i used the full t2 on the foam, then cover with canvas. i know i could go out there a tear off that canvas, it will come up, it may take some of the foam off also. but i also did a layer of diluted t2/3 on top of the canvas, and then primed and painted, i can tell you that stuff is not naturally coming off. i am sure if i try i could probably pry it off, but i don't want to do that. lol so i am really happy with the sticky ability of this stuff.
i don't know if it will break down over the longterm, but i am confident it will last me this whole camping season.
i can tell you that the only place water is going to come thru is on an opening, window, door, hatch. it will not come in anywhere there is a seam. once wrapped, it becomes one solid unit.
by all means do your own testing, first of all it is sort of fun. but i did my own test, sort of. i tried to water proof with t2 a cardboard box. it worked, that was enough for me, to give this a try. my cat has since taken over my box. lol
and seriously if you think about it, this really is no more than a sandwich wood build. i see lots of folks build with a foam inside, we are still using the foam as the inside. but instead of wood on the outside, or aluminum we are using fabric for me, canvas.
i have come to the conclusion that the inside really doesn't matter. not the way mine was built. but the inside could be done so many ways. cloth, wood, carpet, anything/anyway you want.
the foamie is taking a long trip this summer in july, we are going to the crossroads gathering in indiana, i am sure some of the folks there will check out the foamie. perhaps some of them will be willing to come back here and report of the strenght. ratkitty from here, has already reported the strenght of this.
i am also, convincing myself that it will be just fine on that nose bleed bridge. mine is small enough that i know it will be just fine, it will not blow off the bridge. now my second build, which is taller, well lets say i will never cross that nose bleed bridge with the second one.
i may even take a trip down to visit gpw in that one.