what method should i use to build out a camper top?
i'm putting a 'penthouse' sleeping shell on the top of my chevy astro van. i got a truck canopy, cut it in half, and i'll be joining the two halves to make a room to sit up there. i have to build out the front of the room, and i'm going round and round about how to do it. i could use wood, plywood and stringers, but that presents problems with joining the wood, weight, and the funky look. i've thought about making a frame out of 1/2 conduit, and filling in the space with 2 in plastic foam they use to insulate houses- it would be easy to cut to fill in curvy/complex shapes. but how do i 'glue' them together? the build out will extend a little over the windshield of the van, to give me more room and make something artsy... it IS an art car. if i used foam pieces, i could skin it over with fiberglass to make it a little rigid and watertight. but i've never seen it done.
any other ideas???? imagine that big boxy open space at the front becomes a kind of "nose" shape. how to do that? and maybe include some windows so i'm not all claustrophic'd in there...?? needs to be cheap materials, water-proofable and sturdy enough to not fly away. TIA!
of course, i'll be documenting the build for an instructrable. see: http://picasaweb.google.com/thaikarl/PuttingAPenthouseOnTheRocketVan#