waikikikichan wrote:After you shape the "foam", how are you going to glass it or skin over it to get it water tight ?
Depends on the material really. Certain foams need to be fiberglassed, others need to be coated in epoxy and vacuum bagged.
If I do a fiberglass it it's as simple as cutting strips of fiberglass to the right length, laying them out in the correct pattern, coat with epoxy and let cure.
Other foams will burn with the epoxy used in fiberglass, so you have to use a different epoxy, which you have to set with a vacuum bag since there's no matrix (cloth) for it to bond to. The vacuum pump doesn't have to be real powerful and you can use stuff from home Depot to make your bag. I had a class on composite materials, it's pretty simple concept but tedious. I've got an article about the different foams here somewhere, I'll send you a link when I find it