I've had nothing but problems with plywood

[S. Heisley]

Wow, Mike! That made me gasp! That's some of the worst damage that I've seen posted here.

I'm so sorry that this happened to you. I hope that the outside is the only damage and that the inside is all okay.

Looking at the flipped back plywood layer, it looks like it peeled back from what appears to be seam areas as there are some perfect straight lines on that area. I suspect that the water got in there and just kept going, with the help of the winds. You must've had a really nasty storm! Are you going to try to fix it? How?

Maybe you'll be happier and have better success with that new foamie that you are building.

[jdarkoregon]

What Doug Said!

How much snow did you get this year and was there any ice freeze? I guess Ice is frozen, so, was there any rain that froze, mother nature uses that little expansion to make mountains fall, plywood would have no chance against it?

John

[KCStudly]

Ouch!
You can fix that.
You should really fix that. Maybe consider putting corner trim on (with butyl tape) even if you don't skin it w/ Alum.

+1 what Sharon said. Once you get that fixed, you should jump back on the foamie project! (Easy for me to say )

I'm already wondering if I should not have planned a slouchy/standy from the get-go, and I'd like to see one done in foam. You have a head start and I'm not about to attempt a redesign of that magnitude at this point in the game, so consider this to be me putting the pressure on you. (Just kidding...mostly.)

Don't be discouraged about the damage. We're all here to offer whatever support we can! You built it, so we know you can fix it.

[SteveW]

Ahhh! I think you just scared me into reconsidering a foam/canvas build rather than my plywood w/ foam core idea. Really sorry to see this and hope you get it all worked out without too much extra effort (and stress).

[bestclimb]

Thanks for sharing with us the failure of your camper, by evaluating a failure we can learn from it.

[GPW]

Mike , that is the sole reason I decided to go FOAM and Canvas ... Nothing to rot or delaminate ... I’m trying to avoid the use of any plywood at all , maybe even going to T&G wood plank floors like the Old Timers ... The readily available plywood today is just awful about de-laminating ... The really Good Ply is Ridiculously EXPENSIVE ... and nobody makes any guarantees about it ...

[whitefishpoint]

They managed to keep PT boats together as well as Mosquito bombers and an uncle had a number of boats made of cut in half plywood aircraft gas drop tanks. It can be done but the plywood must be made properly, and what were they painted with?

Or were they, Today's plywood is composed of thin sheets of wood (of various dimensions), joined together by the generous use of glue. PT boat hulls were composed of double planked 1" mahogany fastened with monel screws. Sandwiched between the layers of mahogany planks was a layer (or ply) of canvas. Every other wooden feature on the PT boat was traditional plywood. If the hull had been plywood, as some mistakenly believe, the boat would have disintegrated from the pounding that the hull underwent while underway.

The chinese plywood they sell at Lowes looks like they've interleaved layers of MDF !

[Larry C]

I discussed this with a friend over breakfast this morning. He is a temporary wall contractor that covers store fronts that are being remodeled, and uses Luan by the pallet load. He told me since almost all paints and clear coatings available today no longer have high VOC's (solvents) the plywood industry has followed suit by replacing the solvent resistant glues with a cheaper glue that may be water resistant, but will easily delaminate when exposed to any solvent.

The veneers on luan are so thin, solvent can penetrate to the glues. He told me one of his employees was using a pallet of Luan as a work bench, and tipped over a gallon can of paint thinner. The thinner ran down the whole stack, and penetrated the the edges of most of the stack. As they were later using this stack, they discovered the paint thinner had softened the glue, and was delaminating the ply edges.

He told me the current Luan is very water resistant and they don't seal the edges at all when using it outside, but they can no longer use any solvent based coatings. They used to spray on a oil stain with garden sprayers to protect the luan A sign painter or Mural artist would follow. They now use a water based stain even though it is not as protective outdoors as the solvent based product. In cold weather they have to pre-coat the ply before going to the Job site, where previously they could spray the solvent based product even in Winter.

His suggestion when using Luan is to use the best water based products that are intended to seal plywood, and avoid anything with solvent in it.

Did you seal your plywood with deep penetrating epoxy, the one with all the solvents? Maybe that's why the delamination

[mikeschn]

Hey Larry,

Thanks for the good explanation. That makes sense, because yes, I did use a deep penetrating epoxy sealer. The one from the Rot Doctor, with all the solvents!

I went outside and looked over the entire teardrop, and there are other problem spots. I'll include some pictures later.

Mike...

[Alan Wood]

Thank you Larry for this information. This situation sure makes a lot more sense now!

[S. Heisley]

Sorry to hear of your issues Mike. There's nothing worse than putting in a lot of time and effort into a project and have a problem with it down the road. It might be a real helpful bit of information to other builders if you could give us an idea on how long it was exposed to the elements, and what materials were used. Outdoor storage on an all wooden tear/boat that isn't covered is brutal! Unfortunately, when a blister starts to show...a lot of damage has already happened. Once some moisture gets in and with the mechanical breakdown of freeze/thaw cycles, which I'm sure you have...wood materials especially a ply product tend to get torn up quickly. Doug

I agree with Doug. It's not the epoxy(regardless of whether it is CPES or Raka or....?); it's the moisture and storage problems.

[mckenney56]

The dicussion of solvents causing delamination is making me rethink coating my camper with a solvent based product. I was going to use a solvent based polyurathane porch and floor enamel product. Maybe I'll switch to exterior latex house paint and do what I did with my old painted house. Just put on 2 new coats every 4 or 5 years or so. That wany I could change the color scheme every few years.

I agree that having a place to store your camper inside would make a huge difference. Maybe we need to start a thread on building camper car port structures to keep the sun, rain, ice, and snow off of these things.

[working on it]

I'm new at this, and haven't even sealed or painted my TTT yet, but I am not convinced that solvent delamination was entirely (if at all) at fault. My people here have not had this problem with separation; maybe yours was due to weather, but mainly Luan. I've seen 5mm and thicker Luan at the big box stores that had a loose feel to the topside, like an air bubble was underneath already. I went thru 12 pieces before I found a solid piece to use to cover my 1/2" birch ply floor (to cover mounting bolts/screws and add extra stiffness). I never intended the polyurethaned Luan floor topping to be my actual interior surface...still not durable enough; it will have a vinyl or in/out carpet over it. I had old Luan in my shed, that I tried to bend gradually (even after applying hot damp towels for a couple of hours) as a test to see if I could do the "traditional" Teardrop shapes. It bent, then delaminated in my hands. That made me choose the unbent hopper/simple design right then. The straight, 3/4" cabinet grade ply I went with probably has some voids inside (no bubbles or soft spots discernable), but by not stressing the wood, the plys should remain together. I'm still going to seal the plywood with the poly/mineral spirits mix 50/50 then 75/25 (already tried a test piece, penetrated all the way thru), finishing with one coat of poly only, then topped with 2 coats of the good Tractor Supply enamel (Valspar), like on a coupla other's trailers here. But now I'm considering EPDM tape over the exposed ply edges, to try to avoid the wind-driven water infiltration that probably separated your Luan, Mike. But as an added precaution, I'm cleaning out one bay of my 3 car garage (goodbye Fiero, pickup front suspensions(2), rear axles(2), and gosh knows what else) to house the TTT from the first day I bring it home from the workshop.

[crumvoc]

I agree with the comments that it is not the epoxy. It is, however, how you USE the epoxy. I have built a couple of plywood boats of the "stitch and glue" variety. This method uses butt joints, temporarily wired, or otherwise mechanically joined, then permanently glued/sealed with generous applications of fiberglass cloth, tape and roving embedded in marine epoxy. Using that method, which is time consuming and fairly expensive, I have not had any plywood failures, including one boat that has lived it's entire life (12 Years) outside, not under cover (but stored upside down.) A great resource is Wooden Boat Magazine (a great magazine, by the way. WF Buckley once said it was the best written periodical in the English language), and Sam Devlin, a Seattle area designer and builder who has written a couple of very good books on the subject. Any other method of joining butt /edge joints is, in my opinion, bound to fail sooner, rather than later. Once moisture is introduced into the plywood, it is just a matter of time before you end up with a tasty plywood soup.

Regarding delamination on flat panels, this seems to generally be the result of a "glue starved" laminate. If one applies fiberglass cloth and epoxy directly to a raw surface, the wood will suck up some of the epoxy, resulting in a weak bond. The recommended method seems to be to apply epoxy to the raw surface, let it cure, wash off the blush, sand and then apply the cloth laminate construct.

Regarding the note from "Working on it" above, voids in plywood are also the kiss of death. Marine plywood, the good stuff, is highly QA'ed and engineered to eliminate voids. A void in plywood is just a vacuum waiting to be filled with water...

[bohemian]

Mike
Now that just sucks!
Was that the luan that has a life time warranty against delamination
Wayne