Hey all,
I am trying to make a mould for a certain carbon fiber part that has been designed using CAD software. Traditionally, polystyrene foam has been used -a negative mould is made in the foam using a CNC cutter, and the surface of the mould is then prepared using layers of epoxy and bondo. The top layer has always been a hand-sanded super-smooth layer of epoxy. Given the amount of labour involved, I am looking for alternative methods.
Specifically, my idea was to use the CNC to cut the part itself out of the polystyrene foam such that I have a positive mould, which I would then coat with a thin layer of epoxy. I then intend to use the Uni-Mould system, treating the epoxy-covered foam as a regular part, to obtain a negative mould. Any suggestions or reasons this would not work? I am especially concerned about the layer of epoxy on the polystyrene foam reacting with the epoxy-based gelcoat and hindering its release.