After removing the raw fiberglass baffle plenum plug from the engine, it was sanded / primed and painted smooth so I could make a splash mold from it. The plug was then waxed, and sprayed with a layer of PVA mold release. The mold was made much in the same way: 6 layers of 8 oz. fiberglass cloth and polyester resin was applied to the baffle plug, and a framework was built onto the top of the new baffle mold, so it would not distort.