How to Fiberglass Over Metalby Jay Kurz
Fiberglass consists of fiberglass mat that is saturated with a fiberglass resin. The fiberglass resin is a thick substance that needs a catalyst to harden. Fiberglass is a very durable material that will bond to almost any surface, including plastic, metal, wood and Styrofoam. For laying up fiberglass on hard materials such as metal it's important to thoroughly scuff the surface to get a strong bond. All fiberglass materials can be found at your local auto parts supply store or at a marine supply store.
Grind the area of the metal that will be getting fiberglass applied to it using an air grinder. Scuff the entire area, removing any loose or damaged metal down to solid metal.
Wipe the ground area of the metal clean with a rag and acetone. Thoroughly clean the area until the rag no longer pulls up any dirt. Let the acetone dry.
Lay the fiberglass mat on a hard surface and cut it to size using a razor knife. The size and number of layers will be determined by the specific job you are doing.
Pour the fiberglass resin into a small bucket and add the recommended amount of catalyst, according to the container's instructions. Stir the resin and catalyst together with a stir stick until the fiberglass is one consistent color. After the fiberglass is mixed you have about 20 to 30 minutes until it completely hardens.
Wet the surface of the ground metal with the resin mixture using a 4-inch felt roller. Apply the first layer of mat to the surface and saturate it with resin using the felt roller. Remove any air bubbles and flatten the mat with an air roller. Add the remaining layers of mat following the same process for each layer. Let the fiberglass harden.
Put on a respirator and sand the fiberglass smooth using an electric sander with 200-grit sandpaper.
- Wear a respirator when working with fiberglass materials.
Items you will need
- Safety glasses
- Air grinder
- Grinding disc
- Fiberglass mat
- Razor knife
- Fiberglass resin
- Small bucket
- Stir stick
- Felt roller
- Air roller
- Electric sander
- 200-grit sandpaper
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