The gelcoat protects the fiberglass and maintains a shiny surface. A gelcoat is often used to protect the hull of a boat. With wear, the fiberglass gelcoat must be replaced. You can buy gelcoat from the boat manufacturer or at a related supply store. This article explains how to coat fiberglass with gelcoat.
Steps
Step 1. Remove the old gelcoat layers
- Apply a compound to the fiberglass to polish or remove oxidation. Spread with a sponge or abrasive pad.
- Wash the fiberglass with water.
- Let the fiberglass dry.
Step 2. Clean the fiberglass
Remove paint or primer from the fiberglass surface. Use a paint scraper to do this.
Step 3. Apply polyester, or better yet, a vinyl ester primer or filler
- Coat the fiberglass with 2-3 coats of resin using a sponge roller. The layers should be very thin.
- Apply each new coat of resin to a wider area of the fiberglass than the previous coat.
- Place a heating lamp next to the treated area.
- Let the area dry.
Step 4. Wash the fiberglass
- Work over the fiberglass surface with an abrasive sponge and water.
- Let the fiberglass dry.
Step 5. Sand the fiberglass with sandpaper
Use sandpaper to smooth the surface of the fiberglass.
Step 6. Add color to the gelcoat
Mix the desired gelcoat pigment with the gelcoat to match the original shade. Follow the directions for your specific pigment and gelcoat brand.
Step 7. Fill the spray bottle
- Strain the tinted gel coat through a paper filter.
- Pour gelcoat into a spray bottle.
Step 8. Apply gelcoat
- Using a spray gun, apply a thin layer of gelcoat to the desired area of the fiberglass.
- Wait a few minutes for the coating to settle.
- Repeat the spraying process (remembering to wait for the layer to settle) of the gelcoat on the fiberglass at least 5 times.
- Cover larger areas with new layers of gelcoat.
- Apply enough coats of gelcoat so that you cannot distinguish between treated and untreated areas of the fiberglass.
Step 9. Allow the gelcoat for 48 hours to properly bond to the fiberglass
Step 10. Sand the fiberglass with sandpaper
Use sandpaper to smooth the surface.
Step 11. Buff the fiberglass
- Use a sponge or abrasive for polishing and white polish.
- Apply fine sanding compound to the polished fiberglass surface using a sponge or abrasive.
Step 12. Wax up the fiberglass
- Apply wax to the treated fiberglass with a sponge or cloth. Rub in the wax in a circular motion.
- Let the wax dry.
- Wipe the waxed area with a soft cloth to give the surface a shine.