Guys, what I'm talking about is liquid. You mix two parts to activate it, then it expands.
The foam is rigid when it hardens. It can be sanded and shaped to make molds for fiberglass.
When I was building S.C.C.A race car bodies we would use it to make a buck, then make the part in glass.
then if we were happy with the new fiberglass part we would make a mold of that part so we could mass produce.
Poly urethane foam comes in 1/2 lb 2 lb 4 lb 6 and 8 lb densities .
The denser the foam the less cubic feet of foam it produces.
Thus the less dense it is, it has more and larger bubbles( air pockets) in it and produces more cubic feet.
In race cars section of the body is filled with this foam because is also impact foam and very light as well.
I can also be used in boats because it floats.
I figured someone here has used it for fiberglass here and had a supplier.
My local supplier in Kansas City has closed his business.
Now I am paying 50.00 for a gallon that produces 6 cubic feet at the most.
I was paying 50.00 for five gallons of it