AndyfromTucson
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Need ideas for repairing delamination on front of cabover
I have a delaminated area (about 10 inches by 28 inches) on the driver side edge of the sloped front panel of my Class C's cabover. I took the trim off that edge and have been able to reach in under the filon and pull out all of the rotten luan. My plan is to cut a piece of replacement luan to fit, slide it in, squirt in adhesive on both sides of the new luan and clamp. My problem is that I cannot figure out how to do the clamping part. Here are some of the things I have considered: - Build a really tall frame out of 2x4s stabilized by ropes, and then use spreading clamps to press a board against the delaminated area. This seems like a lot of work and materials to apply pressure to a small area. - Use really long ratchet straps running from the hood of the RV over the clamping board all the way to the back bumper to press the clamping board down. This seems like it might not give enough pressure and would be awkward to set up. - Drill a few holes through cabover panel and clamping board and tighten the clamping board down with long bolts and nuts. After the adhesive has cured remove the bolts and clamping board and patch the holes in the panel with epoxy. This seems like it would be the easiest up front, but I worry about patching the holes afterwards. Does anyone have any other ideas or experience with using one of my ideas? Thanks in advance for your help.4.3KViews0likes10CommentsGreat Stuff expanding foam adhesion test
TL;DR: Expanding foam can be an excellent adhesive for delamination repairs if it is clamped. As described in some of my other recent posts, I am in the middle of repairing a large delaminated area on my Class C cabover. I had seen a number of people mention using expanding foam as an adhesive for delamination repairs, so I decided to do a test piece using Dow Great Stuff Windows & Doors expanding foam, styrofoam (EPS), luan, and FRP paneling (orange peel surfaced stuff sold at Home Depot and typically used in bathrooms). Here is how I did it: - Put on disposable nitrile gloves (a must!) - Squirted the expanding foam on the styrofoam - Squished the wet foam with the luan a few times to spread it around until it covered the whole surface of the styrofoam and the luan. - Misted the wet expanding foam on both surfaces with water (expanding foam cures faster with water, like Gorilla Glue) - Did the same thing on the other side with the FRP. - Sandwiched the assembly between two 3/4 inch boards and clamped it for 24 hours. The expanding foam oozed out around the edges and stuck to the clamping boards, so if I was doing this for real I would use masking tape and plastic wrap or parchment paper anywhere the foam could ooze. After it cured the excess foam was easy to pull off but left residue. When I tried to pull the luan and FRP away from the styrofoam core there was zero give, and the styrofoam core was starting to break before I gave up. Some of the oozing expanding foam had gotten between the luan and the clamping board, and when I opened the clamping boards the expanding foam ripped off some of the outer surface of the luan, so it seems expanding foam is a better adhesive than what they use to make luan. Based on this test I would not hesitate to use expanding foam as an adhesive to fix delamination in luan/EPS/luan/filon RV walls if I had a way to effectively clamp the area to keep the foam from expanding (if the foam freely expands it is relatively fragile). Although I did not test it with actual filon, the FRP is pretty slick and I figure anything that sticks to it will probably also stick to filon.5.2KViews0likes6CommentsAlternatives to luan?
Has anyone used anything other than luan when repairing a delaminated sidewall? I am replaced water damaged luan in the sidewall of my cabover (as described in other recent posts), and I would like to substitute something waterproof for the luan so any future leaks are less likely to cause delamination. Here are the possibilities I have come up with so for: - Azdel. It sounds perfect, but I can't find anywhere to purchase one sheet of it. - Lexan. This was suggested by user fourthclassC. The only problem is that it is very expensive for the amount I need (like $200 or more) - Pebbled FRP panel. You know, the stuff they use on bathroom walls. It seems waterproof, comes in the right thickness, so why not? - Acrylic panel. Waterproof and affordable. Has anyone used any of these, or something else, in lieu of luan when repairing delamination caused by rotted luan? P.S. I know that preventing leaks is the best way to prevent luan rot; I just want a backup defense in case a leak does happen.4.9KViews0likes9CommentsRe: Advice needed on delamination repair
Joe417 wrote: I built two clamping bands out of 10 ft. 2x4s to go around the camper. When I put the material in place, I put a sheet of plywood over it to cover the area being glued, then a couple of 2x4 on top of the plywood to distribute pressure and clamped it to the camper with Erwin hand clamps between the clamping bands and the 2xs on the plywood. I am having trouble picturing how the clamping bands worked. Did you build two upside down U shapes that went over the top of the camper?1.4KViews0likes0CommentsRe: Advice needed on delamination repair
Thanks to everyone for your thoughts and ideas! I like the idea of Lexan to use in lieu of luan, as suggested by FourthclassC, but a sheet big enough for the whole job would cost close to $200. However, an acrylic sheet of the required thickness is much cheaper. Anyone have any thoughts on using acrylic in lieu of luan as the layer between foam and filon?1.4KViews0likes0CommentsRe: Advice needed on separated weld in cabover framing
Thanks to everyone for all the great feedback! I guess I will do my due diligence and call a few mobile welders and see if anyone is willing to tackle it. If that doesn't pan out I will probably go with j-d's idea of a triangular fish plate and some pop rivets. If I make the fish plate about the thickness of the luan, then when I re-skin I will just not put luan over the fish plate and glue the filon directly to the fish plate. The pop rivet heads will make bulges in the filon, but I can live with that. Someone doubted the joint was welded, but it definitely was with small fillet welds on the top and bottom, but not on the sides. To me the welds looked like just barely enough to hold stuff together in the factory while assembling the sidewall, and not beefy enough to be structural, but that is RV construction for you. Someone else mentioned that screws might crush the tube, tear out, etc. That is my instinct also, but the manufacturer clearly didn't think so: the two horizontal tubes stacked on top of each other in the picture are held together by three 2.5 inch #12 (guessing) screws driven through both tubes from underneath. It looks like the bottom panel of the cabover was assembled in one piece using the square tubing, lifted into place under the sidewall tube framing, and then screwed to the tube framing of the sidewalls. The screws seem to be holding fine, which is surprising. Someone else mentioned that the same weld on the other side may also be cracked. If I still have some energy left after fixing this side I may open up the weld area on the other side from the inside and take a look.592Views0likes0CommentsRe: Advice needed on delamination repair
fourthclassC wrote: Regarding delamination, I suggest you use lexan of the same thickness as luan, with holes drilled randomly to enhance the grip... Lexan sounds like a very interesting idea! I was really not looking forward to putting rot prone luan back into the wall.1.4KViews0likes0Comments
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