How To Repair A Hole in Fiberglass

Fiberglass has long been known for its durability and ease of use. It is water resistant and fire resistant and can withstand the corrosive nature of most harsh chemicals. In addition, the product is very lightweight, making it easy to install. Despite its strength, however, after extended use, fiberglass can become brittle, making it susceptible to holes and cracks. While the process of repairing a hole in fiberglass requires several steps to complete, it is a task that an accomplished handyman can tackle.

Things You'll Need

• Newspaper Rags Fiberglass repair kit Putty knife Marine plastic filler Gel coat 60- or 80-grit sandpaper 220-, 320- and 400-grit wet / dry sandpaper Colorant Rubber gloves Small paint brush Plastic wrap

Instructions

1. Sand the hole and surrounding surface about two inches out from hole using 60- or 80-grit sandpaper.

2. Read instructions accompanying the fiberglass repair kit. The kit will include fiberglass resin, hardener and fiberglass cloth. A kit can be purchased at your local hardware store.

3. Cut three patches from the fiberglass cloth. The first patch should be cut a few inches smaller than the hole opening. Cut the remaining two patches progressively smaller than the first patch.

4. Mix the fiberglass resin and hardener according to the instructions.

5. Soak patches in the resin/hardener mixture until completely saturated.

6. Cover the hole opening with the smallest patch. Layer the remaining two patches from smallest to largest over the first patch. Let area dry overnight.

7. Sand the dried patches with 60- or 80-grit sandpaper. Wipe the area clean with a damp rag.

8. Spread the marine plastic filler in an even layer over the dried patches using a putty knife. Allow the area to dry at least 30 minutes.

9. Use a 60- to 80-grit sandpaper to blend the filler into the surrounding fiberglass surface. Wipe the area clean with a damp rag.

10. Apply a 1/8 inch thick layer of gel coat over the dried and sanded filler using a small paint brush.

11. Cover gel coat with plastic wrap and allow to cure overnight.

12. Wet sand the dried gel coat using 200-grit sandpaper. Wipe sanding residue from area with a damp rag. Use the same sanding process with both 320- and then 400-grit sandpaper to further blend the patch into the surrounding surface.

Tips & Warnings

• Spread newspaper over work surface to protect area from spills. Tint the gel coat with a colorant if it does not match the fiberglass surface. Refer to colorant packaging for instructions.

• Wear rubber gloves when working with fiberglass patching chemicals. Open a window or turn on a fan before beginning for proper ventilation.