That EVA foam looks like a great idea. I was toying with using ply strips for the structure, and lycra to bridge the gaps, to support fiberglass as it sets (a bit like the wheel arch extensions from Project Binky). I was worried it would turn out very ridge-y, and end up looking like an old-school canvas canoe. Thin sheets of EVA looks like a much more forgiving option.
Well that works rather well.
Excellent idea, I wonder how tight a radius it would form?
You can get the foam in all sorts of shapes and sizes... rounded edge, triangle, tubes, balls... so looks like you can epoxy it into pretty much any radius you like, depending on how thick a sheet you get.
I've had a quick look around and it seems some people have problems with the epoxy not setting when applied as just a thin layer over the foam, but it looks like they may have spread the epoxy too thinly (without any glass in), and the foam doesnt appear to absorb the epoxy, so there's just not enough depth to cure properly. I'm not sure if this means it's going to be a better option to cover the foam in packing tape (so the epoxy doesnt stick at all) and just use it kinda like a buck, which will peel off from the inside, giving you a nice rigid 'glass shape that can be bonded in place and reinforced on the inside... or do it without the tape and leave the foam in place to act as a vibration dampener too. I think maybe it depends if it soaks up water or not... wouldn't want to create a wicking layer which never dries out.