I've never used the bedsheet and paint on a whole camper yet but I've seen it done on a standy. with the boxes it works great. I cut the wood and assemble it with duct tape than hot glue the seams on the inside remove the tape and paint the box work the bedsheet into the paint than add a couple of more coats and they seal up good and are strong. I have 2 that have dutch ovens in them and two that we just fill up with stuff to take with us.
The problem with using latex paint or epoxy and bed sheet on just foam isn't the lateral strength but the penetration strength, A road rock or stick could go right through it. That's why I'm playing with the felt hoping that it will work like fiberglass matt to add some penetration resistance.
By the way where are you getting the frp. Colaw's in Joplin Mo has it on rolls I think it is 8' wide and about $12 a running foot. That would be quite a drive but I think that they would ship it.
http://www.colawrvsalvage.com/
They don't list it but email them for a parts search Ron is the guy I've talked to.
Gary
Where ever we raise the hatch is home.
Darn blank states keep getting further away and we keep traveling slower ain't never gona get this map full.

