger chance of something going wrong. You are literally complaining during your video about how much work it is going to be, to restore the hull!
@@stephencroft761 Hey, thanks so much for jumping in and checking out the whole series. I imagine that takes a bit of time. It means a lot to me, so thanks for letting me know! Cheers!
Pro-tips: Any tool designed to cut or grind on stone, masonry, or tile works wonderful on fiberglass. Make a plastic tent around the work area using 1.5mil - 4 mill plastic with plenty of room to work freely. When grinding you can use a grinding dust collection cover so long as it does not interfere with grinding ability. As to the dust, if being done inside a tent I would suggest letting the dust fly inside. The important key, still use the vacuum but keep it inside the tent and at the working area being ground. Now your creating a negative air environment containing dust. when dealing with fiberglass using a fein tool, any bit that is diamond or carbide works great on fiberglass. Rotary rasps work wonderful on fiberglass as well. As to the bullworks I'd suggest an air hammer along with the hammer and chisel. When dealing with fiberglass it is ideal to write the layer number on them. This also helps orient them from scrim side to woven side. As to what is the important side of the fiberglass, does matter but matters less when vacuum bagged. Also I would in the future suggest using blue masking tape at least 2 layers on your antifouling. This helps keep the copper antifouling from getting resin on it. Also when doing a VACUUM bag job as demonstrated. Pre attach the vacuum bag plastic to the ""bottom"" of the work area on the tacky tape. Then roll up the lastic and protect it with an easy to remove layer of plastic. The idea is to not have resin issues with the plastic and tacky tape when trying to apply the bag after finishing the wet layup. My day job is working on luxury yachts in south florida.
Hi Jon!! I'm a little confused with the way that you are filling in the patch. You appear to have started with the largest patches first. Since the grinding made a concave depression into the hull, I've always started with the smallest patch working my way out with successively larger patches to slowly fill in the concave shape as i have gone along. In this way you build up layer upon layer with each overlapping patch that binds to another layer of the old fiberglass on the hull -- creating many layers of new fiberglass bonded to different layers of the fiberglass in the hull. It would seem that starting with the largest patch first, you are counting on that first single bond to the hull to support the entire 19 layer patch as each subsequent smaller patch will only be bonded to the new fiberglass layers, and they will not each have an independent bond to the hull. It seems like putting all of your eggs in one basket to do it in this way -- should you have any issue with the initial bond on the largest patch, the entire 19 layers could conceivably all separate at once from the hull -- I know that the vacuum bagging minimizes the chances of a poor bond, but i just thought it was worth pointing this out.
The direction/order of patches seems hotly contested on the interwebs.. I always followed the smallest to largest method, just seems to make more sense..
This is a much debated topic and it’s probably fine either way. This is how WestSystems recommends laying out the patches. At some point you are relying on the chemicals to do their job and prep is important. Probably more so than the order of patches. The school of thought with this method is that you get one very large sturdy bonded layer and the. The subsequent layers are all chemically bonded. Using epoxy I have little concern because it sticks to everything really well. I also like this way because it eliminates the small voids that can turn up at the edges of the patches. I think either way it will work 👍🙌
LFS hi from Alberta, Canada. Enjoying a fresh new sailboat restoration channel. Building the boat shed at home versus renting space at a yard an excellent decision. Work when you want as long as you want and no drive back and forth from a boat yard. From one retired PEng to another well done.
What a big job! I really admire how systematic you are in tackling it. When I removed the paint from my hull, I used a small Makita 9031 handheld belt sander, like the one Andy from Boatworks Today uses. I also experimented with a larger belt sander, but it didn’t work out as well. If I were to do it again, I’d definitely consider trying a woodworking electric planer instead. I was a bit surprised that you didn’t go with the West Systems epoxy, any particular reason? Wishing you a Happy New Year! 😊
Thanks! I think you’d find the hawk epoxy to perform just as good as the west system. The folks at SeaHawk are helping out with the epoxy and it’s great stuff with top notch specs 👍🙌
I’m an old sailor and motor boater. I’ve been boating since I earned my first professional paycheck after college and thru law school and after, owning seven boats and having a waterfront house on the Loxahatchee in Florida. I am more lazy and pragmatic so I would have repaired the thru hull fixture and save all the effort and work with pretty much just as much safety.
Haha! Great idea. That would have been one way to tackle the project! I like where your mind is at but I think I’ll need to put that hole in a slightly different location. 👍🙌
Dang, this refit video series is so exciting and interesting! Restoring fiberglass is a huge interest of mine and I also repair all manner of 100-year-old building construction crap-ola so I see so many, numerous processes, skills, and tools that transfer over to boat glasswork. I lack the chemical knowledge of the materials (polyester, vinylester, epoxy, waxed/unwaxed, etc.) but I will get there, eventually. Repairs are almost always much more work than new builds and construction because of the demo phase. Careful demo is the best demo and this guy's demo is surgical perfection -- exactly what's needed for the cleanest and dryest resin-based repairs. When this man finishes the bulwarks, they will be superbly strong and capable of handling whatever mooring/hawse forces, trampling, and abuses that a hardy crew can dish out! My gut says to go with stiff sheet goods as bulwarks infill and save the foam for a nonstructural application. I freaking love the drill, chainsaw, and die grinder method of precisely removing all that old plywood. Small tip about die grinding on metal -- it *will* inject small metal darts into *everything* within a ten-foot radius (skin, clothes, cats, etc.) Wear leathers if you clean up welds and stuff with a carbide die grinder. I am tickled that the vacuum-shrouded concrete grinding setup works so well! The 12:1 scarf looks like it will do the trick to reinfore that lower stem where it's most vulnerable to shallow-water grounding forces and subjected to the infinite pounding of waves. One of the main problems with balsa-cored hulls that the topsides are subjected to relatively light-but-endless wave pounding that delaminates the outer glass from the balsa and then proceeds to pulverize the core to balsa dust inside the layers. So, beefing up these thruhull patches with long-ratio scarf patches is a great way to go. Aladino and Andy are such awesome examples to learn from. Stay warm and dry this winter, guys. and Merry Christmas!
You do such a great job on these videos, Jon! Great work! Also, was surprised and glad to see Narwhal!! The video you shot of my boat had slipped my mind... too many boat projects still going on I guess A couple things. I found the bubble wrap to really help with drips if you can get it to stay up. Wind was always my issue. Also, I second scraping the multiple layers of paint off the bottom with a sharp/wide scraper with one added step. When I did Narwhal, I used TotalStrip by Totalboat. I slathered it on quite thick as I had multiple layers of old bottom paint. I would apply the Totalstrip from waterline to bottom of keel about 2 feet at a time, then I taped 2 foot wide sections of sheet plastic, (or some kind of rolled plastic wrap) and lay it over the Totalstrip smoothing it out to get as much air out as possible. I left it overnight. The next day I removed the plastic a section at a time and ALL the bottom paint came off like soft butter onto a tarp under the boat. Doing it a section at a time is important as to not let the totalstrip dry out while scraping. Final sanding was a breeze as it was just to clean up the gel coat with so much less dust. I have a gallon of the Totalstrip left over that you are welcome to have and try it. Could drop it by if you like.
The hard layer between the original fbg lay-up and anti-fouling paint is likely to be the epoxy barrier coat, applied to prevent osmotic blistering. If your hull has few or no blisters, the barrier coat did its job well. Greg, retired marine surveyor
Thanks Greg. I never really considered that it might have had a previous barrier coat done. It had some, but few blisters when it was hauled out. I wish I would have marked them at the time… 🤦♂️
There is a small hole. No structural compromise. why not grind it down somewhat. Put some glass on it, backfill it, smooth it, done. This looks like total overkill.
Some other guys and I rented a house while on a job in Alaska. Outside was a home built greenhouse. The floor was gravel. It was wood framed. The outside of the framing was covered in a clear material, and so was the inside. On a cold, sunny day it was much warmer inside than outside. It had a vent and fan and small heater. There was electric running out to it. It was empty and not being used, so I did not mess with any of that. I just went out to check on how the basic structure was working a couple times. It seemed to be a good deal. I think a heavy visquene lining held up with some lath would be just the thing for your shelter. Thanks for the videos. Take care.
Wow, busier than a one-armed banjo player, this episode Jon😅 It's good to see things getting sorted, toe rails turning out nice mate. Merry Xmas to you and your family as well.
Is it possible the black layer under the paint was a coal tar epoxy barrier coat? Did you determine what and how the animal was getting in? Isn't it more common place to start with the smallest patches and work out to the largest ones? That way you have only one edge showing when you are done. It makes a smoother patch all the way cross with all the other edges underneath the last layer. For your regular vacuum hose, could you insert a funnel into it to broaden the area of suction coverage? Do you intend to wrap fiberglass strips over the top of the bulwark once it's filled? I don't remember seeing one originally.
Hi! Lots of good Qs here: the patch order is heavily debated. Marine experts (from my research) tend to recommend largest first. One reason being that IF there is any material knocked back during fairing, it is your smallest, least structural patch. You also get the largest overall bond with largest first. Epoxy is so strong and sticky that it probably doesn’t REALLY make a difference 🤔. For the vacuum, the breather acts as a distributor for the pressure. And yes! Planning to wrap the bulwark cap when it’s dry/rebuilt! 🙏👍🙌
You would probably think so but the geneal school of thought is largest patch agains the hull for the best surface area bonding. Ive seen it done both ways but i think this is the generally accepted best method, but i agree it foes seem counter intuitive
I will also agree that it seems counterintuitive. This is the method that my research has landed me on… I think either way would be fine if properly prepped and rolled out for voids. Epoxy will be your friend for a repair like this. 👍🙌
The main reason none of this matters is epoxy is a glue and a laminating resin. I always liked small to large as it left one with less hairy edges to grind and fill .
I watched “the long way around” when it came out about 20 years ago and always wanted a BMW ADV bike after that! Haha. It’s a pretty fun machine! Gotta love the Fein tool also. You’ve gotta love the German engineering! 👍🙌
@livingforsail well, I'm German and I love good stuff. Sadly we are forced to produce to a lower price point nowadays. Chinese competition doesn't have a positive impact on quality.
@@livingforsail yeah, very challenging times. Chinese competition, Putin's war, and tariffs in sight...many things have changed and many more will. Anyhow, I wish you success with your project!
I don’t think I’ve seen many thruhaul repairs done to this high standard. I don’t doubt your research/approach at all. (but it would be interesting to know the incidence of failure in those lesser jobs) perhaps they arrived at Davie jones locker never to be heard from again 🤷♂️
I know the Gougeon brothers say that, but had you went with 5 inches wide, it would have been more than enough, specially if you reinforce it from the inside. I wouldve kept away from the stem for that is such a strong section of the boat. some things are best left undisturbed , to my view.
Your paint looks like an old paint system i applied many years ago, about=1978. It was a system a adhesive layer, 5 or 6 coats of epoxy tar and then again a adhesive layer between the antifoul. It was from Sikkens, the Netherlands. Later sikkens was into the AKZO NOBEL group.
Interesting, I've just commented on this stuff too. I never knew what it was. 1978 would have been about the time it was applied to by boat. Thanks for the info.
i would suggest using a heat lamp. for that size you would need a multiple bulb fixture. It will eliminate the necessity to heat the entire shop to the required temp for proper curing of the epoxy
Greetings from New Zealand, look grinding all that paint off is easy and the New Zealand Navy just did it to their only very expensive survey ship ... you just run it onto rocks and burn the paint off ... well that's how the Real Professionals do it and Kiwis are the best boat builders in the world so ... we'd Know ... so long as no one gets killed and keep saying how amazing it was that no one died
Hi I like your clear engineering approach however I think you might like to consider an alternative that you may not be aware off? Dust has always been a major issue with glass however it can be completely mitigated by the simply addition of water! Wet sand and you will never look back and of course you can always use a diamond planer instead of a sander. Just saying….. been around glass boat and cars for over 40 years! Cheers! Ian
Hi. Thank you 🙏. I’m always interested in new ideas and other ways to look at things. I’m not a pro here and have much to learn. I’m grateful for these constructive tips. That must make quite a “slurry” of glass paste. Do you just towel it up and dispose? What kind of sander do you use for that? Cheers.
I would suspect that the last layer you were sanding and found to be difficult was an epoxy barrier coat which is applied over entire hull to prevent blistering.
I’ve had good luck with bottom paint stripper. It’s pretty mild as paint stripper goes, certainly needs a little ppe but not like the old style old stuff for removing all paint. Just apply and then immediately cover the stripper with plastic sheet so it doesn’t dry out.
As for the Black layer on the hull; I had a tar or tar like layer below my antifoul, it was there from a long time ago; 30+ years. The antifoul never adhered to it well and last winter I had my hull blasted down to the gelcoat, blasting had no problem with the black tar coat. The blasting remove some gelcoat, but I think it was only removing the 'bad' gelcoat. The hull is GRP layed up in the 70's. I think the basting was the best thing for me. It exposed the bad gelcoat that then needed filling and an epoxy sealing coat, but I happy it was done and the repair will last a long time.
I think that sounds good. I might opt to do that on the way back to the water when we are at the yard. I think trying to blast inside the shed will be a HUGE mess! Haha.
when doing a repair like that I prefer to grind bevels inside and outside. That way the depth you are grinding to is decreased and the bevel width is less. In other words, if your hull is 0.75" thick and you grind half way through (0.375") the 12:1 bevel only needs to be 4.5" wide. Grinding bevels inside and outside will result in you doing half as much grinding. Also you will be getting new chemical bonds in the center of your repair when you lay up glass on both the outside and inside of the hull. Another option is to do a cored repair where you insert a piece of core material and then put a glass skin inside and outside. Use a closed cell core material such as divinycell foam. Alternatively you could use a piece of G10 epoxy glass sheet for your core. If you do that your glass skins require a much smaller bevel width since they will be thinner.
Hello I’ve been working with West system for 20 years on my three last boats and your right! in theory the 12 to 1 bevel is what is recommended by the Gougeon brothers. But since your boat was overbuild like most boat from the 70 early 80 you could of gone with a much smaller bevel (6 or 8 to 1)that would of been as strong. Also I’ve been thinking all those years about the small to big or big to small dilemma and personally I think there is advantage and disadvantage on both technics so my last holes that I’ve fill, I do : big to small the first half of the way and I finish it up with the small to big layering. The last two layers I will use mat fiberglass to ease the sanding. Also even if the styrene that bond the mat together is not dissolve by the epoxy, since it’s a pretty flat surface at this point , it doesn’t really matter if the mat stays stiff. I’m filled with anticipation to see how you are going to apply those giant first layers… maybe I would consider layering them on a piece of mica and then tape and vacuum them to the hole .
That dark layer is an indicator layer, likely with graphite powder in it. It is tougher to scratch through so it can show you when you've breached your gelcoat on a scratch/gouge.
As far as grinding the hull goes, the more aggressively you cut the glass the must dust you get. Aggressive make big chunks which do not get airborne. Do the rough cut with the concrete grinder and then a small shallow cut to clean up the gouges.
This is a BIG debate…. You can check the comments for both sides of the story. Either way will get the job done. Using epoxy is going to be a step that will help ensure a good result. I think it’s a bit counterintuitive, but for marine applications most experts recommend the largest patch first and that drive my decision. 👍🙌
When I stripped my hull down to its original barrier coat, I used a four edged hand scraper. I found that when it was very sharp, I could pull one blade width of bottom paint for a full length of my stroke down to the base material in one swipe. I would get about 5-6 swipes per edge and then rotate to the next edge. After all four edges had been used, I would use my Dremal to retouch all of the edges and continue on. It was much faster than sanding and much cleaner than sanding or stripping. It left chunks of paint rather than dust or toxic goo.
I used homemade dust collection both at the source and from the air. I wish I had Doors in both sides but only one. Collection from the air is critical.
Small to big. The way it's done here, only the first layer has a mechanical bond and all subsequent layers function as filler only. You want each layer to have a structural/mechanical bond to the parent material(hull). Fixing a fuselage in an modern aircraft using the method shown here, they'll charge you with a murder attempt.. 😉🙂
Aerospace runs small to large. Marine runs large to small. This again according to the experts I’ve talked to and no one needs to be charged with anything 👍😉
I'm assuming the plywood in the bulwarks was just filler, not for significant strength. Why not just refill with epoxy mixed with high strength filler like West 404 and maybe some chopped up fiberglass?
This boat has a funky hull to deck joint and I think I’ll sleep better with something a bit more stout in there but yes, it seems that much of the bulwark was just “filler”… also we have bulwark mounted stanchions, so I need strength there. 👍🙌
I think your calculations are off for your patch, 12:1 is correct, but you should be doing it from both sides (assuming you can get to the back side) which really means that as you are attacking it from both sides, the taper you need is effectively for half the hull thickness, or a 4.5 inch taper on both sides, which makes for a 10 or 11 inch diameter patch.
These are good points but I believe 12:1 is most common with many other scarf joints too -- this just happens to be a circular scarf. Most wooden aircraft wing spar repairs are required to have a 12:1 scarf joint to be considered airworthy. And even though we can find boatbuilders using 6:1 to build plywood-only dinghies, most butt-block replacements in wooden-planked boats are retroactively fitted with two-foot-long, double-ended scarf patches that closely resemble (in a linear manner) the type used for Jon's thruhull removal fiberglass patch (in circular shape). Both Aladino and Andy confirmed that a single-sided repair provides the necessary strength, so I'd go with those sources. It's a lot to visualize so feel free to pick apart my wordy explanations and I will try to find more references. It is worth noting that the fresh backing plate that Jon installed is also chemically bonded to the new, outer patch because he installed the outer glass while the innter backing plate resin was still green/tacky. So his outer patch is now, also chemically bonded to the inner hull surface in rivet fashion with that backing plate. Wooden scarfs (scarves?) are slightly different in that they benefit from stronger glue bonds than the purely mechanical bonding of a new-to-old glass-to-glass joint. So a 12:1 fiberglass scarf gives you the needed mechanical strength when going from old-to-new glass. Check out the channel called Building Temptress for some more examples of 12:1 scarf joints -- Dan Lee is amazing.
@@scottcates I agree, I didn't say anything in my response about changing the taper ratio. Its still 12:1 the only difference is because you are doing the patch from both sides (as you're supposed to) you are effectively trading the hull is if its half the true depth. otherwise all you are doing is grinding away the patch you just made! Just saying that because of the way he choose to make the patch, the ground area is way larger than it could have been under normal circumstances.
Doing it from both sides is a good approach. I probably could have pulled that off but it’s very cramped in the bow and I felt a could get the bevel better from one side. The experts I talked to said with a 12:1 bevel and good prep, nothing to worry about 👍🙌
Awsome stuff! Love the details you provide in your video's. Your transitions are cool as well. And your edits are great!! Can't wait to start my own sailboat build ( check out the "polar 44 sailboat") not fiberglass, but still a massive project.
Thought about it… too many leak paths to get a decent vacuum… you need to be Into the micron range over 29”HG to get a boil at ambient temps… Good thinking though. 👍
CSM bonds better as base layer,however you make a good point regarding fairing but remember if your grinding into biax cloth or chop in the process of fairing your lamination is wrong, not wrong in the way it’s no good at all. You should never go into any laminated cloth or chop when fairing. When your lamination is at the level required always make sure you can fill the weave and some. Some pros will use gel coat with micro balls to fill the weave on the first stage of fairing to insure they are not in any way cutting into the freshly laid material. However using a layer of chop as a last laminate as a sacrificial layer of sorts is a good safety barrier. You have gone to the trouble of following a suggested method I would lean to the advise from the individual who gave you that. Good point to raise and probably not considered at the start by many amateurs. Remember chop has next to no strength really it seals and seems to work very well as primary bond surface, better than the weaved cloth, so thinking it could matter on a repair that’s smaller and is under a lot of flex and twist forces. Some paper somewhere will have a detailed explanation on who goes first and why, I say it would be variable pending a lot of different factors.
CSM as a base layer stems from polyester (maybe also vinylester) repairs. It is not a factor in composite repair utilizing epoxy resins. This is true for marine and aerospace composite repair applications. I do like the idea of CSM as a sacrificial sanding layer and have implemented it in my "toy" sailboat.
@@projectseahorsesailing I have read that some say it helps bond layers because of the short fibers that "claw" into the substrates. I was told by West Systems that mixing in some micro fibers helps to improve the bond between old substrate and new laminates.
@@livingforsail Interesting, I was mistaken then. I was under the impression that it was only necessary for polyester. If West Systems says it improves the bond in epoxy as well, I believe it. Thanks
I put most of that stuff with links in the description. Let me know if something is missing and I can certainly let you know. Welcome, and good luck with the future repairs! 🙏👍
The 12:1 ratio refers to ratio of the scarf width (per side) relative to the thickness. So in this case, the “1” is the thickness of the hull (0.75”) and so each side of the scarf is 9” plus the width of the original hole (~2”) ends up with a nearly 20” repair patch. Taking the scarf from inside AND outside would have effectively cut the patch size in half (and is a good idea if possible) 👍
You shouldn't even worry about taking moisture readings until you've fully removed all sources of wet core. More important than temp is low humidity, get the air in the shed and inside the hull as dry as possible. Try a diesel or kerosene heater, an electric one will be way too expensive on your power bill. I don't know what the moisture readings are on your bottom, but it's safe to assume all older polyester boats are wet. Before you worry about any other repairs, you should strip the bottom paint completely and continue hunting down wet core every where else until it's gone. Sorry to say, grinding out the bevel from the old seacock was fine, but putting on the epoxy patch should have waited until you confirm the laminate isn't wet (however that thinner glass at the bow is unlikely to have retained moisture, so you're probably ok).
Also, I hate to say it... because I have mad respect for WEST as a company... but you can't take everything they advise as gospel! A 12:1 scarf was massive overkill on that small seacock hole. A 12:1 scarf is for wood which mostly consists of uni-directional fiber orientation with vastly different properties... Fiberglass does not mechanically behave like wood! Also, that area of the bow is, by nature, much more structurally robust than other parts of the boat's bottom. Based on the thickness of the laminate and the area that its in, a 6:1 scarf would have been more than adequate. Remember, this is modern glass weaves, epoxy, and vac-bagged... the properties are vastly improved over the boat's original hand-laid polyester or chopper gun application. Small to big on the outside patches, last layer should be a should be a thin CSM or you going have print-through (not a big deal on the bottom but better learn the lesson here than anywhere on the top sides). If I was doing a critical structural repair like a mainsheet track base on the cabin top, yeah I'd go 12:1... not for thru-hole repairs (and I've done a few).
Thanks for the feedback. I meant to include a segment about checking that patch area for moisture before proceeding. I was going to pull it down with vacuum and a heat lamp to help dry it if needed but it was bone dry! The moisture meter didn’t budge off of 0%… there is a person that has reached out to let me know or that they were in the yards back when they built the late 80s hulls and apparently used vinyl ester so that may be part of the credit for the dry repair area. 👍
@@livingforsail It was not at all common to use V.E. resin on production sailboats until the late 90's and even then it was only semi-custom and premium brands, they would typically only use the V.E. resin on the first laminations in the mold and then switch back to polyester. I'm not saying it isn't possible, but if they used any V.E. resin in your lay-up then you should find very few or no blisters and little retained hull moisture in the laminate. Fingers crossed this is true... When you replace the core in the bulwarks I hope you consider using Coosa board or a core foam. Avoid using any plywood, anywhere, of any reason.
@@SteelDoesMyWill Thanks for the info. There were few blisters on the hull. More paint removal will tell how the condition is... I am using some coosa and diab foam for the deck and have a few videos about that. I replaced a forward bulkhead with marine ply and went to great lengths to seal it with glass and epoxy. After all of that work I can safely say that I would 100% use Coosa for ANY ply replacement from now on.. it was a cost thing that probably was more expensive in the end... live and learn...
@@livingforsail I watched your deck video.. nice choice with the H100 and then Coosa in the middle for forestay + anchor windlass strength. One tip, don't roll raw resin onto the foam, only use a thickened resin for that. You'd be amazed at how much epoxy that foam will absorb. Because you had the two deck skins and applied clamping force I doubt you'd have issues with adhesion, but you'd have gotten away with far less epoxy overall if was a fluffy with 406.
I’m not sure I understand. I don’t have the original core from that hole. It was drilled 35 years ago in Taiwan. This effectively did replace what was there before (fiberglass) and the tapered scarf is needed to get a good mechanical bond.
I'm no expert but I'd a stuck a coosa board plug in that hole with epoxy and a backer inside. Lord that was a lot a work for a through hull fitting. Leave the fitting in there LOL
12 to 1 on that little hole is way beyond what's necessary. A 45 deg bevel would have been sufficient with a flat cloth patch on the inside, colloidal silica in the hole and slightly dished patch on the outside. Gross misunderstanding of patching a small hole.
@@livingforsail I can tell you from experience that what you're doing is way more than necessary, The load on that hole is insignificant at the depth of water that it sees. Assuming that the hole is three feet below the average water line in that area and that the hole is 2 inches in diameter which gives a hole area of 3.14 sq.inches and a water pressure (at that depth) of 19.6 psi, the total pressure on the hole would be 61.5 lbs. You could plug that exactly as I've described above and you would have no problems. On the other hand if the hole was 12 inches in diameter you would be dealing with an area of 113 sq inches and a total pressure on the hole of approximately 2217 lbs. That would be a different story and the 12:1 taper would be more appropriate...so I guess you can say you got a lot of sanding practice. You might want to look into learning some basic principles of hydrostatics.🐬👍
I made a mistake. The actual pressure on the hull is the difference between the water pressure on the outside and the air pressure on the inside. That's a total pressure on the outside pushing in of 4.psi which makes the actual force on the 2 inch hole even less. That's 13.2 lbs total on the 2" hole and for the 12" hole it would be 474.6 lbs. Still the same repair result. That's my final answer and I'm sticking to it. 🐬👍😂
@@ChrisTietjen_00 I think you might want to factor in more than just water pressure... It's the bow of the boat so I do want it to be strong and... again... this is what some experts recommended. I'm not looking for bare minimums here :)
Required bevel depends on the laminate underneath and only applies you you want to achieve original strength in the structure. According to the book we had in university, the minimum bevel for glass repairs (to achieve original strength) was 1:5 for chopped strand 1:10 for somewhat balanced fabric laminates 1:20 for UD laminate Then again, if you already had a 2" hole in there would you really need 1:10+ bevels? That is not really 'fixing' the laminate, rather you are just filling a hole and only requirement is for the patch to plug the hole and stay in place. Sure, fixing it properly is always better and leaves more options to drill new holes in the future without worrying about laminate strength. Bahco 665 scraper with diy vacuum attachment for bottom paint removal. Took me about 3.5 hours to scrape 50+kg (110lbs) of bottom paint (44years worth) from my HR352. Sure, there was ten(s) of hours fine cleaning with 6" orbital after that, but good quality scraper is the clear winner. The quality difference in paint scrapers is ludicrous. Even some 'good quality' scrapers are just useless.
I'm not an expert in fiberglass so please excuse the ignorance, but the order of the layers you're putting on seems back to front to me. Shouldn't the smallest piece be first against the hull, and then as you build up the layers the pieces become progressively larger, so that when the patch is done the largest piece covers all the preceding layers? The way you're doing it now there is only one piece of glass bonded to the hull, but if you do it from small to large the edge of every layer would be bonded to the hull. Wouldn't it be a stronger patch then?
This is a super relevant question and that assumption makes a fair amount of intuitive sense to me, too. In the world of fiberglass repairs, the experts that I've studied teach that either "direction" is adequately and strongly bonded. Small-to-Big or Big-to-Small seems to make no structural difference. But, yeah, it seems like a larger, outward layer would yield a flatter, smoother surface. Maybe the peel-ply-and-vacuum method keeps it all super flat as layers build up? I've never used vacuum or peel ply so I really don't know but everything I've studied seems to indicate it.
You can do it either way but this is an area where some people have strong feelings. If you are one of those people do it the way that makes you happy.
Big piece first so it has maximum bond area. If you start with a small piece, each piece has a small bond area onto original laminate. Also, you typically grind-off the bump in the middle, making a hole in the biggest pieces.
Great review of tools... but way overkill on the amount of taper. 2 inch on both sides of hole with a little Coosa plug would have worked. And epoxy only.
I was looking for a way to get the anti-foul off and Into my dustbin and not all around the shed. Knowing what I know now I’ll probably reach straight for the concrete diamond wheel and get both birds with one stone.
@@jackdbur That could be something cool to try. I have a one sided shroud that swings partially out of the way that would probably pick up some of the dust and be MUCH faster... Something to think about. Thanks.
That is way overboard for such a small hull repair. A 2” hole only needs a total of 8” circle back gouged into the glass. Of course west system is going to tell you to go way way too big. That means they sell more resins. If you can’t see that you are thinking !!
Um Gottes Willen, du schleifst ja den ganzen Rumpf kaputt. Innen und außen ca. 3 cm anschäften und von beiden Seiten geichzeitig nass in nass laminieren. Hält ewig und man hat nur eine kleine Repatarurstelle. So habe ich Borddurchbrüche (Toilette, Logge usw.) verschlossen und hält nun schon 15 Jahre!
wow … what a complete overkill and WOFTAM to plug 1 small hole and if you’re going to spend that much time over such a small hole you’ll never get to sail the boat. A piece of fibre board cut to fit with a slight taper and strong epoxy glue it in. Sanded down both sides and primed. 2 hour job tops.
I used one coat of acid & then with a floor cleaner with a about 15cm hand scraper got my boat down to gel coat. It a Fisher 25 😎& I forgot to say, Im a disabled sailor wheels on land 🧑🏽🦽➡️the boat on the water. 😄
@@user-tf6ny2kp9mmoon The boat guy, Jon, mentioned epoxy a few times in the comments here. So, maybe epoxy for the increased bond strength? What's the difference in your experience?
When patching holes where I have access to both sides, I like to bevel both sides. In this case it would mean 12 x 3/8 = 4-1/2” bevel. Also you can chemical bond in the middle if you patch the second side before the first is fully cured.
☝️💯
Yeah, I appreciate the idea here. Access on the other side was possible but difficult. Very cramped quarters… in the future I will probably try it this way. 👍🙏🙌
Congratulations! 43K views. I’ve been watching boat videos for years never has TH-cam suggested your channel. Then this morning you and your smiling face was recommended by the algorithm. I paused this video, subscribed, and went back to the beginning and binged the previous 37+ videos. All the while confused as to the low viewership numbers. Here’s to many more subscribers you deserve it. Fantastic work! Thanks.
Yes, this video seems to have reached more people than usual. I think it has something to do with the controversy of the “small patch/big patch” fiberglass debate. Haha.
Anyhow, welcome aboard and I REALLY appreciate you checking out the other videos. 🙏🙏🙏👍👍🙌🙌
When are people going to learn that a 12 to 1 ratio is for a structural repair. Filling a small hole is not structural. It is a plug and as long as the bond between the old glass and the new plug is good the patch can be much smaller, simpler and lower in cost. I have done several of this type of repair to my boat. Some are now over 20 years old and there is no sign of deterioration. I have owned my boat for 35 years and have done numerous fiberglass changes/repairs and have never had a failure. All that is needed to fill a home from a through hull is two layers of backing, a 45 degree angle on the outside and progressively larger layers of alternating layers of woven and mat fiberglass.
Thanks for the feedback. For this hole up near the bow I think a structural repair was a good plan 👍
You’re free to do whatever you want with your boat 😉
110% agree with you and would that that laying up so many layers on the outside of the hull has probably made the future potential for failure and delaminating far higher than just a tapered core plug epoxied in.
@@livingforsail A simple, small plug has far less chance of failure, what you have done has a much larger chance of something going wrong. You are literally complaining during your video about how much work it is going to be, to restore the hull!
@@mike_au Thanks for sharing
@@Onyourbiketoo Time will tell. Thanks for sharing
I found this video yesterday and binge watched tge whole playlist in 2 days. Great work!!!
Haha. Right on. I’m glad that you enjoyed getting all caught up. Welcome to the channel! 🙏👍🙌
Same here, I did it today Jan 5.
@@stephencroft761 Hey, thanks so much for jumping in and checking out the whole series. I imagine that takes a bit of time. It means a lot to me, so thanks for letting me know! Cheers!
Pro-tips: Any tool designed to cut or grind on stone, masonry, or tile works wonderful on fiberglass. Make a plastic tent around the work area using 1.5mil - 4 mill plastic with plenty of room to work freely. When grinding you can use a grinding dust collection cover so long as it does not interfere with grinding ability. As to the dust, if being done inside a tent I would suggest letting the dust fly inside. The important key, still use the vacuum but keep it inside the tent and at the working area being ground. Now your creating a negative air environment containing dust. when dealing with fiberglass using a fein tool, any bit that is diamond or carbide works great on fiberglass. Rotary rasps work wonderful on fiberglass as well. As to the bullworks I'd suggest an air hammer along with the hammer and chisel. When dealing with fiberglass it is ideal to write the layer number on them. This also helps orient them from scrim side to woven side. As to what is the important side of the fiberglass, does matter but matters less when vacuum bagged. Also I would in the future suggest using blue masking tape at least 2 layers on your antifouling. This helps keep the copper antifouling from getting resin on it. Also when doing a VACUUM bag job as demonstrated. Pre attach the vacuum bag plastic to the ""bottom"" of the work area on the tacky tape. Then roll up the lastic and protect it with an easy to remove layer of plastic. The idea is to not have resin issues with the plastic and tacky tape when trying to apply the bag after finishing the wet layup. My day job is working on luxury yachts in south florida.
Hey, thanks for all the good tips! Cheeers!! 🙏👍🙌
Great episode😎. Engineer by trade but you’re also one hell of a filmmaker and educator 🙏
Thanks for the support. I appreciate that! 🙏🙏🙏
This is AMAZING!!!! We can totally relate to what you are doing as we are doing something similar. It's all a labor of love for sure!
That’s for sure! All the best. Cheers! 🙏👍
Hi Jon!! I'm a little confused with the way that you are filling in the patch. You appear to have started with the largest patches first. Since the grinding made a concave depression into the hull, I've always started with the smallest patch working my way out with successively larger patches to slowly fill in the concave shape as i have gone along. In this way you build up layer upon layer with each overlapping patch that binds to another layer of the old fiberglass on the hull -- creating many layers of new fiberglass bonded to different layers of the fiberglass in the hull. It would seem that starting with the largest patch first, you are counting on that first single bond to the hull to support the entire 19 layer patch as each subsequent smaller patch will only be bonded to the new fiberglass layers, and they will not each have an independent bond to the hull. It seems like putting all of your eggs in one basket to do it in this way -- should you have any issue with the initial bond on the largest patch, the entire 19 layers could conceivably all separate at once from the hull -- I know that the vacuum bagging minimizes the chances of a poor bond, but i just thought it was worth pointing this out.
The direction/order of patches seems hotly contested on the interwebs.. I always followed the smallest to largest method, just seems to make more sense..
This is a much debated topic and it’s probably fine either way. This is how WestSystems recommends laying out the patches.
At some point you are relying on the chemicals to do their job and prep is important. Probably more so than the order of patches. The school of thought with this method is that you get one very large sturdy bonded layer and the. The subsequent layers are all chemically bonded.
Using epoxy I have little concern because it sticks to everything really well.
I also like this way because it eliminates the small voids that can turn up at the edges of the patches.
I think either way it will work 👍🙌
👍
Think if he went small first his last patch the large one is at risk of being ground into significantly
LFS hi from Alberta, Canada. Enjoying a fresh new sailboat restoration channel. Building the boat shed at home versus renting space at a yard an excellent decision. Work when you want as long as you want and no drive back and forth from a boat yard.
From one retired PEng to another well done.
Hello! So nice to have another Canuck onboard. 🇨🇦
It certainly has its advantages to be working from home. Haha. 👍🙏🙌
If you didn’t already figure it out, Canada is where Bridget and I are both originally from 👍
What a big job! I really admire how systematic you are in tackling it.
When I removed the paint from my hull, I used a small Makita 9031 handheld belt sander, like the one Andy from Boatworks Today uses. I also experimented with a larger belt sander, but it didn’t work out as well. If I were to do it again, I’d definitely consider trying a woodworking electric planer instead.
I was a bit surprised that you didn’t go with the West Systems epoxy, any particular reason?
Wishing you a Happy New Year! 😊
Thanks! I think you’d find the hawk epoxy to perform just as good as the west system. The folks at SeaHawk are helping out with the epoxy and it’s great stuff with top notch specs 👍🙌
thanks for the video. the decrease in dust production using the cement tool was pretty amazing.
It was a DRAMATIC difference! It also left a good “tooth” behind. 👍🙌
I’m an old sailor and motor boater. I’ve been boating since I earned my first professional paycheck after college and thru law school and after, owning seven boats and having a waterfront house on the Loxahatchee in Florida. I am more lazy and pragmatic so I would have repaired the thru hull fixture and save all the effort and work with pretty much just as much safety.
Thanks for the feedback 🙏👍🙌
Sterling project! I would have made the hole bigger, inserted a tube and a propeller, I know you will wish you did one day :)
Haha! Great idea. That would have been one way to tackle the project! I like where your mind is at but I think I’ll need to put that hole in a slightly different location. 👍🙌
Dang, this refit video series is so exciting and interesting! Restoring fiberglass is a huge interest of mine and I also repair all manner of 100-year-old building construction crap-ola so I see so many, numerous processes, skills, and tools that transfer over to boat glasswork. I lack the chemical knowledge of the materials (polyester, vinylester, epoxy, waxed/unwaxed, etc.) but I will get there, eventually.
Repairs are almost always much more work than new builds and construction because of the demo phase. Careful demo is the best demo and this guy's demo is surgical perfection -- exactly what's needed for the cleanest and dryest resin-based repairs. When this man finishes the bulwarks, they will be superbly strong and capable of handling whatever mooring/hawse forces, trampling, and abuses that a hardy crew can dish out! My gut says to go with stiff sheet goods as bulwarks infill and save the foam for a nonstructural application.
I freaking love the drill, chainsaw, and die grinder method of precisely removing all that old plywood. Small tip about die grinding on metal -- it *will* inject small metal darts into *everything* within a ten-foot radius (skin, clothes, cats, etc.) Wear leathers if you clean up welds and stuff with a carbide die grinder. I am tickled that the vacuum-shrouded concrete grinding setup works so well! The 12:1 scarf looks like it will do the trick to reinfore that lower stem where it's most vulnerable to shallow-water grounding forces and subjected to the infinite pounding of waves.
One of the main problems with balsa-cored hulls that the topsides are subjected to relatively light-but-endless wave pounding that delaminates the outer glass from the balsa and then proceeds to pulverize the core to balsa dust inside the layers. So, beefing up these thruhull patches with long-ratio scarf patches is a great way to go. Aladino and Andy are such awesome examples to learn from.
Stay warm and dry this winter, guys. and Merry Christmas!
Merry Christmas to you also! Thanks for the great feedback and I appreciate the points that you laid out. Keep in touch! 🙏🙏👍🙌
You do such a great job on these videos, Jon! Great work! Also, was surprised and glad to see Narwhal!! The video you shot of my boat had slipped my mind... too many boat projects still going on I guess A couple things. I found the bubble wrap to really help with drips if you can get it to stay up. Wind was always my issue. Also, I second scraping the multiple layers of paint off the bottom with a sharp/wide scraper with one added step. When I did Narwhal, I used TotalStrip by Totalboat. I slathered it on quite thick as I had multiple layers of old bottom paint. I would apply the Totalstrip from waterline to bottom of keel about 2 feet at a time, then I taped 2 foot wide sections of sheet plastic, (or some kind of rolled plastic wrap) and lay it over the Totalstrip smoothing it out to get as much air out as possible. I left it overnight. The next day I removed the plastic a section at a time and ALL the bottom paint came off like soft butter onto a tarp under the boat. Doing it a section at a time is important as to not let the totalstrip dry out while scraping. Final sanding was a breeze as it was just to clean up the gel coat with so much less dust. I have a gallon of the Totalstrip left over that you are welcome to have and try it. Could drop it by if you like.
Thanks Jeff! Great idea with the stripper. I might like to give that a try! Thanks!! 🙏
Loving the channel. Great work.
Thank you! 🙏
The hard layer between the original fbg lay-up and anti-fouling paint is likely to be the epoxy barrier coat, applied to prevent osmotic blistering. If your hull has few or no blisters, the barrier coat did its job well. Greg, retired marine surveyor
Thanks Greg. I never really considered that it might have had a previous barrier coat done. It had some, but few blisters when it was hauled out. I wish I would have marked them at the time… 🤦♂️
The dark layer could be Vc tar which was used as a barrier coat. I had to sand it all off my C&C. As you mentioned, it was a hard job removing it.
@@scottmilligan8321 Thanks, I will look that up.
There is a small hole. No structural compromise.
why not grind it down somewhat. Put some glass on it, backfill it, smooth it, done.
This looks like total overkill.
I’m following the west guide for the repair. Overkill maybe. It’s my time and $$$ 😉
I agree.
In any case: It‘s good craftmanship and worth seeing.
Some other guys and I rented a house while on a job in Alaska. Outside was a home built greenhouse. The floor was gravel. It was wood framed. The outside of the framing was covered in a clear material, and so was the inside. On a cold, sunny day it was much warmer inside than outside. It had a vent and fan and small heater. There was electric running out to it. It was empty and not being used, so I did not mess with any of that. I just went out to check on how the basic structure was working a couple times. It seemed to be a good deal. I think a heavy visquene lining held up with some lath would be just the thing for your shelter. Thanks for the videos. Take care.
Thanks for the ideas. Cheers! 🙏🙌
Nice job John!
Thanks so much! 🙏
Wow, busier than a one-armed banjo player, this episode Jon😅
It's good to see things getting sorted, toe rails turning out nice mate. Merry Xmas to you and your family as well.
Thanks! Merry Christmas to you as well!
Is it possible the black layer under the paint was a coal tar epoxy barrier coat? Did you determine what and how the animal was getting in? Isn't it more common place to start with the smallest patches and work out to the largest ones? That way you have only one edge showing when you are done. It makes a smoother patch all the way cross with all the other edges underneath the last layer. For your regular vacuum hose, could you insert a funnel into it to broaden the area of suction coverage? Do you intend to wrap fiberglass strips over the top of the bulwark once it's filled? I don't remember seeing one originally.
Hi! Lots of good Qs here: the patch order is heavily debated. Marine experts (from my research) tend to recommend largest first. One reason being that IF there is any material knocked back during fairing, it is your smallest, least structural patch. You also get the largest overall bond with largest first. Epoxy is so strong and sticky that it probably doesn’t REALLY make a difference 🤔. For the vacuum, the breather acts as a distributor for the pressure. And yes! Planning to wrap the bulwark cap when it’s dry/rebuilt! 🙏👍🙌
You would probably think so but the geneal school of thought is largest patch agains the hull for the best surface area bonding. Ive seen it done both ways but i think this is the generally accepted best method, but i agree it foes seem counter intuitive
I will also agree that it seems counterintuitive. This is the method that my research has landed me on…
I think either way would be fine if properly prepped and rolled out for voids.
Epoxy will be your friend for a repair like this. 👍🙌
The main reason none of this matters is epoxy is a glue and a laminating resin. I always liked small to large as it left one with less hairy edges to grind and fill .
@@10marlie That's a good way to look at it!
Nice f800 GSA! I also use the Fein tool for the many jobs around the house. 😊
I watched “the long way around” when it came out about 20 years ago and always wanted a BMW ADV bike after that! Haha. It’s a pretty fun machine! Gotta love the Fein tool also. You’ve gotta love the German engineering! 👍🙌
@livingforsail well, I'm German and I love good stuff. Sadly we are forced to produce to a lower price point nowadays. Chinese competition doesn't have a positive impact on quality.
@@gerritsamson It's a sad reality of the times... I spent some time in the south of Germany about ten years ago and had such an amazing time.
@@livingforsail yeah, very challenging times. Chinese competition, Putin's war, and tariffs in sight...many things have changed and many more will. Anyhow, I wish you success with your project!
@@gerritsamson All the best to you as well.
I don’t think I’ve seen many thruhaul repairs done to this high standard. I don’t doubt your research/approach at all. (but it would be interesting to know the incidence of failure in those lesser jobs) perhaps they arrived at Davie jones locker never to be heard from again 🤷♂️
Haha. Let’s hope not!
I know the Gougeon brothers say that, but had you went with 5 inches wide, it would have been more than enough, specially if you reinforce it from the inside.
I wouldve kept away from the stem for that is such a strong section of the boat. some things are best left undisturbed , to my view.
Thanks for the feedback 🙏
Very little material was removed from the stem area but I appreciate your point. 👍
That scarf seemed excessive for the size of that hole.
@@dennisdavidek6694 Maybe so. How about "Better safe than sorry"?
Your paint looks like an old paint system i applied many years ago, about=1978. It was a system a adhesive layer, 5 or 6 coats of epoxy tar and then again a adhesive layer between the antifoul. It was from Sikkens, the Netherlands. Later sikkens was into the AKZO NOBEL group.
Interesting, I've just commented on this stuff too. I never knew what it was. 1978 would have been about the time it was applied to by boat. Thanks for the info.
There you go! Interesting! For what it’s worth, the laminate was essentially bone dry when I finished cutting that bevel. Good stuff I guess. 🙏👍🙌
i would suggest using a heat lamp. for that size you would need a multiple bulb fixture. It will eliminate the necessity to heat the entire shop to the required temp for proper curing of the epoxy
That’s what I did 👍
Greetings from New Zealand, look grinding all that paint off is easy and the New Zealand Navy just did it to their only very expensive survey ship ... you just run it onto rocks and burn the paint off ... well that's how the Real Professionals do it and Kiwis are the best boat builders in the world so ... we'd Know ... so long as no one gets killed and keep saying how amazing it was that no one died
Haha! As I like to say… “there has to be a harder way?!”
👍
Hi I like your clear engineering approach however I think you might like to consider an alternative that you may not be aware off? Dust has always been a major issue with glass however it can be completely mitigated by the simply addition of water! Wet sand and you will never look back and of course you can always use a diamond planer instead of a sander. Just saying….. been around glass boat and cars for over 40 years!
Cheers!
Ian
Hi. Thank you 🙏. I’m always interested in new ideas and other ways to look at things. I’m not a pro here and have much to learn. I’m grateful for these constructive tips.
That must make quite a “slurry” of glass paste. Do you just towel it up and dispose? What kind of sander do you use for that?
Cheers.
I would suspect that the last layer you were sanding and found to be difficult was an epoxy barrier coat which is applied over entire hull to prevent blistering.
Thanks! 🙏
something to think about when fixing her up is if you would like to install a bow thruster ???
Ding Ding. We have a winner! That’s why I’m patching this up now… making room for a thruster tunnel! 😉
@@livingforsail NICE will help with docking and with your prop setup👍👍👍👍👍👍
Or would a drop down like Amials have be better?
@@jackdbur Those are very cool. And Expensive...
@@jason4109 Yeah, She is especially unpleasant in reverse with very pronounced prop walk... a thruster will be very nice to have.
I’ve had good luck with bottom paint stripper. It’s pretty mild as paint stripper goes, certainly needs a little ppe but not like the old style old stuff for removing all paint. Just apply and then immediately cover the stripper with plastic sheet so it doesn’t dry out.
That kid for the tip. Cheers! 🙌
As for the Black layer on the hull; I had a tar or tar like layer below my antifoul, it was there from a long time ago; 30+ years. The antifoul never adhered to it well and last winter I had my hull blasted down to the gelcoat, blasting had no problem with the black tar coat. The blasting remove some gelcoat, but I think it was only removing the 'bad' gelcoat. The hull is GRP layed up in the 70's. I think the basting was the best thing for me. It exposed the bad gelcoat that then needed filling and an epoxy sealing coat, but I happy it was done and the repair will last a long time.
I think that sounds good. I might opt to do that on the way back to the water when we are at the yard. I think trying to blast inside the shed will be a HUGE mess! Haha.
when doing a repair like that I prefer to grind bevels inside and outside. That way the depth you are grinding to is decreased and the bevel width is less. In other words, if your hull is 0.75" thick and you grind half way through (0.375") the 12:1 bevel only needs to be 4.5" wide. Grinding bevels inside and outside will result in you doing half as much grinding. Also you will be getting new chemical bonds in the center of your repair when you lay up glass on both the outside and inside of the hull. Another option is to do a cored repair where you insert a piece of core material and then put a glass skin inside and outside. Use a closed cell core material such as divinycell foam. Alternatively you could use a piece of G10 epoxy glass sheet for your core. If you do that your glass skins require a much smaller bevel width since they will be thinner.
Interesting idea using a core. Thanks 🙏
Hello I’ve been working with West system for 20 years on my three last boats and your right! in theory the 12 to 1 bevel is what is recommended by the Gougeon brothers. But since your boat was overbuild like most boat from the 70 early 80 you could of gone with a much smaller bevel (6 or 8 to 1)that would of been as strong. Also I’ve been thinking all those years about the small to big or big to small dilemma and personally I think there is advantage and disadvantage on both technics
so my last holes that I’ve fill, I do : big to small the first half of the way and I finish it up with the small to big layering.
The last two layers I will use mat fiberglass to ease the sanding. Also even if the styrene that bond the mat together is not dissolve by the epoxy, since it’s a pretty flat surface at this point , it doesn’t really matter if the mat stays stiff.
I’m filled with anticipation to see how you are going to apply those giant first layers… maybe I would consider layering them on a piece of mica and then tape and vacuum them to the hole .
I like the idea of the “hybrid” approach. The CSM final layers makes sense too. I put the first layers on at the end of the video… cheers! 👍
That dark layer is an indicator layer, likely with graphite powder in it. It is tougher to scratch through so it can show you when you've breached your gelcoat on a scratch/gouge.
Thanks for the info. Much appreciated 🙏👍
As far as grinding the hull goes, the more aggressively you cut the glass the must dust you get. Aggressive make big chunks which do not get airborne. Do the rough cut with the concrete grinder and then a small shallow cut to clean up the gouges.
Those concrete diamond surfacing cups come in up to 6inch with appropriate shrouds available FYI.
Yeah, that seems to be the way that it worked out in the end and what I will do starting out next time! 👍🙌🙏
Good tip. Thanks!
More progress.
Merry Christmas 🎄
And to you as well! 🙏🙌
Merry Christmas all.
Yes! Merry Christmas!
Great vídeo
Please which brand is you beauty green Antifouling???
I wish I knew… I love the color. If I turn up an old document in the pile I will update in a future video 👍
i am surprised you started by installing the bigest layers of fiberglass instead of the smallest.. is that optional or I ve always been wrong?
This is a BIG debate…. You can check the comments for both sides of the story. Either way will get the job done. Using epoxy is going to be a step that will help ensure a good result.
I think it’s a bit counterintuitive, but for marine applications most experts recommend the largest patch first and that drive my decision.
👍🙌
When I stripped my hull down to its original barrier coat, I used a four edged hand scraper. I found that when it was very sharp, I could pull one blade width of bottom paint for a full length of my stroke down to the base material in one swipe. I would get about 5-6 swipes per edge and then rotate to the next edge. After all four edges had been used, I would use my Dremal to retouch all of the edges and continue on. It was much faster than sanding and much cleaner than sanding or stripping. It left chunks of paint rather than dust or toxic goo.
I’ve had a few votes for a good scraper. I’ll have to give that a try! Thanks!! 🙏 👍🙌
Hi! The black color may be some kind of epoxy protection that was used before. I have the same material on a 70's motorsailer in Sweden
Interesting. I didn’t think they had epoxy until much later but Antidote was built in ‘89 so… 🤔
@@livingforsail Hi! It is possible that my boat was treated with that material much later. I have owned the boat since 2011.
@@dimitri1660 Well thanks for chiming in either way! Cheers.
I used homemade dust collection both at the source and from the air. I wish I had Doors in both sides but only one. Collection from the air is critical.
Yeah, keeping the dust contained is a big priority for me.
you start with the smallest circle of fiberglass and then you put a bigger and bigger circle on it. and you do that on both sides of the hull
That’s certainly one way to do it 👍
Next time tie a bungee cord to the sander and to a stanchion or toe rail. Let the bungee cord take the weight of the sander/grinder.
💯
Oh, that is WAY TOO smart! Cheat code unlocked!! I can’t wait to try that! 🙏👍🙌
Small to big. The way it's done here, only the first layer has a mechanical bond and all subsequent layers function as filler only. You want each layer to have a structural/mechanical bond to the parent material(hull). Fixing a fuselage in an modern aircraft using the method shown here, they'll charge you with a murder attempt.. 😉🙂
Aerospace runs small to large. Marine runs large to small. This again according to the experts I’ve talked to and no one needs to be charged with anything 👍😉
I'm assuming the plywood in the bulwarks was just filler, not for significant strength. Why not just refill with epoxy mixed with high strength filler like West 404 and maybe some chopped up fiberglass?
This boat has a funky hull to deck joint and I think I’ll sleep better with something a bit more stout in there but yes, it seems that much of the bulwark was just “filler”… also we have bulwark mounted stanchions, so I need strength there. 👍🙌
I think your calculations are off for your patch, 12:1 is correct, but you should be doing it from both sides (assuming you can get to the back side) which really means that as you are attacking it from both sides, the taper you need is effectively for half the hull thickness, or a 4.5 inch taper on both sides, which makes for a 10 or 11 inch diameter patch.
No expert here but tend to agree, tring to basicly make a fiberglass rivet.
These are good points but I believe 12:1 is most common with many other scarf joints too -- this just happens to be a circular scarf. Most wooden aircraft wing spar repairs are required to have a 12:1 scarf joint to be considered airworthy. And even though we can find boatbuilders using 6:1 to build plywood-only dinghies, most butt-block replacements in wooden-planked boats are retroactively fitted with two-foot-long, double-ended scarf patches that closely resemble (in a linear manner) the type used for Jon's thruhull removal fiberglass patch (in circular shape). Both Aladino and Andy confirmed that a single-sided repair provides the necessary strength, so I'd go with those sources. It's a lot to visualize so feel free to pick apart my wordy explanations and I will try to find more references.
It is worth noting that the fresh backing plate that Jon installed is also chemically bonded to the new, outer patch because he installed the outer glass while the innter backing plate resin was still green/tacky. So his outer patch is now, also chemically bonded to the inner hull surface in rivet fashion with that backing plate. Wooden scarfs (scarves?) are slightly different in that they benefit from stronger glue bonds than the purely mechanical bonding of a new-to-old glass-to-glass joint. So a 12:1 fiberglass scarf gives you the needed mechanical strength when going from old-to-new glass.
Check out the channel called Building Temptress for some more examples of 12:1 scarf joints -- Dan Lee is amazing.
@@scottcates I agree, I didn't say anything in my response about changing the taper ratio. Its still 12:1 the only difference is because you are doing the patch from both sides (as you're supposed to) you are effectively trading the hull is if its half the true depth. otherwise all you are doing is grinding away the patch you just made!
Just saying that because of the way he choose to make the patch, the ground area is way larger than it could have been under normal circumstances.
Doing it from both sides is a good approach. I probably could have pulled that off but it’s very cramped in the bow and I felt a could get the bevel better from one side. The experts I talked to said with a 12:1 bevel and good prep, nothing to worry about 👍🙌
It’s a good approach no doubt 👍
Interesting using West System guidance (the undisputed experts) but Seahawk products.
The West System manual should be fine to use with any similar 5:1 epoxy 👍
Awsome stuff! Love the details you provide in your video's. Your transitions are cool as well. And your edits are great!! Can't wait to start my own sailboat build ( check out the "polar 44 sailboat") not fiberglass, but still a massive project.
Thank you for the feedback! All the best with your project too!! 🙏👍
The Black stuff is VC Tar, an epoxy tar barrier coat popular in the 80s. No longer available.
Thank you. I’ll look into that. Cheers!
A dumb question maybe, but why not simply put a SS or bronze plug in the hole? This fiberglass job is huge.
Yeah, it’s a big job but I’m happy to go for it. I’ve not heard anything f a long term plug repair but that’s an interesting idea… 🤔
For the bulwarks can't you just vacuum bag it and "boil" out the moisture with the vacuum pump?
Thought about it… too many leak paths to get a decent vacuum… you need to be Into the micron range over 29”HG to get a boil at ambient temps…
Good thinking though. 👍
I know absolutely nothing about fiberglass but I'm certain you should have started with the small circles and then gradually get bigger
This is maybe my favorite comment so far… 😀
@@livingforsailHa!
CSM bonds better as base layer,however you make a good point regarding fairing but remember if your grinding into biax cloth or chop in the process of fairing your lamination is wrong, not wrong in the way it’s no good at all. You should never go into any laminated cloth or chop when fairing. When your lamination is at the level required always make sure you can fill the weave and some. Some pros will use gel coat with micro balls to fill the weave on the first stage of fairing to insure they are not in any way cutting into the freshly laid material. However using a layer of chop as a last laminate as a sacrificial layer of sorts is a good safety barrier. You have gone to the trouble of following a suggested method I would lean to the advise from the individual who gave you that. Good point to raise and probably not considered at the start by many amateurs. Remember chop has next to no strength really it seals and seems to work very well as primary bond surface, better than the weaved cloth, so thinking it could matter on a repair that’s smaller and is under a lot of flex and twist forces. Some paper somewhere will have a detailed explanation on who goes first and why, I say it would be variable pending a lot of different factors.
Thanks for the feedback 🙏👍
CSM as a base layer stems from polyester (maybe also vinylester) repairs. It is not a factor in composite repair utilizing epoxy resins. This is true for marine and aerospace composite repair applications. I do like the idea of CSM as a sacrificial sanding layer and have implemented it in my "toy" sailboat.
@@projectseahorsesailing I have read that some say it helps bond layers because of the short fibers that "claw" into the substrates. I was told by West Systems that mixing in some micro fibers helps to improve the bond between old substrate and new laminates.
@@livingforsail Interesting, I was mistaken then. I was under the impression that it was only necessary for polyester. If West Systems says it improves the bond in epoxy as well, I believe it. Thanks
A paint scraper might work in some cases.
That’s a few votes now for the good old scraper. 🙌
Hey new subscriber here. Can you tell me what type of sand disc and grind disc you are using please. Got a similar job coming up! Thx.
I put most of that stuff with links in the description. Let me know if something is missing and I can certainly let you know. Welcome, and good luck with the future repairs! 🙏👍
@@livingforsail ah on mobile so missed the detailed description. Will take a look thanks.
@@timdhines Email address is there too if I missed something. Happy to help.
An electric household dehumidifier may help the condensation
Good tip! Thanks!
Looks like GRP + epoxy layer coat + primer + gelcoat to me, the dark stuff being the epoxy coat.
That could be. It might have had a more modern bottom job at some point. Cheers. 👍🙏🙌
Are you sure it wasn't supposed to be 12" diameter instead of 12" radius? That taper seems excessive, especially that close to the bow.
12:1 scarf for a structural repair. I could have made two smaller circles if I did it from both sides.
Doesn't the ratio relate to the diameter of the hole, not the thickness?
The 12:1 ratio refers to ratio of the scarf width (per side) relative to the thickness. So in this case, the “1” is the thickness of the hull (0.75”) and so each side of the scarf is 9” plus the width of the original hole (~2”) ends up with a nearly 20” repair patch.
Taking the scarf from inside AND outside would have effectively cut the patch size in half (and is a good idea if possible) 👍
You shouldn't even worry about taking moisture readings until you've fully removed all sources of wet core. More important than temp is low humidity, get the air in the shed and inside the hull as dry as possible. Try a diesel or kerosene heater, an electric one will be way too expensive on your power bill. I don't know what the moisture readings are on your bottom, but it's safe to assume all older polyester boats are wet. Before you worry about any other repairs, you should strip the bottom paint completely and continue hunting down wet core every where else until it's gone. Sorry to say, grinding out the bevel from the old seacock was fine, but putting on the epoxy patch should have waited until you confirm the laminate isn't wet (however that thinner glass at the bow is unlikely to have retained moisture, so you're probably ok).
Also, I hate to say it... because I have mad respect for WEST as a company... but you can't take everything they advise as gospel! A 12:1 scarf was massive overkill on that small seacock hole. A 12:1 scarf is for wood which mostly consists of uni-directional fiber orientation with vastly different properties... Fiberglass does not mechanically behave like wood! Also, that area of the bow is, by nature, much more structurally robust than other parts of the boat's bottom. Based on the thickness of the laminate and the area that its in, a 6:1 scarf would have been more than adequate. Remember, this is modern glass weaves, epoxy, and vac-bagged... the properties are vastly improved over the boat's original hand-laid polyester or chopper gun application. Small to big on the outside patches, last layer should be a should be a thin CSM or you going have print-through (not a big deal on the bottom but better learn the lesson here than anywhere on the top sides). If I was doing a critical structural repair like a mainsheet track base on the cabin top, yeah I'd go 12:1... not for thru-hole repairs (and I've done a few).
Thanks for the feedback. I meant to include a segment about checking that patch area for moisture before proceeding. I was going to pull it down with vacuum and a heat lamp to help dry it if needed but it was bone dry! The moisture meter didn’t budge off of 0%… there is a person that has reached out to let me know or that they were in the yards back when they built the late 80s hulls and apparently used vinyl ester so that may be part of the credit for the dry repair area. 👍
@@livingforsail It was not at all common to use V.E. resin on production sailboats until the late 90's and even then it was only semi-custom and premium brands, they would typically only use the V.E. resin on the first laminations in the mold and then switch back to polyester. I'm not saying it isn't possible, but if they used any V.E. resin in your lay-up then you should find very few or no blisters and little retained hull moisture in the laminate. Fingers crossed this is true... When you replace the core in the bulwarks I hope you consider using Coosa board or a core foam. Avoid using any plywood, anywhere, of any reason.
@@SteelDoesMyWill Thanks for the info. There were few blisters on the hull. More paint removal will tell how the condition is... I am using some coosa and diab foam for the deck and have a few videos about that. I replaced a forward bulkhead with marine ply and went to great lengths to seal it with glass and epoxy. After all of that work I can safely say that I would 100% use Coosa for ANY ply replacement from now on.. it was a cost thing that probably was more expensive in the end... live and learn...
@@livingforsail I watched your deck video.. nice choice with the H100 and then Coosa in the middle for forestay + anchor windlass strength. One tip, don't roll raw resin onto the foam, only use a thickened resin for that. You'd be amazed at how much epoxy that foam will absorb. Because you had the two deck skins and applied clamping force I doubt you'd have issues with adhesion, but you'd have gotten away with far less epoxy overall if was a fluffy with 406.
Just curious, why didn't you just replace what was originally in the hole?
I’m not sure I understand. I don’t have the original core from that hole. It was drilled 35 years ago in Taiwan. This effectively did replace what was there before (fiberglass) and the tapered scarf is needed to get a good mechanical bond.
I'm no expert but I'd a stuck a coosa board plug in that hole with epoxy and a backer inside. Lord that was a lot a work for a through hull fitting. Leave the fitting in there LOL
Thanks for the feedback! 👍
12 to 1 on that little hole is way beyond what's necessary. A 45 deg bevel would have been sufficient with a flat cloth patch on the inside, colloidal silica in the hole and slightly dished patch on the outside. Gross misunderstanding of patching a small hole.
I followed the guide laid out by west system. I am inclined to take their advice but thanks for the feedback 👍
@@livingforsail I can tell you from experience that what you're doing is way more than necessary, The load on that hole is insignificant at the depth of water that it sees. Assuming that the hole is three feet below the average water line in that area and that the hole is 2 inches in diameter which gives a hole area of 3.14 sq.inches and a water pressure (at that depth) of 19.6 psi, the total pressure on the hole would be 61.5 lbs. You could plug that exactly as I've described above and you would have no problems. On the other hand if the hole was 12 inches in diameter you would be dealing with an area of 113 sq inches and a total pressure on the hole of approximately 2217 lbs. That would be a different story and the 12:1 taper would be more appropriate...so I guess you can say you got a lot of sanding practice. You might want to look into learning some basic principles of hydrostatics.🐬👍
I made a mistake. The actual pressure on the hull is the difference between the water pressure on the outside and the air pressure on the inside. That's a total pressure on the outside pushing in of 4.psi which makes the actual force on the 2 inch hole even less. That's 13.2 lbs total on the 2" hole and for the 12" hole it would be 474.6 lbs. Still the same repair result. That's my final answer and I'm sticking to it. 🐬👍😂
@@ChrisTietjen_00 I think you might want to factor in more than just water pressure... It's the bow of the boat so I do want it to be strong and... again... this is what some experts recommended. I'm not looking for bare minimums here :)
@@livingforsail It's just the extra time you spend sanding and it's your peace of mind so have at it and go sailing!
I thought they started with a white gel coat before switching to bit of black to avoid any blotchy see-through in the white 🤷🏻
Oh. That would make sense… 🤔 thanks!
Required bevel depends on the laminate underneath and only applies you you want to achieve original strength in the structure.
According to the book we had in university, the minimum bevel for glass repairs (to achieve original strength) was
1:5 for chopped strand
1:10 for somewhat balanced fabric laminates
1:20 for UD laminate
Then again, if you already had a 2" hole in there would you really need 1:10+ bevels? That is not really 'fixing' the laminate, rather you are just filling a hole and only requirement is for the patch to plug the hole and stay in place. Sure, fixing it properly is always better and leaves more options to drill new holes in the future without worrying about laminate strength.
Bahco 665 scraper with diy vacuum attachment for bottom paint removal. Took me about 3.5 hours to scrape 50+kg (110lbs) of bottom paint (44years worth) from my HR352. Sure, there was ten(s) of hours fine cleaning with 6" orbital after that, but good quality scraper is the clear winner.
The quality difference in paint scrapers is ludicrous. Even some 'good quality' scrapers are just useless.
Thanks for the feedback and for the scraper tip. I’ll check it out! 🙏👍
I'm not an expert in fiberglass so please excuse the ignorance, but the order of the layers you're putting on seems back to front to me. Shouldn't the smallest piece be first against the hull, and then as you build up the layers the pieces become progressively larger, so that when the patch is done the largest piece covers all the preceding layers? The way you're doing it now there is only one piece of glass bonded to the hull, but if you do it from small to large the edge of every layer would be bonded to the hull. Wouldn't it be a stronger patch then?
This is a super relevant question and that assumption makes a fair amount of intuitive sense to me, too. In the world of fiberglass repairs, the experts that I've studied teach that either "direction" is adequately and strongly bonded. Small-to-Big or Big-to-Small seems to make no structural difference. But, yeah, it seems like a larger, outward layer would yield a flatter, smoother surface. Maybe the peel-ply-and-vacuum method keeps it all super flat as layers build up? I've never used vacuum or peel ply so I really don't know but everything I've studied seems to indicate it.
You can do it either way but this is an area where some people have strong feelings. If you are one of those people do it the way that makes you happy.
th-cam.com/video/yiLQnfOvI3w/w-d-xo.htmlsi=zFF0Zm7MKF-_mVcR&t=996
Big piece first so it has maximum bond area. If you start with a small piece, each piece has a small bond area onto original laminate. Also, you typically grind-off the bump in the middle, making a hole in the biggest pieces.
@@scottcates Thank you for the link. I enjoy listening to varying opinions.
🙋 Слава Рукастым!!!✊
🙏👍🙌
I love your choices of background music.
Thanks! I know I can’t make everyone happy with the music. I appreciate the feedback. 🙏🙌👍
Jez your making a mountain out of a mole hill
Thanks for the feedback
@@livingforsail, I love your responses!
This is why my Wife has banned me from buying a boat that needs work. I am not in shape enough to tackle it. So looking at CSY boats.
That’s a good plan 👍
Probably barrier coat
Good call.
Great review of tools... but way overkill on the amount of taper. 2 inch on both sides of hole with a little Coosa plug would have worked. And epoxy only.
👍
la partie noire qui apparaît au ponçage sous la peinture sous-marine (antifouling) est probablement un époxy brai destiné à protéger de l'osmose.
Merci 🙏👍
I have never seen anyone sand before grinding. Really.
I was looking for a way to get the anti-foul off and Into my dustbin and not all around the shed. Knowing what I know now I’ll probably reach straight for the concrete diamond wheel and get both birds with one stone.
@@livingforsailwhy not use a grinder thin diamond cutting blade to cut the gunwales. They even have vacuum shrouds for them. 😊
@@jackdbur That could be something cool to try. I have a one sided shroud that swings partially out of the way that would probably pick up some of the dust and be MUCH faster... Something to think about. Thanks.
Le contre plaqué ce sont des renforts
Merci! 👍
That is way overboard for such a small hull repair. A 2” hole only needs a total of 8” circle back gouged into the glass. Of course west system is going to tell you to go way way too big. That means they sell more resins. If you can’t see that you are thinking !!
It’s a conspiracy! 👍
Laisse tomber la gangrène du polyester c ingérable l’humidité est installé dans les couches entre mat et roving à la construction 😢
Let’s see if my grade 9 level french holds up… Je ne comprende pas… ?
Wonder if all your neighbors signed on to you placing a boat yard in your driveway. I would not be so understanding…..
I have great neighbors 👍
Total overkill on the hole patch
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Um Gottes Willen, du schleifst ja den ganzen Rumpf kaputt. Innen und außen ca. 3 cm anschäften und von beiden Seiten geichzeitig nass in nass laminieren. Hält ewig und man hat nur eine kleine Repatarurstelle. So habe ich Borddurchbrüche (Toilette, Logge usw.) verschlossen und hält nun schon 15 Jahre!
Thanks for sharing 🙏
wow … what a complete overkill and WOFTAM to plug 1 small hole and if you’re going to spend that much time over such a small hole you’ll never get to sail the boat. A piece of fibre board cut to fit with a slight taper and strong epoxy glue it in. Sanded down both sides and primed. 2 hour job tops.
You’re hired!
@@livingforsailHaha.
Music is annoying when watching in the early morning. No music would be better. Just explanations and procedures.
Maybe watch later in the day? 🤷♂️
@@livingforsaillol.
I used one coat of acid & then with a floor cleaner with a about 15cm hand scraper got my boat down to gel coat. It a Fisher 25 😎& I forgot to say, Im a disabled sailor wheels on land 🧑🏽🦽➡️the boat on the water. 😄
Nice. Thanks for the tips.
I am generally curious how you make it work as a disabled sailor on the boat. All lines led aft? If you need to go forward?
T-peel strength is dog shit in epoxies, you are correct to use a very large patch.
Thanks.
👎👎👎👎👎👎
🤷♂️
@@livingforsail polyether resin ?
@@user-tf6ny2kp9mmoon Never heard of her.
@@scottcates What kind of resin is this?? is it epoxy or polyester resin?
@@user-tf6ny2kp9mmoon The boat guy, Jon, mentioned epoxy a few times in the comments here. So, maybe epoxy for the increased bond strength? What's the difference in your experience?