Attaching Something to Foam Wall?

[marant]

I have a need to attach something to the foam wall by the dinette table in our 2022 21C. As best I can tell the wall consists of the foam surface, a foam backing and then the exterior fiberglass, with nothing firm like plywood into which I can attach a screw.

At this point my thought is to use velcro, though it may not be strong enough. I really do not want to use something like 'shoe goo', though that may be what I ultimately decide to use. If it is necessary I really want to be able to remove the fastening with a minimum of evidence it was ever there.

[HABBERDABBER]

What's the application? What is the device? How heavy is it?

Not doing potential damage to the covering is tough. Any adhesive you apply to the foam covering is only really attached to a thin layer of vinyl or some other coating covering. There's likely some fabric backing. Kind of like a thin naugahyde with a foam backing. That's not a structural, load carrying base for attaching things to.

If your item is lightweight, some industrial 3M Dual Lock Reclosable Fastener (like Velcro) might work. It has a thick and gummy adhesive that could be softened & removed with lighter fluid.

The adhesive could react with the foam covering coating and discolor.

[marant]

Item is not really heavy, just needs to not move.

[HABBERDABBER]

Your options, it seems to me, are limited.

[Centex]

FYI here's a cross-section of the wall covering material ETI uses (edge of a roll I ordered with my trailer). The thin vinyl and grey open-cell foam in this pic are 'bonded' when the material is manufactured (not by ETI).

On the walls in my 2021 5.0 ETI used spray adhesive to 'bond' a layer of ~1/4" black closed-cell foam to the shell interior, then spray adhesive to 'bond' the pictured wall material open cell foam to the closed-cell foam. I've observed this 'whole wall cross section' at several places where I drilled holes and cut hatches into my trailer. It can also be seen in the dinette benches at the base of the walls.

As always, yours may differ.

I won't hazard a guess about any adhesive that won't stain or damage the vinyl over the long term. Perhaps noteworthy that ETI carefully used a strip of paper under the masking tape they used to secure the pictured roll of material I ordered (no tape adhesive in contact with the vinyl surface). I have seen build pics where they apparently used painter's tape directly on the vinyl walls temporarily.

All just FYI / FWIW, Good Luck and Have Fun!

[hugh]

I mounted some moderately heavy decorations to the wall in our camper using double sided "mounting tape":

https://www.amazon.com/Gorilla-60360.../dp/B07LFRN1K8

I cleaned the area with some rubbing alcohol before applying, and it hasn't come loose yet.

I expect over time that will lead to some discoloration, but I'm not trying to keep the trailer pristine for the next 100 years..

[Vermilye]

If it can hang from a hook, the 3M Command system might work. I have a couple of 6"x8" indoor/outdoor thermometer displays attached to the "wood" walls using the Command hooks & FunTac to keep it from rocking. No idea if it would work on the vinyl...

[homebrewer]

Originally Posted by marant

I have a need to attach something to the foam wall by the dinette table in our 2022 21C. As best I can tell the wall consists of the foam surface, a foam backing and then the exterior fiberglass, with nothing firm like plywood into which I can attach a screw.

At this point my thought is to use velcro, though it may not be strong enough. I really do not want to use something like 'shoe goo', though that may be what I ultimately decide to use. If it is necessary I really want to be able to remove the fastening with a minimum of evidence it was ever there.

Your design requirement "to be able to remove with minimum evidence" conflicts with "strong enough" - you can't attach something to the foam covering the wall and meet these requirements. I mounted a fairly heavy Dickinson heater by cutting away the foam and attaching a wood strip to the fiberglass behind the foam with fiberglass resin and glass mat. If you cut the piece of wood to hide the edge of the cut into the foam, letting it stand out from the wall, it makes a nice piece of trim that can be used to attach anything, no matter how heavy. If you look behind or under the construction of the fiberglass walls, this is how ETI made some portions of the trailers. I prefer to hang thing from the cabinets or attach things to the bulkhead walls so you can use screws, but if I want something to go on the white foam wall, I'll use the fiberglass again.

[Jim Bennett]

If it is very light a Command Hood would work just fine. A bit heavy I would worry about the stress it would put on the vinyl possibly causing a wrinkle. In mounting a surface light on the ceiling in my 19 I cut a hole in the vinyl and foam smaller than the light and big enough to accept the mounting screws and epoxied a 1/2" piece of plywood to the shell. Worked great but this is only good for permanently mounted items. I guess on a wall you could cover it later with a nice picture.

Here is a photo using a fish tape to pull wires through from the fan.

[occer]

I experimented with the sample ETI sent us when we asked for samples of the different wood, flooring, Formica and such.
I tried command strips, contact cement, double sided tape. The double sided tape stuck the best.. After a few weeks the vinyl swelled / puckered a little with the command strip and double sided tape. Decided to not hang / mount anything to the vinyl.

[HABBERDABBER]

The OP has never stated what item he wants to secure to the foam liner. It's hard to advise with incomplete information.

[MyronL]

My first thought when adding shelves, hooks, etc., to the walls is to avoid doing something that is not reversable. There are ways to attach these things and not do damage to the vinyl.

[C&G in FL]

Originally Posted by HABBERDABBER

The OP has never stated what item he wants to secure to the foam liner. It's hard to advise with incomplete information.

Perhaps the item is related to a medical condition that the OP is hesitant to disclose or something similar, and in reality, if that is the case it really is nobody’s business what he wants to hang. The OP is only asking how to hang something to the vinyl.

[Ron in BC]

Originally Posted by C&G in FL

Perhaps the item is related to a medical condition that the OP is hesitant to disclose or something similar, and in reality, if that is the case it really is nobody’s business what he wants to hang. The OP is only asking how to hang something to the vinyl.

Without knowing the weight and specific location it's difficult to give good advice.

Ron

[C&G in FL]

Originally Posted by Ron in BC

Without knowing the weight and specific location it's difficult to give good advice.

Ron

I realize that, but if you have read the thread from the start he did not disclose what the item is in two posts, even after being asked what it is after his initial post. I see that as an indication he does not want to say. Maybe he is embarrassed, or maybe some other reason. Others have made suggestions without knowing what the item is. While I agree with you Ron, he did say it was only temporary if I interpreted his post correctly but I really don’t think he wants to reveal whatever it is he wants to hang. And if that is the case, then he is to blame for not getting good advice, and as I said before, my philosophy is that nobody should be pressing him to disclose.

[HABBERDABBER]

Good luck attaching something to the foam liner, whatever it may be.
I've said my piece, and advice.
Yeesh!

[Dave Miller]

Originally Posted by MyronL

My first thought when adding shelves, hooks, etc., to the walls is to avoid doing something that is not reversable. There are ways to attach these things and not do damage to the vinyl.

This has been my approach as well. Hang it from an overhead cabinet, etc. I’ve refused my wife’s requests to attach to the vinyl wall material.

Nice mods!