How to Use Foam Board & Fiberglass to Build a Car Body

Damaged body panels can make your car less appealing and even hurt your fuel economy. Dented body panels can reduce your aerodynamic efficiency and create more drag which makes your engine work harder. You can replace the damaged panels with home made fiberglass car body panel. Working with fiber glass is a laborious task which requires a lot of patience. However, making your own fiberglass car body panels can save you a lot of money and can even improve the performance of your car.

Instructions

1

Carefully sketch the design and dimensions of your car's body panels on a piece of paper. You can customize it a little bit if you wish, however you need to be certain that the panels will fit. Your drawings should also include where the panels will connect to the car. Any miscalculations will result is your piece being unusable.

2

Using your drawing as a guide, carve out the foam blocks to your exact specifications. You can use a knife or any other tools required to make the mold. The carving should be the mirror effect of your part. After you have roughly carved the foam, sand it until smooth. Cover the foam in Bondo and wait until completely dried. Use 180-grit sandpaper to smooth out the Bondo.

3

Cover the Bondo in the polyester primer. The primer should be very thick and made specially for molds. Allow it to dry thoroughly before sanding. Use 180-grit sandpaper to completely smooth out the primer. Repeat with finer grits until you reach a 1000-grit wet sand. The texture of the mold will be the same texture your body panel will have.

4

Polish the mold to a high gloss and allow it to sit for 3-4 days. During that time period, wax the piece 3-4 times. The wax will seal up any of the pores in the primer. Spray with Tooling Gel and allow it to sit until tacky. Once the gel is tacky, apply the resin.

5

Separate the fiberglass sheet into small pieces. This will prevent any fiberglass imprints onto your final product. Lay the fiberglass pieces onto the resin and allow for it to soak in. Use the fiberglass roller to remove any trapped air bubbles underneath. Repeat the process 6 times to ensure a durable body panel.

6

Allow the resin to dry for a few days before attempting to remove. You may use a knife or a razor blade to clean up any protruding bits of glass. Use the wooden mixing stick to gently peel the panel out of the mold. You can use an air gun to blow in between to speed up the process.