One sidewall of the cabover of my Class-C had a lot of delamination. The previous owner had apparently replaced the Filon and luan in this area before, so I just took off the edge molding and pried off the Filon and rotten luan, which exposed the styrofoam and 1" aluminum square tubing framing underneath. After doing research online, here is what I have come up with for how to proceed; If you have any experience with something like this please let me know what you think:- I want to use Azdel instead of luan for the fix because Azdel is synthetic and won't rot, but I have not been able to find a vendor who sells single sheets of it in the thickness I think I need (1/8 inch or 3mm). Any ideas on how to buy Azdel or similar?- First step would be gluing the old Filon (still in one piece) to new luan (or Azdel if I can find it) using 3M Hi-Strength 90 Spray Adhesive to make a new Filon-luan panel.- Second step would be screwing the top edge of my new Filon-luan panel to the top aluminum tube of the framing to get the positioning correct.- Third step would be swinging the new panel out a bit, then getting under it and applying 3M 30NF Contact Adhesive (supposed to work on styrofoam) to the framing and styrofoam and the underside of the new panel, letting them dry per instructions, then pressing them together and using some sort of roller.- Final, replacing molding with new butyl, etc.Any thoughts, corrections or advice?

sounds like it "might" work. best of luck.bumpy

I had to do a similar repair to the front and rear edges of the sidewalls of a previous 5th wheel. Forest River-claimed "aluminum construction" actually had plenty of wood studs inside.I used products from Rot Doctor to harden up what wood studs and plywood were left that I couldn't tear out and replace (CPES product) and the built back up the holes / gouges with their epoxy.Then I used Gorilla glue and new luan to re-attach the outer fiberglass. It held for years and sold it without any leaks coming back.I think your approach looks good as I understand you don't have any wood (left) but all aluminum and styrofoam, so you don't have a wood problem (other than the luan) but need an adhesive that will work with the foam.My only other thought is to try and figure out where your leak was coming from in the first place. I double covered the corners and edges of that 5th wheel with Eternabond as I didn't trust sealant anymore.

I would not attach the Filon to the new luan or whatever before attaching the latter to the frame, but rather the opposite way around. Probably either could be made to work, but I think it would be easier to install and trim the inflexible panel to the framework first and then attach the outer sheathing.I would probably use construction adhesive and/or epoxy to attach the panel to the foam and framework. Rolling a luan or similar panel firmly enough to get contact adhesive to attach it to styrofoam sounds tricky at best, and impossible for a metal framework if the metal isn't perfectly smooth. Good construction adhesive, like PL-Pro, bonds very strongly.From the picture in your other thread, the framework isn't aluminum but some sort of steel. Aluminum does not rust and typically is not painted. I don't think that matters much for your repair, except for some differences in driving screws or other fasteners into the framework.

Looks like steel framing to me. Regarding delamination, I suggest you use lexan of the same thickness with holes drill randomly. Then use gorrilla glue. I know this seems like out of the box thinking but I have repaired a great deal of delamination like that. With the gorrilla glue it must be clamped completely and I have used pieces of 2x4 as wedges and a cargo bar, against my barn wall. I have sealed corners (after removing aluminum molding) with Proflex then covered with eternabond (had to be cut to width) then re-screwed on the aluminium molding with new stainless screws (Know as shutter screws in some places and they come with white painted heads)

Looks like steel framing to me. Regarding delamination, I suggest you use lexan of the same thickness as luan, with holes drilled randomly to enhance the grip. Then use gorrilla glue. I know this seems like out of the box thinking but I have repaired a great deal of delamination like that. With the gorrilla glue it must be clamped completely and I have used pieces of 2x4 as wedges and a cargo bar, against my barn wall. I have sealed corners (after removing aluminum molding) with Proflex then covered with eternabond (had to be cut to width) then re-screwed on the aluminium molding back on over the eternabond, with new stainless screws (Know as shutter screws in some places and they come with white painted heads)

Advice needed on delamination repair | Good Sam Community

Hudsoner
Explorer
Oct 20, 2016
AndyfromTucson wrote:

- Third step would be swinging the new panel out a bit, then getting under it and applying 3M 30NF Contact Adhesive (supposed to work on styrofoam) to the framing and styrofoam and the underside of the new panel, letting them dry per instructions, then pressing them together and using some sort of roller.

Any thoughts, corrections or advice?

I like your desire to use lots of 3M adhesives, because that helps to insure the continuation of my pension checks.
Just for heads up, the cross linking (curing) of the contact adhesive is initiated by the elimination of oxygen (happens when you press the two substrates together). The strength of the bonding depends a lot on the initial pressure applied to the two substrates to be bonded together. That means, the more initial pressure you are able to apply, the better the stuff sticks together in the long run.
Bumpyroad
Explorer
Oct 20, 2016
yep, if you want a permanent bond, use some of the 3 M sealants, don't want to guess at the number now, instead of "fad" stuff.
bumpy
AndyfromTucson
Explorer
Oct 21, 2016
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?
AndyfromTucson
Explorer
Oct 21, 2016
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?
Joe417
Explorer
Oct 22, 2016
Here's a picture of one that I was working on.

That's just a scrap piece of plywood with white paint on it that the clamps are pushing on. You have to have the pressure on the filon to keep the polyurethane from expanding.

Hope that makes more sense.
AndyfromTucson
Explorer
Oct 22, 2016
Thanks Joe417; A picture is worth a thousand words!
fourthclassC
Explorer
Oct 22, 2016
Really interesting. Love to see how others have handeled the situation. Let me clarify my "fix" My delam in that location was not so bad that I needed to disasemble to that extent. I peeled up the filon and removed as much bad luan as possible then buttered my hole ladden plexiglas which was cut to the right shape, with gorilla glue. My clamping involved an expanding cargo bar (from Northern tool) and several other pieces of wood and even an expanding shower curtain bar. All against my barn wall. In the case of the areas in the lower walls on the front face of the camper "box" I used the bars against a solid fence post. Required some creative parking but all have been rock solid for more then a year now.
Gjac
Explorer III
Oct 22, 2016
fourthclassC wrote:
Gorrilla glue is difficult to work with because of the swelling and the stickieness- but if fill voids to completely support panels. It will make a mess if not clamped/restrained properly (also so the clamps do not stick) But it is waterproof when dried and the correct adheasive for this application in my opinion and from my actual experience. Before I used it I contacted Gorrilla Glue company and they said the glue will last longer then the substrates I was using.
Gorilla glue or any of the polyurethane glues are messy to work with at least for me. Epoxies provide a stronger bond. The problem with these type of repairs is that if the delamination is caused by water intrusion the moisture is likely to be still be under the laminate and not many adhesives adhere well to wet surfaces. Polyurethane glues will react to the moisture and foam up making a mess when they expand and lose some of their bond strength but still be stronger than the substrate they are bonding to. Solvents like Mek or Acetone can help to remove some of this moisture before bonding. They will absorb the moisture then flash off quickly. If you can remove the outer skin like Joe showed and know the substrate is dry I would use an epoxy if you are doing a local repair like under a window that leaked and it is wet or moist underneath I would use a polyurethane. I did not remove the outer skin and used the side of a brick building to retract the pressure using car jacks. The lessen I learned was to use the leveling jacks on the MH first before applying pressure with the car jacks.
TriumphGuy
Explorer
Oct 31, 2016
Joe417 wrote:
Here's a picture of one that I was working on.

...

That's just a scrap piece of plywood with white paint on it that the clamps are pushing on. You have to have the pressure on the filon to keep the polyurethane from expanding.

Hope that makes more sense.

Great setup. I should have done something like this when I did a similar repair - I rednecked something up with the barn wall and 2x4s. But didn't get even pressure for a smooth outcome with the glue swell.

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