How to Make a Fiberglass Spoiler

Design a spoiler based on your favorite car.

A fiberglass spoiler adds a sporty look to your vehicle, which could increase its value. If you design the spoiler appropriately, it could make your vehicle more aerodynamic and improve its fuel efficiency. An auto body specialist can craft a fiberglass spoiler for you, but you'll end up paying hundreds of dollars. Make one yourself for a fraction of the cost.

Things You'll Need

• Drywall mask
• Medium-density fiberboard
• Pencil
• Wood saw
• Wood glue
• Fleece
• Staple gun
• Latex gloves
• Plastic bowl
• Paint stick
• Fiberglass resin
• Paintbrush
• Fiberglass mat
• 400-grit sandpaper
• Automotive primer
• 1200-grit sandpaper
• Automotive paint

Instructions

1. Draw the spoiler shape onto the medium-density fiberboard, or MDF. You'll typically need three pieces for the spoiler: the top and the two supporting joints that attach to the vehicle.

2. Put on your drywall mask and cut out the spoiler shapes from the MDF.

3. Glue the cut-outs together with wood glue to form the spoiler frame. Allow the glue to dry for about one hour.

4. Place the fleece over the spoiler frame and staple it in place with a staple gun. Stretch the fleece as you staple to ensure it is taught against the frame.

5. Put on latex gloves and mix the fiberglass resin in a large plastic bowl according to the directions that come with the product.

6. Apply a 1/8-inch layer of resin to the entire surface of the spoiler frame with a paintbrush.

7. Allow the resin to dry for two hours.

8. Put on the latex gloves and apply a thin layer of resin to the spoiler frame. Immediately place a piece of fiberglass mat over the resin and mold it to the spoiler with your hands. Apply another thin layer of resin over the fiberglass mat.

9. Continue brushing the frame with resin, placing mat over the resin and molding the mat to the frame until the entire surface is covered in a smooth layer of fiberglass mat. Allow the mat layer to dry for about two hours.

10. Apply at least four more fiberglass mat layers to the spoiler using the same method outlined in Steps 8 and 9.

11. Smooth the top layer of fiberglass mat with 400-grit sandpaper.

12. Spray two coats of automotive primer over the spoiler. Allow each coat to completely dry before you start the next.

13. Smooth the second layer of primer with 1200-grit sandpaper.

14. Spray three coats of automotive paint over the surface of the spoiler. Allow each layer of paint to completely dry before you begin the next.

References

• Car Data: Why a Spoiler for Your Car?
• Explorer Forum: A Step by Step Guide to Creating with Fiberglass