Lap Sealant Isn't Necessary! There is a Better Way of Sealing RV Rooftop Attachments
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- เผยแพร่เมื่อ 10 ก.ย. 2024
- This video is a step by step illustration of how to avoid unnecessary lap sealant when installing and sealing a new skylight dome on the rooftop of a Beaver motorhome. A sound explanation is provided as to how lap sealant compromises your ability to inspect and assess what is really happening under this unnecessary goop and forms a less effective seal than the technique used in this video. Hopefully, you will never want to use lap sealant again after watching this video.
#sealingrvskylight
#lapsealant
#dicor
#sikaflex
#rvmaintenance
#rvroofmaintenance
I owned a sailboat for decades before I purchased my motorhome. I could not believe the crap products in the RV industry. I tell everyone I meet to stop using self levelling sealants and use 3M 5200 marine caulking/adhesive instead. You won’t be doing it every year. I haven’t had to replace mine in 12 years.
There you go! Thank you, I don't feel so alone anymore. My RV supply store is our local marine shop in our small town. I re-bedded our sailboat stanchions in 2003 and all deck hardware in 2006 and everything continues to hold solid to this day. I cringe a bit whenever I use 5200, knowing that it's going on forever, but you're right, you won't be doing it often. I think 5200 is a great product for redoing the nose and rear caps on rigs, where these fibreglass cones meet the main body of the RV. That's a very important joint and I'd feel a lot better with 5200 in there than whatever the factory used, covered by lap sealant. Perhaps we'll pass by each other one day in a marine supply store! Thanks for watching the video and offering your comment.
Is it self levelling also?
@@JohnCarter-r2g On a warm day it is self levelling. It is more of a permanent solution that I used on my solar panel mounts and front/rear caps. I also used Eternabond over all vent frames and front/rear caps with a small bead of 3M 5200 along the Eternabond edges. Some will poopoo Eternabond because it is so difficult to remove, but 14 years later my Eternabond is still doing the job with zero maintenance.
I am not only referring to the poor caulking choices, most of the hardware is plastic crap that will break in a couple years and need to be replaced with more crap. Just offer us stainless steel parts at more cost, better than throwing away parts every couple years.
Thanks for saying this. I completely agree with you.
Brother, you absolutely nailed this. Dicor Lap Sealant is the dumbest idea. Their motto is "bigger the glob, better the job". They put so much sealant that is does cause a water dam and prone the water damage.
That Marine sealant works wonders. I have a few things to correct on my roof. I plan to use the Marine sealant like you did.
Thank you for sharing.
Oh that's funny, I have never heard of that motto. Thanks for being so supportive of this technique and type of sealant. I really do believe in using only marine grade sealant and other types of marine fittings when possible on our RV. And the water dam effect you mention was sure real in our case. It was like a swimming pool. Thanks for being a believer and getting rid of this Dicor stuff. And good luck when you fix those things on your roof. Cheers!
I use a dewalt multi oscillating tool with a wide scraper blade.
Works great.
I've worked on rvs for over 20 years.
Dicor makes the roofing material and the sealant. It's a good product when used properly.
It's work no matter what. Good job.
I've never used the oscillating tool. Must give that a try next time, thanks for the tip. I respect what you're saying about Dicor, and your experience with working on rvs. I wish I had shares in that company! I appreciate you watching this video, and commenting. Thanks!
Please take a note, this method works well for the application he is using it for...that is to say, he is using this sealant on a fiberglass roof and his method makes sense here. If you have a membrane style roof, especially a Dicor roof material with the longer warranty, take the time to read your warranty since it will tell you that you they highly recommend using Dicor roof cleaner, sealant and lap sealant to maintain your roof EACH year to not void your warranty (keep recpts). It is also explicitly recommended to NOT use silicon or latex caulk since it may damage the rubber membrane and will not adhere properly. I have a 10 year warranty on my roof, so I use the Dicor products and they have worked just fine. As far as the lap sealant, I remove the sealant that is in place every other year and the reapply. The older sealant tends to get dirty and the new sealant will not stick to it correctly....I do clean the sealant when I do reapply and over-seal, but I find after to years it is too hard to clean and it shrinks. This sealant removal also keeps down the water retention issues that constant reapplication without sealant removal tends to happen.
To that note I have also seen people use Permabond Tape with great success too. A lot of the Skoolie crowd uses this and they get years of adhesion and positive sealing. Fellow RV'er resealed his older travel trailer with a TPM roof 3 years ago and he has had no issues.
Great video and a great discussion!
I am grateful to you for having the interest and knowledge, and taking the time to offer this clarification and other options. I did not emphasize enough in my video that the method I used is solely for fibreglass roofs - and many RVs have different roof construction. I suspect I may have left many people hanging, wondering about their particular situation. Your words are better than a video! Thank you for chiming in this way.
Nice work. Another great sealant is Dow 795 because it sticks extremely well to anything. Most People don't know about it because it's a commercial sealant with a high flexibility and an incredible stretch factor. The flex factor is awesome on an RV due to the constant movement while driving.
Thanks for your kind comment and for telling me (and our viewers) about this Dow product. I love learning about new supplies to use, recommended by others who have tried them. I too like the flex factor. I will look for this one. Thank you!
Just because there is a mass market product made for a job doesn’t mean it’s the right way to do it. I also hate the look of Dicor type sealants. So many videos of people slathering it all over their roofs, it looks so bad. Ive been waiting for video like this, thank you!
In a few concise sentences you have neatly summarized what I was feeling making this video. Thank you! I was a bit hesitant putting myself "out there" with this idea that frustrated me, thinking who am I to take on an industry practice that people seem to follow without question. But I jumped in and now, you've made me feel it's all worthwhile. I really appreciate you for telling me this. All the best!
Just found your channel. I love your channel name...very creative play on This Old House. We have a 24 year old Class C motorhome. Making improvements like this are essential for RVs with some age on them. There is so much information on You Tube that it is getting much harder to find quality content. Thanks so much.
I'm really glad you found us. It's kind of you to write to us to let us know. And you nailed the name, that's exactly where our name came from. I love it when people maintain older RV's (and older cars) and there are so many things we can do to keep them in good shape. I hope you stay with us and that you keep enjoying your older Class C. It's probably better built than the new ones today. All the best, and thanks again for your comment.
Great Teaching Video! Thanks for sharing your expertise with us! Nice to know that DICOR isn't the only option!
Hi again, I'm happy you were watching this video and found it useful. I know I rambled on more than I should have, but I was hoping to accomplish just what you mentioned - a step by step process so others may learn. It's not a perfect process, we all have our own way of doing things, but it's something I'm comfortable with and wanted to share. You've made my day, thanks!
There is an even better way to do this and it will be much easier to replace the dome in the future. You don't want to GLUE it to the roof. Use PUTTY TAPE. Not butyl but you can use that too. Butyl Tape is great but messy. PUTTY tape is a drier form of the same thing and will last for years before replacement is needed. Up to 15 year or more. It will seal the best and not glue the dome to to the roof. We use this for Vintage Trailers all the time. It is time tested and has been used for almost 70 years.
Thank you for telling me and others about this, it sounds like a great technique and I suspect you know what you're talking about. And you're right, the way I did it does bond it to the roof and a bit of a chore to remove. I'm always looking for better ways of doing things and I'm taking special notice of what you're saying. I have no experience with butyl or putty tape, I guess it's time. All the best, thanks again.
As usual, great video Bill. Informative and entertaining.
Thanks, Bruce! I particularly like the backdrop, something I believe you have something to do with! Thank you for everything you do to support us working on Monty. And being my break buddy!
It's great that you use previous knowledge of marine skills for Rv applications. I'll have to remember to search outside the box for solutions! 😊
I'm hoping you now have your Roadtrek - wasn't it last week that you were picking it up? You must be very excited! Now all the fun begins, and new adventures. You're going to become a pro at maintaining your new rig. 2002 was a good era for well built RV's, and Roadtrek is one of the best. Have fun, and please let me know if you ever want to talk about something to do with your rig. Happy to help. email: cryslerpacific@outlook.com
@@ThisOldRV2023 I will gladly reach out to you if I have a problem I can't solve! There was a hold up getting insurance card to the notary, so I'm actually picking it up today!!! Yes it's exciting, but I won't be ready to make more than short trips till next fall. Take care ❣️
I'm very happy for you! Enjoy every moment, it's an exciting day!
Great video. Thanks!
After 50 years with many boats, bikes, and 55+ cars/ trucks I'm finally in the RV game, buying a 2011 trailer last year.
I was totally following along until you dumped out the bag of screws and washers. I was thinking "what's going to seal those? Water will follow them in. Hasn't he heard of "metal roofing screws" with their captive synthetic-rubber washers, designed to last decades in the sun?
But then I thought about their small diameter, and how steel can deform under pressure without losing strength, whereas polycarbonate, like glass, handles stress by cracking. Hence the "fender washers" that you used to distribute the force over a larger area.
And then I read you explaination in the response to @chrisholds1 below, when he asked the question that I was thinking: how are you sealing the screw holes?
Your explaination was detailed and excellent, and as an engineer and designer, I think it perfectly addresses both the immediate issue of sealing, and the longer term issue of inspection.
Though you didn't explain the details of "why" in your attachment process in the video, I know that there are challenges with video length, the longer the video is then the fewer watch it, etc. and I don't have any suggestions for how to handle that. Sorry.
I'm thinking that you could have a web-page that covers these things in more detail, and embeds the TH-cam videos, and ideally would be monetized in some way but that's more work, too ... (mentally rambling off-topic).
Thanks again for the great info and tips on better products.
And also Thanks to all the commenters with more tips!
And maybe I'll see you some day when we're riding through Ladysmith and stop for coffee. :)
I enjoyed reading your remarks and appreciate you for making them. And I can sure understand why you were a bit stunned when you saw how I was using the screws and washers, wondering about sealing them. My biggest regret with that video was exactly what you're pointing out - not explaining why I was doing it that way and what I expected to achieve with the seal. As you would know with your boat experience, I was using my past 25 years of keeping our sailboat "dry" using this same technique. But I can't expect others to believe this if I don't explain myself - it naturally invites uncertainty. To know you are an engineer and designer and it makes sense to you, means a lot to me. Thank you for following it through to try to understand what I was doing. Your idea of a web-page to cover topics in more detail is intriguing. Thanks for the tip, I will remember this.
Another person mentioned metal roofing screws as well, of which I'm not aware. I like the idea of the captive synthetic -rubber washer. I guess I was just following what I've always done on my sailboat. I agree that the smaller diameter may be a problem.
Thanks again for having the interest and taking the time to comment. I find this kind of exchange very helpful and from a selfish point of view, I'm learning a great deal. In the end, we'll all hopefully benefit from sharing our respective experiences and knowledge.
I'm going to be passing by Ladysmith this Thursday on my way to Nanoose Bay for a week or two of project work on our motorhome. If I didn't have our beast Monty with me and our Fiat in tow, I'd happily stop by our favourite bakery. Another time. It's a pretty town.
Cheers, and thanks again!
Motsenbocker’s Lift Off 41116 Silicone Latex Caulk and Foam Sealant Remover is a great resource to remove that old caulking... stuff works wonders. Apply, wait a few minutes and start wiping away with a paper towel. Water-based so fair easier to remove any residue, unlike WD-40 and the like.
What a find, thank you! I've written this down so I can try to find it. Hopefully I can find it in Canada. I'd like to get rid of all the old caulking on our motorhome and replace the seam joints with marine sealant / adhesive, just dreading the process of removing of the old stuff. Your product sounds like the answer. Really appreciate that you've offered this information. Cheers!
Water will wick down the screws where they penetrate a gasket or sealant bed over time unles they are also sealed. I've had to replace a couple done this way. I had to replace the wood carcass and lining because of the slow nature of the leaks just for fun.
Thanks for explaining your experience. It's helpful. While I haven't added excess sealant over the screw head and washer / gasket on my sailboat before (stanchions, deck fittings & ports), after maintaining it this way for many years with success, your comment is hitting home that I may be having water issues below deck and not being aware of them because of the slow nature of a leak. I know we're talking RV's and not boats here, but it's my experience with my sailboat that led me to follow the same sealing method on our motorhome. So, why wouldn't I seal the screw heads with a spot of sealant, as extra insurance? I really appreciate you chiming in, thank you!
Great video. Thank you. Surprised you didn’t apply sealant to the screws and fender washers. I would think water would penetrate over time. Thanks for sharing!
Thank you, I'm glad you watched the video. And your comment about sealant to the screws and fender washers is a good observation. I didn't do a very good job at showing the sealing of these two things, something I regret.
They are actually sealed quite well. Before laying the broad bead of sealant along the flange line, I squeezed sealant into each hole and then covered it all with the broad bead of sealant. When I placed the skylight over the holes and the broad bead of sealant, the sealant oozed up and down through the holes. When I tightened the screws with fender washers underneath, the sealant naturally oozed around the screw head and washer, and I wiped off the excess. It gives the appearance that there isn't any sealant around the screws and washers, but there is.
When I use this method on my sailboat as I have for many years, there are places where I can look underneath the deck to see what is happening. The sealant always forms a tight seal around the screw, all the way through and when I see sealant around the tip of the screw, I know it's good. The trick is to use lots of sealant and be prepared to wipe it clean where you want a nice appearance - without compromising the seal. This is what has given me confidence to follow the procedure on our RV.
To be extra cautious on the RV, there is no harm in placing a smear of sealant over the screw head and fender washer. I think most people will likely want to do this. I didn't think it necessary but maybe I'm just being too fussy, wanting a clean look. The RV roof top isn't like a boat where appearance is important. Perhaps I have to change my ways!
Thanks again for asking the question. It's a good one and I appreciate the positive way you asked it. Cheers!
I woulda have used the washers with the rubber back . Much better seal . Nice work !
Yes, I agree. I never thought of this and I'm going to look for some for future projects. I like that idea. Thanks for the tip, and for your kind comment.
Roofers use those on metal roofs with exposed fasteners. They work great, but they do have a limited lifespan, because the rubber washer is exposed to the elements. But "limited" can still be quite a few years, perhaps 20.
I always thought there was a better way. Thanks for making this video. Job well done.
I'm glad you found it helpful. Thanks for your kind comment. I wasn't too sure how well it would be received because it's not a common practice on RVs. But it's all I know so I went with it. It's reassuring to receive your message, thanks!
First time viewer - I agree. I seal everything on my class A like I did on my 1961 wooden Chris Craft Connie. If the item and material holds up on a boat it should work good on a motorhome. Also for electrical connections - marine grade.
Welcome, I'm glad you found us. I'm completely with you using marine grade materials and having owned a classic Chris Craft, I know you must be a pro with a lot of experience. I love that era of boat, particularly boats made in the 60's and 70's. I just watched a glimpse of your Connie on your TH-cam home page. We have a 1972 Islander sailboat that we still cherish and somehow keep afloat. You have lots of those around SF. Cheers!
Butyl tape takes longer to apply than the gooey self-leveling lap sealant in a caulk gun. Tape must also be evenly compressed, so mind the torque and even spacing of the fasteners. Many liquid sealants won't stick or may even damage the integrity of EPDM roofing, so double-check that it's a safe substance first. The area must be CLEAN for the best chance of repairs to hold. While a boat may get worse water exposure, its not likely to experience the racking and twisting that an RV gets, whether from highway wind, or uneven stabilizer jacks. Remember it's only a box on wheels thats designed to be lightweight (not structurally sound). A boat is a streamlined vessel with strong ribbing to limit deforming in the waves and wind. So remember to use sealants that will remain flexible!
Thank you, your explanation and caution is very helpful. It's bang on. I value what you've said and I hope many viewers read it as well.
Love this video. You nailed how I feel about that old caulk. I love will be doing mine like yours when it’s time.
Thanks for posting.
Oh good, I'm glad the video was useful and that you told me about your plans. I wasn't too sure how viewers would respond to this approach to sealing RV attachments and hearing from you has made my day. I hope this technique works well for you. Thanks for watching, and for your comment.
Nice work. I will do the same next time I need to re-seal. If it works for boat applications then its going to work great for an rv. Thanks for posting such a helpful video!
I'm really happy you found it helpful. Thanks for telling me. The boat experience has helped me a lot, I've made so many mistakes along the way, but in the end I've come to the conclusion that you point out - do things to the standard of keeping a boat dry and nice looking, and everything should be just fine on the RV. 24 years ago a person who was responsible for sealing aircraft windows taught me how to seal deck attachments and ports on my sailboat. I still have that same sailboat, and it's still leak free. Well, sort of! I used the same technique he taught me on this motorhome skylight, so here's hoping! All the best, thanks again.
You might have said this, but what about a drill size larger hole in polycarb skylight that size screws to secure. That way a slight bit of expansion available from hot and cold temps and wriggles of our RVs. Maybe less chance of cracking. Great a episode.
It's a really good point and while I did mention in the video that both the skylight predrilled holes and the holes in the fibreglass roof need to be oversized, enough for the screw to easily drop through so there's no stress on the polycarbonate or fibreglass - I could have done a better job of explaining this point. I'm glad you're pointing it out here because I agree completely with you. I mentioned the need to so this to avoid future stress cracking, but you've taken it a step further by mentioning expansion from hot and cold temperatures that I didn't consider. Thank you! I'm glad you watched, hope you come back. Cheers!
Your work is first rate. Thanks for the great video!
What a nice comment to read as my computer opened up. Your words mean a lot to me, thank you. I'm glad you watched the video, hope you stay around. Cheers!
Excellent idea. I used Sika Flex on my boat. Great material!!
It really is, I agree with you. I re-bedded all my stanchions and other deck fittings, including new ports, on our sailboat years ago with Sikaflex and they're still holding. Great stuff for boats. Glad you watched this video and commented, thanks!
I bought a 2007 camper nice unit well taken car of. I inspected the roof and factory sealent was crusty breaking in chunks. I removed all of it. I did not find any leeks. I spent a small fortune on eternabond tape. And seeled everything with it. After living in it for 6 months, no leeks, and the tape is just as i put it down. It did not shrivel up and continues to maintain its bond. A homeowner told me about this tape. When i ask gow well does it last, he said it was 6 years so far, and it hadn't shriveld up and looked new, except slightly brown, yellow, color from white.
Thanks for telling me about your experience with this tape. I've never used it. It sounds durable. I have been trying to figure out how to re-do the front and end cap seals, where the fibreglass caps meet the main body of our motorhome. I want to strip off the old caulking, but it's not the best example of where I can use the marine sealant effectively without lifting and cleaning out under the aluminum strip. The tape you're mentioning sounds like a possible solution. I may use it. Thanks! And thanks for watching the video and commenting, I appreciate you doing this.
You need to warm that stuff up, take a flat dull putty knife, scrape the stuff between screws so you can remove screws. Dull flat blade to work under the rim, gently remove it. Warming helps a bunch too. I changed my dollar store fart fan to a fantastic type fan on a membrane roof and no damage, but the dicor wasn’t hard like that either, thanks
Thank you Mr. Lahey
You are most welcome! I think!!
@@ThisOldRV2023 haha there is a character from "the trailer park boys" series. To me, you sound like him a bit. Great character on the show, even better person in life. RIP Mr Lahey
That is funny! I do know that show and character and he's what I was hoping you meant - I just wasn't sure. He was a great character so I'm taking that as a compliment. I've also been told I look and act like Inspector Clouseau on the Pink Panther. I guess I'm just not normal. Nice chatting with you, thanks for the touch of humour. Cheers!
Good job…. I like the tape and so on idea. Clean and effective. I am a Dicor user and like your idea to try. A tip that I do… I only cover each screw individually. I use putty tape between the cover and roof. I never ever ever use silicoln…
Thanks for your message, for putting your faith in this idea. I think you'll be happy. And I like your tip about covering each screw individually. Extra insurance, right? Yes, let's keep away from that silicon stuff. Bye for now.
I use a small 12 volt drill with a bit, run it 90% in on all, come back and finish with hand held screwdriver. Much agreed to be careful and don’t strip.
I think if we used butyl tape underneath, then touched each screw head, in theory, it should not leak. Maybe a thin bead around the flange as added intrusion protection? It will be neat to see how well this repair holds up.
I think so too - what you describe should work well and it would be much neater than spreading lap sealant broadly over the flange. And, it would likely be far easier to remove in the future, than the Sikaflex marine sealant / adhesive that I used. Humm.... I think I like your idea better, wish I knew you a week ago!
I learned some new tricks...thanks Bill!
Great, I'm glad some of it was useful, Mark. Always good to hear from you, thanks for staying with us. M says hi.
For future projects, an oscillating tool with a scraper attachment is much quicker and cleaner
It's a great idea, thank you. I still have other hard crusty seams to redo and I will use this kind of tool in the future. I certainly do seem to choose the hard way of doing things, and I always appreciate ideas that will help. Many thanks!
The screws will need to be sealed in my opinion (I’m no expert). On a vertical surface you might not need it, but on the roof I’m pretty sure you’ll need some type of sealant to keep water from wicking down to the wood.
This is a good observation and one that a few others have questioned. I can sure understand why. What I'm going on is my experience with my sailboat over the past 24 years. I've re-bedded all deck fittings and ports using this process and so far, I haven't experienced any wicking of water below decks. The marine sealant that oozes up the screw hole forms a nice, clean bond as you screw downward, effectively keeping water out the length of the hole. Picturing it, when squeezing sealant into each hole, the sealant naturally seals the hole around the screw and oozes up to the base of whatever you're attaching - and downward to completely fill the hole. I then simply wipe off the excess sealant that has oozed out from the screw head, so it looks clean and tidy - just as you see on most boats. While it looks clean and you'd think there is nothing to stop water from penetrating downward, there actually is a complete seal that should last for years. This has been my experience. When I bought our motorhome, I thought - why wouldn't this same process work on an RV roof? That's why I did so and posted the video. Having said all of this, there is no harm by placing a small amount of sealant around the top of each screw head, as extra insurance. I get what you're saying. I personally don't think it's necessary and it always looks a bit crappy. I'd never do that on my boat. On the other hand, it's on an RV roof and who's going to see it. I think a lot of people will follow what you're suggesting and I understand that. Thanks for participating in the discussion, it's all helpful. And who knows, you may find me topping off each screw head with sealant one day!
Add washers with neoprene on the bottom. They are used for metal roof trim and the neoprene deforms and seals under slight pressure.
@@ThisOldRV2023 I do all the work on my sailboat and RV and agree with the comment above that you should seal/protect the screws and fender washers to complete the job. I learned a great trick from my brother a professional roofer. Once you are done sealing the skylight, use what's left of the tube by placing a dolup on each screw and washer so they are protected from sun and shed water. You are going to end up throwing out the left over sealent in a month or two anyway so may as well get the extra protection.
Great idea, thanks. I'm not aware of these washers but will find some to keep in my supply container, to use next time. Really appreciate your help, it's a useful tip.
Ok, you've sold me on this. I haven't done this in the past but I can understand the extra insurance it provides. And you're absolutely right, I do have marine sealant left over, I've keep it taped off but it won't last long. I'm going topside to apply those dolups!
sand, brush on gel coat, sand , buff. So why not opening vent above shower? great job
It's a good thought. I went right to a solid skylight because that's what was there, I didn't think of a vented skylight, which is a very good idea, because there is a powered opening vent in the bathroom within 14 inches of the skylight. It works well. But good thought, thanks. And thanks for watching and your kind words.
Thank you teachering how seal it the right way
You're most welcome and while I believe in this method, some may say it's not the only way and I'm sure there are other effective techniques as well. I just like this one. I'm glad you do too. Thanks for watching.
Great video, but I wondered why t 18:53 he tedious work of scraping was not done from a ladder inside the RV.
Well, that's a very good idea! I read your comment to Micheila and we both laughed, because it never occurred to me at the time. It would have certainly been safer and quite comfortable. Sometimes you just need another person to point out the obvious. Thanks for watching, and for the suggestion.
Great informative video. Thank you!
It's kind of you to write and tell me this. Thank you, I'm glad you found it helpful. All the best!
I have always thought that caulking, or sealants are overused. The one that drives me the craziest is the silicone, everybody uses it for everything, and there's a few situations where it's really good and most of the other applications where it's not. And then you mentioning how building up your caulkin actually provides a ridge which becomes a water retainment feature for supplying small crack a constant source of water ready to leak through when the temperature is just right😊😊
You sure nailed it, thank you! You describe the water pooling effect perfectly and I'm sure how you describe it was the way it happened. And I agree with you about silicone. I hate coming across that stuff in seams and having to somehow scrape it out. There always seems to be residue left over. Let's put that stuff in a hot air ballon basket along with lap sealant and send them into space! Really appreciate you watching, and commenting.
@@ThisOldRV2023 worse than what we already mentioned is the window or skylight or whatever that's leaking, so rather than stripping it back and doing it again right, more sealant is added. How can more sealant over sealant that's already failing be expected to work
Exactly! Completely removing, if possible, the "whatever" and resealing it properly will save a lot of aggravation. I had almost fallen into the trap of simply adding more lap sealant until I woke up! Enjoy our chats, thanks!
Did you need to put down any extra sealant around the screws? This was a terrific video, thanks for making it!
It's a really good question. And thanks for your kind comment, I appreciate you telling me. About the screws - I squeezed extra sealant into the holes before fitting the flange to the roof top. I then ran a wide bead of sealant over these holes and along the entire line of the flange.
When the flange was placed, the pressure naturally forced sealant around the flange base and when I turned the screws through the sealant Into the roof, the sealant oozed out but followed the screw into the wood structure below the roof line. It should form a nice tight bond around the screw and you know this when the sealant oozes out around the fender washer and screw head at the top. I then just wipe away the excess so it looks nice and clean.
Some people recommend topping the screw head with an extra drop of sealant as extra insurance. There's no harm in doing so, but I don't think it's necessary.
I've gained confidence using this sealing technique on my sailboat for years. In places where I can see the screw or bolt where it protrudes below deck, I know it's a tight seal all the way down when sealant is visible around the entire screw or bolt. The trick is to use quite a bit of sealant and then wipe away the excess. And on the top, if you see sealant around the screw head, the seal should be effective.
I hope this helps. Thanks again for watching our video. Cheers!
I agree 100% I too like to use a hand tool for that tactile feeling how exactly the screw in gripping into the wood and also to prevent over tightening that poly carbonate skylight. Nice work. Also if in a year or so a slight leak develops around a screw you can switch it out and reexpoxy the hole. Worst comes to worse you put eterna bond over it all. Ok gotta go now get your BP meds..LOL
Thanks, you explain things in a really clear way and I'm glad you're mentioning the benefit of being able to clean up a screw hole if necessary - because you'll be able to see and inspect it. I'm glad you commented, it will help people and you say it better than I ever could. Many thanks!
Great info! I just had to add a tube of Dicor and was thinking, there HAS to be a better way. #jealousofyourroof Also, WD40 is like Duct Tape. No end to what it can do!
Oh that's funny, you sound just like me when I did that last year - before rebelling this year with my marine Sikaflex. And you're right, with duct tape and WD 40, there isn't much you can't fix. Glad you watched our video and made your comment. We think alike! I just looked at your channel and subscribed. You both do a great job, and Denver & Annie too! We're on different sides of the continent (you in Indiana and we on Vancouver Island in British Columbia, Canada, but you never know, we may pass each other one day. We hope to do a circular journey before we get too old, beginning on the west coast of Canada, across Canada, down the eastern seaboard of the USA, across the southern part of the USA and north back to British Columbia via the west coast. For now, we do as you're doing, home based during part of the year and then hitting the road (when the weather becomes crappy on the west coast). All the best, safe and happy travels.
To avoid gouging when using a chisel - turn the chisel over, bevel side down. The bevel is there to keep this from happening.
I'm embarrrassed that you've had to tell me this - this old chisel was passed down to me by my Dad. He would be very upset with me! Thanks for watching, and I appreciate your comment.
Great job!! Awesome video
Thank you! Hearing this from you means a lot to me. I wasn't too sure how this video would be received - I'm not very polished and I tend to do things the hard way, but in the end I hoped some people might see the value in this method of sealing. You've made it all worth while. All the best!
Nice video. You remind me of an old guy I know...me! LOL
Thanks for watching the video and telling me. Let's stick together as old guys, it's not that bad, and I bet you're better looking than I am! Cheers!
Nice work sir!
Thank you! Words like yours make it all worthwhile, I really appreciate you watching and commenting. Bye for now.
Great job and great Video
Thank you! I'm glad you watched, sorry I wandered a lot during the video.
Try using a hair dryer or heat gun and it WILL come off way easier!
Well, now I feel kind of stupid because I do have a heat gun. I will try this next time. I think part of me is a little apprehensive with heat, knowing I have overheated surfaces in the past. I suspect the low setting would have worked well. Thanks for the tip, and for watching!
Also put away the wood working tools and use a proper putty knife. I can peel all the self leveling dicore, even off of a crappy thin membrane roof without damage. Also a magnet or a good stud finder can find the screws if needed.
Ok, I got it, no more chisels! I'll pull out my crappy putty knives from now on. Cheers!
I was 8 yrs old at the 1959 nyc boat show that had a marinetex display featuring a patched lapstrake dinghy.
3m 5200 woyld be a good 4ever choice as well
That is really interesting! Wow, for you to remember that is amazing. I had no idea it's been around since 1959. I was assuming it was a relatively new product. You and I were born in the same year, and I don't think I'd remember something like that. You're doing much better than me! Thanks for sharing this, much appreciated.
Yes, that stuff is amazing. I have used 5200 on our sailboat, but only for things that I don't anticipate removing for a long time, or, I want to make sure they never come apart. It's sure a strong adhesive. 4200 is a little more gentle for removing. I was searching for 5200 not long ago while in Mexico. The marine shop wanted $136 USD for one tube! I passed. You're right, 3m is a good choice. Thanks for the comment, and for watching.
Next time try a heat gun to loosen the sealant.
You know, I was about to use my heat gun and resisted, because I didn't trust myself with maintaining the right level of heat, risking damage to the roof. I guess I'm getting too timid in my old age. Having gone through this, next time I will take your advice and use my heat gun. I think you're absolutely right. Thanks for watching, and for the useful tip.
Interesting. I'm shortening a schoolbus for use as a toy hauler and used 3M 5200 fast dry between the roof panels prior to riveting. Hopefully that will keep the water out for good.
That sounds like a fun project. 5200 is an amazing sealant / adhesive. I'm sure it will keep you watertight. I use it a lot on our sailboat, but only for those attachments where I need a forever seal and adhesion. I trust it completely for things like attaching an underwater transducer that I can't afford to have come off or to leak. It never has, after 12 years. For those items that I want to be able to remove sometime in the future, I use 4200 which is a little gentler. I suspect you're never going to want to remove your roof panels and in that case, it looks like you made a good choice. Wishing you leak free happiness! Thanks for watching our video. I wish you all good things with your school bus project.
Looks good Bill!
Thanks, David! You're the pro, the guy I learn from, so for you to say it looks good, I'm over the top! Cheers my friend.
Great job my friend 🤗👍🤗🏋️♀️🤺☦️
Hey, thanks a bunch! I love your enthusiastic reply, you've made my day. Cheers!
The reason for the goopy stuff for rv's specifically is because the mfg's use very thin roofing materials that expand a lot in the hot sun and need lots of the goopy stuff to stay sealed properly, stainless steel roofs come to mind.
Ahh... I get it. Makes sense and I guess more is better in this case. I can imagine the heat buildup on the roof of these things. I appreciate you mentioning this, it helps me. Cheers!
You're right, look at any boat in the water and you won't find any RV lap sealant holding all the hatches down in a climate way worse than an RV will ever see.
Thanks for seeing it this way. This is what drove me to question this lap sealant stuff and I laughed at the thought of what boats would look like if the boating industry followed this practice. It would be fun to dress up a boat in a marina with lap sealant as a joke, and watch the reaction of people passing by! This is the child in me. Thanks for being with me on this one, it means a lot!
Having built my 40’ sailboat I now turn to places like West Marine when looking for items for my RV, cargo trailer conversion.
Perfect, I do too. We don't have any West Marine's on Vancouver Island anymore, but I turn to a local marine store in my hometown that helped me refit my aging 36' sailboat. I haven't ventured into an RV supply store for a long time. Happy sailing, and RVing.
Calm seas may friend.
Great Job Sir . A bit of " Attention to Detail " goes a LONG WAY .
Thanks so much! I tend to be a bit over the top with making tidy seams. I must have OCD! Hoping not, but I sure appreciate your kind words. Thanks for watching!
What about the posibility of water entering under the screw and fender washer? Did you put a dab of sealant next to the screw before putting the scres in?
It's a good question and observation. Yes, before running the main bead of sealant along the flange line on the roof, I pumped sealant into each hole. The pressure of the flange on the main bead of sealant naturally pushed sealant through the top of the flange hole, and when I tightened the screws, sealant oozed up and under the fender washer and screw head. I wiped off any excess, and this is why it may look like there is no sealant around the screw head or fender washer.
This is the method I have used successfully on my sailboat for many years. When I thru bolted into the boat deck and looked down below, in the cabin of the boat where I could see the deckhead, I always verified that the sealant was sufficient to cover the entire bolt (or screw) as it entered the hole, and that the sealant followed the bolt or screw through the hole and also oozed through to the top of the bolt or screw. It was always a very secure seal, all the way through the hole and up to the screw or bolt head.
While I can't look into the under roof of our motorhome to verify the extent of the sealant, I expect the same will happen as with our boat. The trick is using a lot of sealant and being prepared to waste a bit and clear away the excess before tidying up the seam, so it looks professional and clean.
I hope this helps.
being in a shower ..should that not be an operating vented skylite ???
It's a very good point. I went straight to a solid covering because there is fan powered main opening bathroom vent within 14" of the skylight dome above the shower that's been effective at drawing out moisture from the shower. It seems to be well positioned. But a good observation, thank you.
Excellent
Thanks a lot! Your one word has made my day, I really appreciate it. Thanks for watching, hope to see you again.
I've seen a build using a double sided Butyl tape and roofing screws with a built in sealing washer to seal and spread the load.
It sounds like this would be an effective seal. I've never worked with Butyl tape and I sure like the idea of a built in sealing washer. Thanks for sharing this information, it's interesting and helpful to me and I'm sure for others.
Must be from New York,, I detect a little bit of Irish rougue accent. Top of the day to you Sir.😂
I'd love to be an Irish person from New York, two places I admire. Sorry, I'm Canadian, born and raised in British Columbia. I could have fun with this accent thing, thanks for mentioning it. And happy to have you with us. Top of the day to you too, my friend.
Looks clean and a job well done. What did you do in the past before you retired? I will be waiting for the next video.
Hello my Nanaimo friend! Thanks for watching and for your kind comment. As for my past - I did something far removed from tinkering on this old RV. I was a hospital administrator. See you again next week.
UTubers are NOT responsible for ads on their site. UTube is.
Thanks for saying this. I felt bad when one viewer complained about the number of adds, thinking maybe there is something I can do. Appreciate you chiming in.
I see you have a fiberglass roof, most newer roofs are thin membrane. Nice, careful install.
Yes, I like the fibreglass roof and it's surprisingly thick. I guess it was the era (1997) when fibreglass was being readily used, resins were not too expensive at that time. I wish now that I had explained more strongly in this video that the removal technique I was using should never be tried on the thin membrane roofs of today that you're mentioning. So much easier to rip through. Thanks for watching and for your kind words.
Interesting method. One question, how easy or difficult is it to remove the marine sealant when you have to change the skylight? They can break for various reasons, also other roof fixtures. Difficulty of that might be the reason. Note: I'm an RV tech.
It's a very good question. You're the first one to ask me this - I bet you're a good RV tech. My experience has been positive over 24 years of using this method and Sikaflex sealant adhesive on my sailboat. I first applied it in 2000 when all ports needed re-sealing. I replaced these ports with new ones in 2015 and had no trouble removing the old sealant and ports. It did take time, but it wasn't messy or gooey. I use a very sharp slim blade to cut the seal and break away the fixture, whether it's a port or deck fitting, and continue to use a sharp blade for most of the removal. It tends to cut away in strands. I can never remember having a difficult time removing any fitting that I've sealed with this sealant adhesive. Some boaters will use 3M 4200 or 5200 on their seals. Now, this is difficult stuff. I would only use the 5200 on a forever fitting, like an underwater transducer. 4200 is a little more gentle. I like to stick with the different Sikaflex blends, easier to use and remove. I hope this helps, and I'm glad you asked.
And you think RVs are expensive now
I’m not saying I agree with how sloppy RVs are put together but you spent more time on a skylight than they spend building the whole unit (slight exaggeration)
The manufacturers roll the dice on the roof and odds are they make more money the way they are built. Why a lot of things are built the way they are.
For sure, I agree completely. They couldn't afford to keep me on staff, I'd bring their assembly line to a halt with my slow moving, plodding method and they'd go broke very quickly. I even drive my wife nuts! I think you've perfectly answered the question as to why manufacturers use the methods they do. Appreciate you doing this.
A heat gun has entered the chat!
There were no screws in our 2003 Aliner skylight flanges.. only the adhesive held the skylight in place
I like that, a lot. I suppose I could have done the same with this Sikaflex adhesive / sealant, having just filled the previous holes before fitting the new skylight. Why drill holes if you don't need them - ok, next time! I appreciate your comment, and that you watched the video. Thanks!
If you want to prevent lap sealant from degradation then paint it with polyurethane based paint
This is a great tip, thank you. I didn't know you could paint lap sealant. Matching the paint colour to your rig would help with appearance, wouldn't it, in areas where the lap sealant is somewhat exposed, like the front and end cap seams that curl down the side of the rig for a few inches and can be seen from the road. Thanks for offering this suggestion - but remember, I'm not a lap sealant fan but I do respect your knowledge and experience with this product. Cheers!
I just subscribed to your channel, thank you for this fellow Canadian. What d you think of Eternabond for sealing a skylight?
Hello fellow Canadian! Thanks for subscribing. I'll do my best to keep you interested and ask you, Canadian to Canadian, to tell me when I get off track or start to lose you. I'm not qualified to say much about Eternabond because I've never used it. It strikes me as a good fix for an immediate leak situation, something to have on hand for emergencies. But, I have seen others use it as a more permanent seal over existing sealant jobs. Personally, I don't like to cover up any seam with either tape or lap sealant, because you can't see what's happening underneath. Although, I believe Eternabond has a clear tape that would allow some inspection.
I guess I'm old school - I prefer a good marine sealant that oozes out when you bring two surfaces together, especially a skylight flange and roof surface, and you can see the extent of the seal around the flange including around the screw heads - and keep an eye on it over the years. While this method will take some work to remove if you had to, I wonder how difficult Eternabond would be to remove? Hopefully, other viewers with experience with this tape will see our chat and chime in to help us both out. I'd like to learn more about it too. Cheers!
@@ThisOldRV2023 I bought a truck slide in camper not long ago that is all sealed up with Eternabond, so sealed up in fact that it was too much. To remove this stuff which seals great actually you have to heat it up, peel the outer membrane, heat up the residue to remove the bulk of it, then I proceeded with mineral oil and WD 40 to remove the rest. It is not eternal but close to it! Lol.
Whoa ... it does sound lasting! I love your last sentence. It sounds like I should have roll of this stuff on hand for an emergency. Thanks for telling me about it. Bye for now, cheers!
Who developed the lap sealant, the companies selling it for $15 a tube, lol. I installed vents on vans 50 years ago, we used putty or butyl tape, can’t remember for sure, but that and some screws was it. Now I realize there was metal underneath not wood so if you got a leak, it didn’t rot. I think if you could warm it a little, that would help. Mine was new when I replaced the old cheap vent, so the Dicor was soft enough to roll off, and I may have used a plastic scraper or small, dull putty knife as well, but would never use a sharp chisel. Too easy to cut the roof membrane on newer camper.
That's interesting about how sealants have changed over the years. I'm sure you've done few of these and I respect you when you say heat would have helped me remove the old stuff and that a chisel would not be something you'd use. I should have been stronger in my explanation for using a sharp chisel, only because it was a fibreglass roof, a hard surface. I'd hate for someone to think it was acceptable to use on a rubber or fabric membrane roof, which is probably the more typical type of roof. Your thought of a dull putty knife and heat sounds better. See, we all learn! Thanks for watching and commenting, glad you did.
Yes we do, I’m grateful for TH-cam. I’m 64 and had to learn everything the hard way, before TH-cam, lol
Use dishwashing liquid and your finger to level, don't over use self leveling
Good tip, thank you!
We use it on or OTR Semi trucks. Great product Sikaflex I redid my whole camper in 221shes water tight now
Thanks for telling me this, I feel even better about Sikaflex knowing that it's used this way. I understand the semi truck part, but may I ask what OTR is? Off the road e.g. logging trucks? Glad your camper is watertight. I like to carry the small squeeze tube of 221 with me for those immediate fixes. Thanks for watching our video.
@@ThisOldRV2023 OTR is "Over the Road"
Got it, thanks.
Looks good Bill.
Time to move on to the next project?
Glad you saw this Brian, thanks for watching. Yes, time to start an inside project - finishing the wallpapering job I started two years ago. I'm driving back tomorrow. I may see you this week? I hope so.
Were you able to go through how to mix and apply marine tex?
Oh shoot, sorry. I know I missed showing the mixing method in the video. I ran into problems around the time I was doing this and I couldn't capture it well on camera. The next time I use marine tex I will show the mixing method. In the meantime, if you are using it, here's what I do.
A cut up plastic milk carton, about a 4" square section, makes a simple and useful mixing platform for the marine tex. Wearing gloves, use a popsicle stick to remove the amount you need of white resin from the jar provided in the package. Place this blob in the centre of the plastic milk carton section that you've cut up.
Using the hardener provided in the package, drop the hardener onto the white resin blob to a ratio of 5 to one. 5 parts resin to one part hardener. Just estimate the right amount when you're dropping the hardener onto the resin, the mixture is quite forgiving. If you're in a hot climate, you can get away using a little less hardener. Mix it really well with the popsicle stick.
Use the popsicle stick to apply the mixture to whatever you're working with. While it does sand and scrape off once cured, it's best to not leave too much of a ridge because it dries to an extremely hard surface. Make a nice smooth finish, as best you can. And, you don't want to waste too much because it's expensive. Best to make small amounts and use it up, rather than have some left over. I always have a bundle of cut up milk cartons available and a package of popsicle sticks.
Please remember to use a fresh popsicle stick every time you need to dig out more resin from the container. And use a fresh plastic container section each time. If there is even just a fleck of hardener on your popsicle stick from when you were mixing, it will ruin your resin in the container. It will become stiff and you can't work with it.
Once it's hardened, you can use a sander or scraper to form your surface. Please use a mask, it's dreadful stuff.
I hope this helps.
I noticed that you didn’t put any sicoflex (spelling?) on top of the screws. While I realize they go through the sicoflex, … well, … they go through the sicoflex. It seems likely that over time, as they loosen a bit due to travel and temp variation. This could introduce a whole collection of entry points for water! I think I’d feel more comfortable with something over those. Perhaps, eternabond.
Really good observation. Others have mentioned this as well, so I best listen. What I'm going on is my experience with my sailboat, having re-bedded all deck fittings in this same manner, without any leaking over many years. But it sure wouldn't hurt to place sealant over the screw head on a RV roof, because who's worried about the appearance up there. On a boat, not such a great appearance. This marine sealant seems to remain in tack and a solid seal with movement and heat variation. I guess I have to come to terms with appearance vs practicality. Sure appreciate your comment, thanks.
...now to solve for that rediculously thin membrane acting as the sole seal on modern RV's. Just got my first modern RV (5th wheel) and was surprised at how thin it was and how poorly it is adhered to the OSB.
I understand what you mean. I watched a video the other day of a newer model Mobile Suites 5th wheel, a very expensive unit, and the owners experienced the roof membrane being torn off while driving. The video showed the exposed OSB or plywood roof, with the fabric membrane torn in sections. I'm wishing you only good things with your new 5th wheel. Happy and safe travels. The video on TH-cam was Liz Amazing if you're interested.
@@ThisOldRV2023 Thanks. I will check it out. sounds like the edges came up on their experience since having a little low pressure creating bubbles shouldn't rip the material. I am reluctant about tree limbs and walking (even though they call them walkable roofs).
Last time I replaced a vent I just used putty tape. Never had a problem using that.
I've never used putty tape, but I gather it's broadly used in the RV industry. And I think that's what I was removing when I took off our skylight in this video. I believe it was the original skylight that Beaver placed on the motorhome back in 1997. So it lasted a long time. I guess I've been brainwashed by the marine industry that I'm more familar with. I find marine sealants easy to work with and they last a very long time. I'm probably overdoing it, I'm sure putty tape is just fine as you've found - and I suspect a lot cheaper. Thanks for mentioning it, and for watching the video. Cheers!
@@ThisOldRV2023 I don't know one way or the other if it is better than anything else. I used it on my old 1979 Layton travel trailer and the vent on a ford high roof conversion van. Doubled it up due to roof not being perfectly flat. It's what the dealer that sold me the vents recommended. I think I paid 10 bucks for a roll, still got some left after doing to vents. I do know a 3 inch putty knife scraped the old off quite easily. Not sure if it works with rubber roofs or not. Those were both steel roofs. We have since upgraded to a 2018 StarCraft and last month traded in on a 24 keystone. Not sure if I will use it on that or not
Is that similar to Eternabond?
@@robertmooberry725 I have no idea what eternabond is. I bought the putty tape the dealer who sold me the vent suggested for my trailer. I used it on my ford high roof conversion van as well. Worked great on the steel roofs. Was cheap too.
@@ridge69 I've used it to replace lap sealant and it has worked well.
www.crssupply.com/search-results/eternabond-roofseal-roof-repair-tape/
11:54 "Water, it finds it way in"
It is a shower. I suspect water can get in from the shower. Look at the dome. It gets wet. Water will wick down the inside of the dome under where the dome meets the roof and there is no sealant.
It's a good point. I've never tried to measure how much moisture enters the area you point out from shower use. And you're right, it's on the inside edge of the sealant so it's free to enter the inner roof structure and run downwards. There is enough room in this cavity for me to place a line of paper towels along the dome edge to see how much water might collect. I'll give it a try. Thanks for mentioning this, it's a great observation.
@@ThisOldRV2023 We have lived on a 41 foot sailboat and a class A motor-home for the last 11 years. Notice at 0:02, the crack between the roof and the carpeted hole. My roof is the EPDM, so the water can seep into the plywood, below the EPDM, rotting the plywood. Our stuff is old, so are we, so I have worked on most everything and there will be more to fail! I yearn for a land home to decrease my maintenance work!
If you've lived on a sailboat and a motorhome, you can fix anything! I have complete faith in you. I lived on our sailboat for 8 years, before sailing from Canada to Mexico where the boat now sits. Our stuff is old too (boat = 52 & rv = 27 years) and we are old as well - and we must figure out what to do with the boat while still maintaining our RV. Our next trip south will have to answer that. And yes, that crack that you're pointing out, the water once through there will drop down into our inner roof structure and potentially rot the structural sections and veneer under the deck head material - and down the inner walls to the floor as it did before I sealed things up. I guess we're both doomed to be old guys, forever keeping our boats and motorhomes alive. I'm glad you've made me take note of the inside of the dome, something I'll be closely watching from now on. Cheers!
What happens if you ever want to remove that skylight? That is called a sealant adhesive. I imagine it will be much more difficult.
You're absolutely right. I knew this was a product that was more binding than RV sealants (as you say, it's a sealant / adhesive) and I was assuming, from my talk with the marine shop owner where I bought it, that it is removable. Harder to remove than RV sealants for sure, but certainly doable. From my experience on my sailboat, if done correctly, I'm hoping it won't have to be removed for a very long time. A forever seal. I hope to be gone by then! You've raised an excellent question and I should have been more direct about it in the video. Thank you!
Electric drill , (battery) with a clutch setting is the way to go
Thanks for the tip! I really do things the hard way and I've learned a lot from comments like you're offering. It's a good idea. Bye for now.
WARNING!! This is for fiberglass only. The products used may or may not be compatible with some roofing materials. Please read before use.
Thank you! You are absolutely correct. I should have emphasized this more in the video. It's important to always read the compatability language on the tube to ensure it's going to work for your particular materials. While the product I used was ideal for polycarbonate and fibreglass, there will be other marine grade sealants (Sikaflex and others) that will work for other roof and skylight materials. I appreciate you for pointing out this warning. You're a good co-pilot!
@@ThisOldRV2023 absolutely love your videos. The humor mixed with your professionalism is outstanding. Btw, I miss my fiberglass roof! Sooo much easier to care for.
Oh thank you, this means a lot to me. I'm glad you were there to post a very helpful comment for viewers, in a very nice way. Yeah, I know what you mean about missing a fibreglass roof. So much more forgiving and easier to patch. Bye for now, and thanks for checking in again.
Coulda just used butyl tape.
Yes, this appears to be a common type of sealant to use. I've never used it but I'll look at it the next time I'm in a supply store. I guess I'm locked onto marine sealant because this is all I've known, and I trust it. Not to say something like butyl tape wouldn't do the trick and I bet it's a lot easier. Thanks for the tip, and for watching the video.
Only catch..used to attach iron keels to boat it doesn't come off without destroying fiberglass and grinding iron down. It's a forever adhesive.....
A really good point, and I can see you know what you're talking about. The 4200 and 5200 3M products I've used are truly forever in my mind, but I'm hoping this Sikaflex product will be easier to remove. Are you saying this particular Sikaflex product (295) is what you used on boat keels? If that's the case, OMG! It wasn't explained to me that way in the marine store, but I trust you.
@@ThisOldRV2023 apologies.. enthusiasm overdrive...marinetex is the keel glue...your application of sikaflex on the money...do it right not lots....great job.down with lap sealant
Oh good, thanks. You had me worried that I had applied something not intended. I didn't know marine tex was used for attaching keels, that's impressive stuff. Really appreciate your message, thanks again.
A trick I used to remove the old caulking and tarrrrr and all the god forsaken unknown junk that was put on to seal the leaks on my roof top I used a heat gun and a 5 in 1 tool to scrape the junk off and had no extra damages ! Only issue with heat gun I have it has hot and daaaaaaaang hot settings 🤣🤣
I'm feeling foolish because I do have a heat gun and didn't think to use it. I have been known to overheat surfaces in the past with my heat gun, but it only has two settings so you'd think I could get it right. For some reason I went straight to a chisel and scraper. I seem to do things the hard way, and I appreciate your suggestion. I'll have to look up a 5 in one tool, sounds like I could use that too! Thanks for your help, and for watching my video.
@@ThisOldRV2023 don't feel to bad I'm tr same way lol, but I get about halfway then realize that oh yes way to go and then try the brain fart 🤣🤣 and your welcome take care
Many thanks!
Many thanks!
Can use only glue without the drilling?
This is a very good question. Yes, with a marine sealant adhesive like the Sikaflex 295 that I used, I believe you can get away with just the adhesive sealant - no drilling in the roof. I decided to re-drill the holes and use screws because the new skylight came predrilled. Another option if you wish not to drill is 3M 4200 or 5200. I've used these sealant adhesives on my boat without any drilling, but the 5200 is almost impossible to remove. If you want something to stick forever, that's the one to use. 4200 is a little more forgiving. If you don't wish to drill, you need to make sure what you're using is both an adhesive and sealant. Some are just sealants. Hope this helps.
You still have a screw hole. Over time thermal expansion and contraction will open up the screw hole to water. While I like the concept it might be better to add sealing washers under the screw head. The reason people goop decor over the whole thing is to cover the screw holes.
I'm not sure if I'm correctly interpreting your meaning of a sealing washer under the screw head. If I'm correctly reading you, it's a very good point and I agree. I did use a large fender washer under each screw head on the skylight flange, which served to capture sealant that oozed up through the screw hole as pressure to the flange was applied and the screw was threaded in. The sealant could be seen under each screw head and presumably, formed a bond and seal under the fender washer. Is this fender washer performing the same purpose that you suggest is needed with a sealing washer. I hope I'm correct, you sound like you're very knowledgeable.
@@ThisOldRV2023 a sealing washer is a rubber but most likely fiber washer. It will expand and contract with thermal changes. It also has issues as they are often not uv tolerant and will decay over time. Butyl rubber or its equivalent have a flexible property that allows for expansion and contraction. This is why you see gaps in concrete filled with BR. It works best when you don’t have a physical barrier. For example, roofing nails are covered by tiles. Aside from the decorative feature, roof tiles just cover the nails and redirect the water. Rv skylights would be better don’t with a plastic done that slide over a rail and covered the screws holding the rail. Much like aluminum roofs are covering the screws. Decor is just a cheap substitute for the physical cover. A slide on dome or clip on would outlast the plastic so nobody bothers.
Ahh... I understand, your explanation about expansion and contraction is very helpful. Much more to it than I've given thought to and I can see where there will be failures. Now you have me thinking about a small dome cap to cover each screw and washer, something that will be UV resistant. Ok, the hunt is on! I can't bring myself to use excess lap sealant. But in the end, I get what you're saying, it does have a purpose and it's a cheap fix. I really appreciate you for offering this helpful information. Thank you!
Dicor is horrible … I’ve been used be a polymer seal since 2013 …. Never ever cracks (Through the Roof (brand name) ) there are now several similar products out there …. NO silicone
Oh good, I'm always looking for new alternatives, thanks for sharing this one. And I couldn't agree more with you about silicone! Thanks for watching our video and offering your comment.
Tighten screws by hand, only snug.
Yes, bang on, the right technique. Thank you!
aren't you afraid of water seeping through the washer and screw right into the wood underneath?
This is a really good observation and question. I've found that with bedding deck fittings and ports (windows) on our sailboat over the past 24 years in the same way, the sealant forms a nice, tight waterproof seal around the screw, or bolt, and the sealant forms a skim coating under the fender washer as pressure is applied to whatever you're sealing - the sealant oozes upwards through the hole opening and down into the hole in the wooden rv roof system - sealing the hole and screws nicely. I pushed sealant into the holes in our motorhome roof before creating the bead of sealant that you saw in the video. I would have liked to have seen more sealant ooze out from under the fender washers and around the screw heads as I tightened the screws, but I think there is enough sealant underneath to have sealed it. The trick is to use the right amount of sealant - enough for the oozing to take place but not so much that you create a huge mess around the screw head. Thanks for the thoughtful question, and for watching the video. Cheers!
@@ThisOldRV2023that makes absolute sense to me and thanks for the extensive response 😊
You're most welcome. Hope it helped. Bye for now.
I have a skylight in my bathroom so one day when it cracks, I will be doing the same repair, thanks
I wish all rv roofs were metal or fiberglass, not this new, thin membrane that is so easy to damage, cut, puncture.
Should have put sealant on the screws under the screw heads where they go in. Those are your leak points now.
Really good point. You'll be happy to know I took care of this, using the same sealing technique I've been using on my sailboat for 24 years to seal deck fittings. I squeezed sealant into each hole in the RV roof before running the main bead of sealant in line with the flange - that also went over each screw hole in the fibreglass roof. When the screws went in, the sealant naturally squeezed up through the top of the flange hole and formed a bead of sealant under each screw head and fender washer. I wiped them clean, so they looked tidy. This way, the screw has sealant around it all the way into the inner frame of the RV roof, under the skylight - and the screw head is adequately coated underneath. The trick is to make sure you have enough sealant in the holes and under the flange for oozing to take place - that you can then easily clean away. My sailboat remains leak free below deck, and hopefully the RV skylight will be the same. I can understand why you raised this point, because it probably looked like there was no sealant around the screw head. All the best, thanks for watching and for the meaningful comment.
Would you even need screws?
Really good observation and question. I believe you could use just the sealant / adhesive, avoiding screws. The marine Sikaflex that I used is both a sealant and adhesive and would probably be fine on its own. You could also choose 3M 4200 which is a very strong adhesive / sealant. 3M 5200 is even stronger, but almost a permanent fix. I've used 4200 & 5200 on my sailboat below the waterline, depending on it to hold fixtures to the hull (e.g. depth sounder transducer) without anything but these sealant adhesives. Never a problem there, so it would certainly hold a skylight to the roof of a RV. Bit of a task to remove, but hopefully you won't be doing much of that.
The skylight I purchased for this project came pre drilled, so I decided to use these holes for attachment purposes. But the screws are only holding the skylight in place while the sealant / adhesive cures. They're not necessary for securing the skylight because that's taken care of by the sealant / adhesive - the very thing you're getting at.
Now you have me thinking - I should have sealed the pre-drilled holes in the polycarbonate skylight and just attached the skylight with the adhesive / sealant, or let the sealant protrude up through the holes and just smooth it off. Next time! I appreciate you for asking the question, it's a good one.
@@ThisOldRV2023 thx for the helpful info!
You're most welcome. I'm glad it was helpful.
now head to Arizona before first snow. Oh, an land is dirt cheap now, u can have winter homestead.
Ok, you're now, we're trying to get there asap this season! We love Arizona. Thanks for watching.
What sikaflex number did u use? 🍻
I used SikaFlex 295 UV. Hope this helps. Thanks for watching.
Last experience I have with lap sealer was at strip club in the VIP private lounge 😅
Well, that's quite a different type of lap sealer!
@@ThisOldRV2023 yea…but it got the job done
Ok, we better stop!
Surprised the sealant yields to the wd40.
This is a good observation, thanks for saying it so gently. I should not have used WD40 and didn't realize it until after I posted the video. The mechanic in the following video I published yesterday explained it to me. I think my only saving grace is after using the WD 40 , I wiped the bonding edge with mineral spirits and finally with a warm dawn soap solution. Hopefully that removed any WD40 residue that could interfere with the bond. I learned something that will make me inspect that seam regularly. Thanks for mentioning this, I appreciate your comment.
I wonder why no one uses automotive windshield urethane. That stuff last over 50 years.
Yeah , great for Glass to Metal . Not necessarily Polycarbonate to Fibreglass . The Marine glue is better in this situation .
I'm not familiar with this product, it sounds tough and sure long lasting. I see there is a comment below from someone who knows about it. I'm used to using marine adhesives and sealants, so that's why I've tended to stick with them. Thanks for watching the video, and offering this information.
Maybe it was cracked against the underside of a tree limb?
Yes, that's a very strong possibility. The other possibility could be someone stepped on the flange and cracked it. When I removed the skylight, I was amazed at how brittle it was and I think this had a lot to do with any cracking. A tree limb would certainly answer the question and heaven knows, I have come close to many tree limbs. Thanks for watching and for commenting.
If he can do it, anyone can
Thanks for watching. Not too sure if your comment is a compliment, but hey, I'm just glad you watched. Cheers!
Hatches don't need extra adhesive like sika they only need sealing, use sika were extra fixing/bonding is required, use non setting sealants were no additional fixings are required, how are you going to go when you need to remove the hatch after being fixed in with sikaflex!! ,you have no idea!
I understand completely what you're saying and I agree, something like a skylight doesn't require an adhesive component to the sealant / adhesive mix like Sikaflex provides. This is a personal preference on my part, because of my experience attaching deck fittings, hatches and ports on my offshore sailboat over the past 24 years - using this method. I like the longevity, look and effectiveness of the bond between the fibreglass and component (in this case, polycarbonate) with Sikaflex - even in areas where the adhesive component isn't necessarily required. And yes, I do have an idea what it's like to remove. I have had to remove it at times, in one case every port to install and bed new ports and while it took awhile, I found it less unpleasant to remove than the sticky, messy stuff I have had to remove from my motorhome over the past 5 years. So, I stay with my marine experience even though it may appear to be overkill at times. In the case of this skylight, I used Sikflex believing (and perhaps hoping), that I will never have to remove this skylight again. I trust the seal that much. And, it's a high quality skylight that should last. Now, I just have to make sure I don't drive into anything that forces me to replace it. Your comment is a logical position to take. Thank you for contributing your thoughts.
If you have to ever get it off remove screws use dental floss string , and saw like you would a hand wire saw. It cuts through silicone type material
This guy sounds just like me, lololo, except I get my scotch
Well, I guess we must meet, we might be brothers! Happy to have you onboard, thanks for watching!
Heat melts caulking. Next time use a heated putty knife.
I have never tried a heated putty knife, thanks for mentioning this. I was hesitant to use my heat gun, but a heated putty knife sounds safer. I didn't know they existed. I am going to look for one. Thanks for your helpful tip, and for watching.
Heat gun
Yes! Next time. It takes me awhile to learn. I do have a heat gun but I hesitated using it because I was worried about creating excess heat on the fibreglass surface. But clearly, it would have helped a lot and I would have been fine. Thanks for watching, and for offering the useful tip.
TPO and rubber will stretch with heat.
An important and helpful comment, thank you. Especially considering the number of RV roofs constructed with these overlying materials. I should have emphasized more that I was dealing with a fibreglass roof with my video - and that it should be a different process with other types of roof systems.