Things You'll Need
Liquid dish soap
Fiberglass filler kit
360-grit wet/dry sandpaper
1200-grit wet sandpaper
Fiberglass is a common material for sinks because it is relatively light and easy to clean. One drawback, however, is that it is a soft material that can get scratched. Once it scratches, dirt will settle in the cracks, which makes them more visible. This will show your sink's age and will make it look dirty and eventually become very difficult to clean. Restoring the fiberglass sink involves cleaning it and then applying fiberglass coating.
Add a few drops of liquid dish soap to a cup of warm water. Mix it until you see soap suds form.
Dip a sponge into the mixture and rub it over the fiberglass surface to remove as much of the dirt as possible.
Brush the cleaning solution into the cracks with a nylon brush. Do not apply too much pressure as you might widen the cracks.
Rinse the area with water and let it dry completely.
Mix the fiberglass repair filler with the cream hardener, according to the manufacturer's instructions.
Spread the filler paste over any nicks or deep scratches. You will be able to buff out all light scratches, but should fill the deeper scratches. Spread the filler with a plastic spreader to get a smooth surface.
Let it dry completely.
Sand the areas with 80-grit sandpaper to even out the surface. Repeat this process with 180-grit and then 360-grit sandpaper.
Wipe off the sawdust with a cloth soaked in clear water. Let it dry completely.
Mix the gelcoat, according to the manufacturer's instructions. This will normally consist of mixing the gelcoat with hardener and acetone.
Pour the gelcoat into the tank of a spray gun. Attach the tank to the spray gun and put on goggles and a dust mask.
Spray the entire sink with the gelcoat. Do not depress the trigger without moving the spray gun as this will apply too much paint to one area and will cause it to drip.
Let the gelcoat dry for several hours.
Soak a cloth in acetone and rub it over the entire sink. This will remove the tacky surface of the gelcoat.
Wet the entire sink and sand it with 360-grit wet sandpaper. Repeat this process with ultra-fine 1200-grit wet sandpaper.
Rinse off the sink and let it dry completely.