Post #241947 by Gigantalope on Sun, Jul 9, 2006 10:23 PM

a chain of stores called TAP plastics makes a two part foam originally developed to pour in the hollow recess of fibreglass boats. Once you mix them, it turns mocha colored, and foams then turns solid.
http://www.tapplastics.com/

I belive it's a urathane base...

the nice thing about it is you can plan how much you need...by the volume of the container you pour it into.

It's messy as hell to carve, but gives a pretty good volcanic stone look.