Mark,

Lot's of advice so far... and all of it bad. From someone in the composites
industry, there are serious drawbacks with each homebrew "mold release"
material mentioned, except PVA. Find the local FRP materials supplier and get a
can of basic mold release paste wax. It makes no sense to invest all the time
and effort in your project and then try to save $7 by using some doubtful
concoction for mold release.

Bob