by Finlander » Fri Sep 25, 2020 8:39 pm
Thanks for the input! We have gorilla glue (the brown stuff). Another option I was thinking about is using some sort of construction glue like sikaflex, that I could spread thinly with a plastic scraper on the complete surface where XPS would be attached, but I always run into the concern will it dry also in the middle or stay moist and ruin the plywood. I remember reading here or seeing a clip on youtube about a guy experimenting, and some glues didn't dry in the middle, but I just can't seem to find that now to watch it again.
The idea was to build the walls in a horizontal plane before attaching them to the floor of the trailer, so I can just use weights to clamp the glued XPS pieces to the plywood outer skin of 6,5mm birch plywood. Also some stick framing (pine) will be added around the edges of the walls, so the camper's outer shell of plywood will be held together wood to wood, TB2 and nailgun. This means that I don't have to rely on the glued XPS to actually hold the camper together, but it should help make the walls rigid together with the simple stick framing, as the 6,5mm plywood alone is quite flimsy. There will also be wood framing around windows, door and bulkhead. So the panels won't be very large. We don't have 4x8 sheets of XPS, only 2x8.
Btw, the XPS in the walls will be either 30mm or 40mm thick.
/KT