After the resin cures, I like to let the new mold sit untouched on the plug for a few days. Letting the mold sit for a few days prior to de-molding helps prevent warping of the mold. In this case, my plug is of a long, thin fender and has a much greater chance of undergoing a noticeable warp then some of my other projects so I am more careful at this stage then usual.
De-molding the fender becomes an easy task. The PVA and wax layers were not breached and as soon as I began to pull one corner of the fender plug loose the entire mold separated from the plug. Just as planned – so far.
The next step in a project like this is to clean up the new mold of any defects or sharp edges around the flange areas. I begin by using a rag and water to remove the PVA from the inside of the mold. The result of my cleaning reveals a perfect molding surface. Had I found any defects, I would have filled them with bondo, sanded them smooth and then thoroughly waxed over them before molding any parts.
In order to make my first parts with this mold I begin by applying several (four) coats of mold release wax to my mold’s surface. When the wax has dried and has been polished to a smooth shiny finish, I apply two coats of PVA with a foam brush. On larger projects I will use my air gun but this project didn’t warrant that much hassle. In this case, I applied a light PVA coat, allowed it to fully dry, then applied a second coat for extra protection. With both the PVA and the wax applications I made sure to cover any areas of my mold, including the flanges that were formed over the parting plane. This will insure that my parts don’t get stuck on the mold.
