Mold for Fiberglass Fuse/wings

[gsr916]

I am wanting to make a mold out of balsawood, and somehow from that turn it into an exact replica made of expanding foam.... I guess what I am asking is if anyone knows of any products I can use to make a shell from my balsawood mold, from which i can make a foam mold.

I plan to vacuum bag carbon onto the foam mold... getting the foam mold is my current challenge...

[pd1]

I tried a few years back, but I ran into some problems.
1. I coudn't get the foam to expand evenly
2. There was a lot of voids after the foam expanded.
3. I couln't get a good release agent to allow for clean separation.

I was successfull with fiberglass.
1 I finished the plug with automotive primer, sanded and painted, and rubbed to high
gloss
2 Used PVA (poly vynal alcohol) as release agent obtained at boat repair shop.
3. made mold with fiberglass cloth and matting with plywood re enforcing to maintain
shape.
4 re finished inside of completed mold automotive primer, rubbed and waxed
5. started over to make final fuse and wing shells.

You could probably save some work if you can find some sort of rubber based material for mold. If I haven't scared you off and if I can be of help, PM me. Paul
here's a few pictures.