RV siding repair questions

[scotts90ranger]

I've posted in the general area on this some but have a couple questions for those that might be more versed in wood work than I am...

I've pulled the side of the thing, lots of rot, the layer of 1/8" ply is DONE so it's now almost all scraped off, I have replacement, still need to do some structure repair around the foam... I don't know how the plywood was glued on before... There's some gap filling to be done now that I've scraped the wood off. I'm contemplating getting some FRP construction adhesive since it's available in a gallon can instead of regular just in caulking tubes, thoughts? I did some looking and I don't think it should attack the foam but not sure...

For the outer skin I ordered some Landau top contact cement that's sprayable with a paint spray gun, supposed to be good stuff... not going to be fun but we'll get there when we get there...

Appreciate any thoughts.

 

[Robertmangrum.rm]

The contact glue is awesome we use it all the time at work for laminated cabinets and walls. Just beware. It can release with extensive heat. This why you can iron on those counter edges on kitchen counters. On anything we have to adhere tha will be exposed to direct sunlight aka the outer skins. We use a product called Sikaflex. If applied with the primer and all it has 400lbs per square inch of adhesive and an expansion rating up to 1/4 in.

 

[scotts90ranger]

I've looked into contact cement a fair amount and that Landau top version is about as good as you get until you get to the $300/gal stuff that the RV places use (thanks EPA), the temp rating is higher than the standard Weldwood stuff...

Many places recommend going to a roll/brush on epoxy but you would need to clamp the side in place, that's not in the cards... it's going to suck doing contact cement but I can start with 2' in the middle and work out with the sprayed stuff... still going to suck... Conveniently I'm in Oregon so the outside temp isn't too extreme in any fashion, very rarely gets under 20F and at most have a week over 100F a year... (and then it's under 105), plus there's like 100 screws around the perimeter of the side in question.

My main question is gluing the plywood on the side, I'm 95% sure the FRP adhesive will handle the heat... I'm hoping to do that portion next weekend... after tonight I won't be able to work on it until Thursday...

 

[Fast Eddie]

I've posted in the general area on this some but have a couple questions for those that might be more versed in wood work than I am...

View attachment 104991

I've pulled the side of the thing, lots of rot, the layer of 1/8" ply is DONE so it's now almost all scraped off, I have replacement, still need to do some structure repair around the foam... I don't know how the plywood was glued on before... There's some gap filling to be done now that I've scraped the wood off. I'm contemplating getting some FRP construction adhesive since it's available in a gallon can instead of regular just in caulking tubes, thoughts? I did some looking and I don't think it should attack the foam but not sure...

For the outer skin I ordered some Landau top contact cement that's sprayable with a paint spray gun, supposed to be good stuff... not going to be fun but we'll get there when we get there...

Appreciate any thoughts.

I can't see the other side but, judging from the back it looks like a gelcoat finish. That process was a basic fiberglass sheeting on both sides of a piece of laminate - sandwiched together and then vacuum sealed until cured. The damage I'm seeing is indicative of delamination. Water intrusion causes the wood to swell and spreads the fiberglass sheets apart, air enters the intrusion areas and separation ensues. Temperature changes allow condensation build up and the process continues until it's all but tell tale.

Verify your rig is constructed of gelcoat. If so, research RV construction and gelcoat construction and you may have a better idea of the path forward.

 

[scotts90ranger]

Yep, certainly delaminated, there was a layer of the plywood on the fiberglass. Once I get it back together I'll reseal everything to try to keep it from happening for a while at least...

 

[Fast Eddie]

Yep, certainly delaminated, there was a layer of the plywood on the fiberglass. Once I get it back together I'll reseal everything to try to keep it from happening for a while at least...

You must be masochistic - you signed up for a WHOLE BUNCH of FUN
What's the other side look like?

 

[scotts90ranger]

Yeah, I'm kinda crazy sometimes, even do it to myself on short deadlines... last year I did similar with two transmissions and an engine...

Oddly enough there isn't much delam on the other side... I'm just going to reseal it for now after I get the drivers side together and call it...

 

[scotts90ranger]

The FRP adhesive seems to have worked just fine, there's plywood on the side and pretty much ready for the siding to go back on... I haven't taken very many pictures and haven't transferred any to the computer yet so can't post yet... will do a pic dump in the next few days... The next annoying task will be to get all the butyl tape off the trim then scraping all the old sealant off so I can reseal EVERYTHING while it's dry and inside...

 

[Fast Eddie]

The FRP adhesive seems to have worked just fine, there's plywood on the side and pretty much ready for the siding to go back on... I haven't taken very many pictures and haven't transferred any to the computer yet so can't post yet... will do a pic dump in the next few days... The next annoying task will be to get all the butyl tape off the trim then scraping all the old sealant off so I can reseal EVERYTHING while it's dry and inside...

Check out the type of roof you have. Your choice of sealant will depend on it where it meets the roof. Fiberglass is unlikely on that model but not impossible. Most likely rubber vs. TPO. TPO will have what seems like a fabric backing. You'll want dicor for that. You don't mention where butal tape was used. Some people use butyl in place of dicor. Not always the best but 'can' do in some situations . Not my first choice. Mostly for emergency repairs. Roof edges are not the best locations for butyl sealant.

 

[scotts90ranger]

It's a rubber membrane roof, I got a tube of Dicor for the horizontal surfaces and a tube of Flex Paste for the rest. The butyl tape I'm peeling off is what's under the trim surrounding the whole side, I'll try different methods than I used last night, my fingernails are sore...

 

[Fast Eddie]

It's a rubber membrane roof, I got a tube of Dicor for the horizontal surfaces and a tube of Flex Paste for the rest. The butyl tape I'm peeling off is what's under the trim surrounding the whole side, I'll try different methods than I used last night, my fingernails are sore...

I use an old plastic bondo application blade as not to tear into surfaces unless your careless. Saves those finger tips. An old trim removal kit gets into the crevices.

 

[scotts90ranger]

I purposly spent $.30 extra per roll on Amazon that had little plastic tools with them , I have a plastic putty knife that got destroyed with aviation stripper I can modify which is part of the plan...

 

[scotts90ranger]

Here's some pics of the progress. Got a good bit done today, the side is now on and most of the stuff is on aside from the trim and windows since they have butyl rope seals instead of tape which I didn't anticipate... The Dicor showed up today intact from Amazon (unlike some of the reviews) and the escape hatch should be here tomorrow too... So far so good, I think I'm on track! The contact cement didn't spray too well out of the HFT purple gun, needed a bigger nozzle but we made it work...

 

[don4331]

I have to say I'm impressed.

 

[CrabGuy]

Nice work! You've really done your homework on that project.