Before this post, the car had no floor underneath the occupants’s feet. An aluminum underbody will be attached, but it will be too thin to support the weight of heels resting on the floor. So, two floor panels were constructed from fiberglass and epoxy resin and secured in the vehicle. To start, two mirrored mold plugs were made from lumber and eighth-inch particleboard. Since the A-side is the inner face of the part (facing up towards the occupant), only a male mold needed to be made. The floor panels have three sides, intersecting at one vertex. So three separate sheets of particle board were glued to a two-by-four base.
After a rough sanding on the corners, body filler was mixed and applied to fill in the small gaps between the boards. This was again rough sanded with 120-grit to remove excess material. More filler was applied and sanded until the gaps were completely filled and the transitions were smooth.
Then, finer 240-grit sandpaper was used to smooth the fibers and prepare the surface for painting. Two coats of gray primer were applied. Then, the entire molds were sanded again with 240 and then 360. Finally, the molds were painted with two coats of black enamel to prepare them for waxing.
Mold-release wax was applied over the entire molds, allowed to haze, and then buffed off with a rag. This was repeated four more times to completely seal the molds and prevent adhesion of the resin. Then, two thin coats of PVA mold-release film were sprayed onto the molds using an HVLP gun. This water-soluble liquid dries into a thin, green film with weak internal attractions, allowing it to tear easily when attempting to part the workpiece and mold. From here, the layup process began. Three plies of midweight fiberglass cloth were used, with a schedule of 0-45-0 degrees. Between the second and third layers, eighth-inch plywood pieces were added to act as a core material. Using plywood adds a lot of strength to the part without adding much weight and lessens the plies of fiberglass required, bringing the total cost down. After an overnight cure, the floor panels were removed from the molds. One parted easily while the other brought along some chunks of fiberboard. A little acetone dissolved it away easily.
The angle grinder was used to trim the perimeter of the parts and to make cutouts for the seat belt bracket and part of the frame. The panels were test-fit into the car and hoels were drilled for mounting. After a thorough washing and brief sanding, two coats of black epoxy enamel were applied to the panels.
PH-571 