We are doing some remodel work on a client's motorhome. Part of the process requires laminating Extruded Polystyrene Foam (XPS, the pink stuff) to luan in large areas (think wall-sized pieces). This will improve both the R-value and the sound-reduction properties of the exterior walls.

Here is a description of the project.

We are removing the original vinyl wallpaper in the motorhome. We are using a heat gun and a scraper. The wallpaper is coming off easily, but leaving a sticky residue. Since the original wallpaper is wrinkled in areas, and there has been some water damage behind it, the paper needs to go. Leaving the old wallpaper in place is not a viable option.

After any wall repairs are made, we then need to glue XPS foam board to the existing luan wall in the motorhome and glue a new sheet of luan on top of that. After all of the new walls are complete, new wallpaper will be added as a separate step.

Once the walls are complete, we can get back to what we do best: cabinet-making and installation. :-)

We need to find the appropriate adhesive. We did find some info about a dap water-based contact cement, but many reviews raised some negative concerns regarding its performance.

Does anyone have any adhesive recommendations and/or experience with adhering sheet foam to wood?

We layup 2" xps with hardboard and ply skins that then go on the CNC. The only options we have found is water based contact, PVA, gorilla glue, and there is a foam specific construction adhesive from loctite.

The loctite option is in caulking tubes and takes a ton for decent coverage and slow to dry long clamp time. All other than the contact are tough to clamp as the foam is never flat/uniform.

We are having a difficult time finding a water based contact cement.

Is there a specific brand of water based contact cement that works well?

Most any of the non-flammables are water. DAP/Weldwood, Formica, Wurth Brand, Wilsonart.

I have laminated polystyrene panels to luan ply with 3M Fastbond 30 NF water-based contact cement. I applied 2 coats to each surface, and pressed them in a vacuum bag.
However, I think that it would work in your application, if you could find a way to put sufficient pressure on the panels.
Also, be aware that water-based contact cement is temperature-sensitive, so you wouldn't want the work area to be too cold. See the specs for details.
Rick W

Maybe im over simplifying it, but could you use expanding foam? Some kinds don't expand as much. Then again maybe a bad idea. Ive seen insulated concrete forming blocks bonded this way to each other

The loctite option is in caulking tubes and takes a ton for decent coverage and slow to dry long clamp time.