Half-inch MDF was cut to the desired shape and routed. These became the mounting flange for the speakers. To secure each speaker to the baffle, 81/432 T-nut fasteners were mounted into the panel. The sanded panel shown here is ready to test-fit in the car. To form a mold for our structure, green foam was cut to the desired shape and glued to the foil. Once fully cured, the panel was unbolted from the car and taped.
In preparation for fiberglass, the side panel area was completely taped off with 3M 233+ masking tape. This tape is an ideal choice because it doesn't leave any sticky residue inside the car. Fiberglass mat and resin was carefully applied to the mold. To smooth out the panel, our table was set up for the application of Rage Gold body filler (www.evercoat.com). I completely coated the panel with body filler and let it cure. Before placing the panel in the vehicle, I first test-fit the 6.5" speakers for proper fit. The tape was covered with 3M Super 77 spray adhesive and aluminum foil.
For strength, a total of six layers of 1.5-ounce fiberglass mat were applied. Using 36-grit paper, I hand-sanded the body filler to remove any high spots. Once the foil was laid, an MDF exoskeleton was framed inside the car and glued together. The side panels were then carefully bolted into the vehicle to assure proper fitment. The newly formed side panels were allowed to cure in the car for 30 days.