foam / styrene to shell?

Equipment Proton Packs
1

http://www.smooth-on.com/a129/Introducing-NEW-Epsilon%3D-EPS-Foam-Coating!/article_info.html

Imagine taking a foam pack, coating the outside with this stuff and then fiber glassing overtop of it for added strength (If needed). Flipping it over and disolving the foam with something (Laquer thinner, gas, etc.) . That would leave you with a mold. Spray with mold release, gel coat, then fiberglass. Then you could pull a fiberglass shell from it…What do you think?

I think it would save a ton of money over mold rubber, clay, etc at $90 a gallon. If it worked, my only concern would be how many shells you could pull before having to remake the mold. Just a thought though. I don’t have the $$$ flow to try it.

2

wouldn’t work. You need a flexible material for a mold. That stuff is intended as a quick way to hardcoat foam sculptures instead of pulling a mold from it and casting in fiberglass. Not as durable but faster if you just need something to last a short time.

3

There was a group in one of my design classes that proposed a similar method to lay up composite wings. The issue is, there’s no guarantee that what you use to dissolve the foam won’t eat into what you want to use as a mold. Along with that, the fumes and disposal of the waste you’ll generate, I’d say it a bit on the dangerous side. And then there’s the point above, where you should never cast hard material into a hard shell.