I'll be honest, I've never built a foamy. But I do like the idea. Would you foamy experts please tell me if this would be practical. Would it be possible to build a sandwich with 1/8 plywood on either side of a piece of foam board to use for the walls and side profile? Cutting windows and doors and the side profile in such a glued up sandwich would be a piece of cake. A router template would make cutting out the spar fittings for the roof practically a no brainer. Wouldn't the walls be strong enough to hold/mount conventional spars made out of 1X1 Pine and then simply cover with roof with 1/8 plywood with pieced foam board for insulation, working from the inside out? The wiring could all be run through the roof construction part of the tear drop and be located in the galley area without any channels needing to be cut in the sidewalls. I mean glued sandwich sideboards ought to be really strong enough for anything mother nature could throw at it. Such a unit could be covered with poor man's fiber glass or even aluminum. When I built my TD I built heavy because I take the thing off and use the trailer for other things at least once a year. I actually built in a fiberglass base sled to make siding my TD off easier. I built like a tank and problem is my unit tows like a tank. After reading about the virtues of foam I have to wonder if perhaps I couldn't have gone another route. The foam would be cheaper than the 3/4 plywood that I used for walls and I wouldn't run into that pesky frost action that I get during really cold temperatures which is when I primarily use my current TD, where I've only got wood making up my sidewall. (the way I built my walls, there are places where only wood on top of wood makes up the wall. The insulation is patched in next to it which is really not a great thing in really cold temps below 0 F). I would think between the 1/8 plywood inner lining wall along with the foam board would support both roof and anything I would ever be carrying in my galley shelves. For those of you that have built with foam what are your thoughts? It could be that I am overestimating the strength of a composite foam sidewall.
Art