How to Make a Body Kit

Body kits add a personal touch to a car. They usually come in the form of stylized front or rear bumpers or spoilers on the trunk or hood. These accessories are popular on racing cars, as people believe that they can improve aerodynamics. Designing and making body kits is a long, difficult process that involves constructing body parts out of plastic or fiberglass to fit on a specific model of vehicle. Making such parts is a task that may be best left to an auto expert, if at all possible; but if not, follow these directions to make your own body kit.

Difficulty: Challenging

Instructions

Things You'll Need:

• Urethane foam
• Moldable plastic
• Foam-cutting knife
• Belt sander
• Fiberglass sheets
• Laminate resin
• Metal/concrete mold
• Large oven

1. Measure the space on your vehicle where the body kit will go. If you're replacing the stock bumpers with customized ones, take down its dimensions so the new bumper will fit in place. A customized side panel must fit on the door or between the fenders. For a front or rear spoiler, measure the hood or trunk so you can center the completed piece on top of it.

2. Design and plan out what your body kit will look like. Start out with drawings and sketches on paper. If you have computer animation software, you can then design the part in full 3-D animation. Recording the exact measurements and dimensions of the body kit parts is essential.

3. Create a mold that will shape the kit parts. For fiberglass parts, use large blocks of urethane foam. Cut them into the correct shape, then sand or whittle it to a smaller shape that the fiberglass layers will fit onto. Plastic kits will require a convex mold carved from concrete, metal or other tough substance. Such a mold is often more expensive and difficult to deal with than having a professional do it.

4. Construct the kit parts. Lay fiberglass sheets over the foam mold and coat the sheet with a laminate resin. Repeat the process two or three times and make sure there is an airtight seal across the entire mold. For plastic parts, heat the plastic in an oven, pour it into the mold and let it cool into the shape of your body kit.

5. Paint and detail the kit once it's complete. You can paint it before or after installing it on the car. Apply a coat of primer before the actual paint, which should be multiple coats applied in even, level strokes.

6. Attach the kit to the car. Bumpers will be attached the same way the stock bumpers were connected, so make sure you know how the older bumper was affixed. A spoiler should be bolted on or sealed with a strong adhesive. Make sure this part is centered between the sides of the car, or it won't look good.

Tips & Warnings

• If you use plastic, make sure you know the properties of the type you are using. Acrylinitrile Butadiene Styrene is commonly used for body kits. It must be heated to more than 250 degrees F to be shaped.

Resources

• Car Body Kits and Parts