The outer gelcoat finish on a fiberglass boat is a porous resin material that protects the hull and gives the boat its shine. Time and exposure to the elements will eventually erode the relatively soft surface of gelcoat, leaving your previously shiny hull looking dull and chalky and fading the boat's colors. To bring back the color and shine to your boat, you must go beyond a simple wash and wax. With a few simple products and a lot of elbow grease, you can restore the shine and vibrant color to your fiberglass boat.
Mix 5 cups of mild liquid detergent with 5 gallons of fresh water in a 5-gallon bucket. Wash the boat with this mixture using clean cloths and lots of water.
Put on rubber kitchen gloves and safety glasses. Dampen a clean cloth with acetone and fold the cloth into quarters. This is the de-greasing part of the project, to remove the mold release wax being exuded by the gel coat, so as you wipe down the hull, refold the cloth as necessary to ensure you're wiping with acetone and not a dry cloth. Re-wet the cloth as necessary.
Apply about 1 tbsp. of polishing compound to another clean cloth and begin wiping it onto a 3- by 3-ft. area of the boat in overlapping strokes to ensure a thin, uniform layer of polishing compound is on the surface. When the area is covered, polish it with an electric buffer and polishing pad until the oxidized surface layers are gone and the color begins to return. Continue polishing the boat, one 3- by 3-ft. area at a time.
Wax the boat with automotive paste wax in overlapping circular strokes, using a clean cloth, working in 3- by 3-ft. areas. As you complete one area, apply wax to another area until the whole boat is waxed.
Allow the wax to form a haze. Buff the wax with an electric buffer and a buffing pad, using circular motions.
- Repeating this process once every season or two ensures your boat's colors will remain more vibrant; the wax also adds another layer of protection to the surface of the boat.
- BoatUS Boat Tech: Restoring the Shine to Fiberglass
- "The Complete Book of Boat Maintenance and Repair"; D. Kendall; 1975