good question. i never thought of that. i do custom body work on autos with fiberglass. that would be kinda cool to do i think, and i can make it as wicked as i like. just need to find a cardboard box the right size to lay sheets over. i dont know though about the chemicals. maybe someone can shine some light. i think if ya made it around a cardboard box, cut out your window once its dry, rip the box out, lay some bondo inside, paint with a chemical resistant epoxy inside and out *white*, let air dry for about 2 weeks, smell for chemical presence then add windows, light, heat and get temps stable. that should work. thanks for the idea! i hate wood, im not bob the builder. i suck with all that, but i'm real good with fiberglass. i know what im doing very soon