Gelcoat filler is a filled version of polyester gelcoat. Due to its Higher viscosity, gelcoat filler allows you to fill larger voids, gouges, scrapes etc on vertical surfaces without sagging.
REPAIRING DAMAGE TO GELCOAT
1) Ensure the damaged area is clean, dry and free of oil, wax or grease. It is sometimes useful to gouge out a scratch (preferably with a V shaped tool) to ensure maximum adhesion of the filler. Tape round the damaged area with Masking Tape to protect the surrounding surface..
2) Put the required quantity of Gelcoat Filler in a plastic mixing cup and add hardener as indicated in the table below and stir thoroughly.
MIXING GELCOAT FILLER
Gelcoat Filler Hardener
3) Fill the void proud of the surface. Use wooden spatula to press filler firmly into the scratch. Avoid getting filler on the surrounding surface. Remove the tape before the filler sets. Leave filler to cure thoroughly for at least 12 hours.
4) If necessary, rub down with Wet & Dry Paper, then buff with polishing Compound. It is a good idea to tape round the repair again, to avoid cutting into the undamaged gelcoat.
FILLING DENTS & CRACKS
holes, cracks and dents in most GRP, metal or wooden surfaces can be filled with Gelcoat filler. For smaller chips dings and scrapes we’d recommend just using gelcoat rather than this filler version due to its lower viscosity see our gelcoat repair section for our full range of coloured kits
You can also make a repair dough by mixing lay up resin and chopped glassfibre strands. This is used in the same way as body filler, but is much stronger and has better gap filling properties. It can be used on virtually any surface, including boat hulls.
Gelcoat filler is best finished off with flowcoat before polishing due to its tacky finish or mylar release film can be used to expel any exposure to air helping it cure without tack. Alternatively after 24 hours of full cure you can use a sharp blade and drag this over the surface to scrape off the tack finish prior to cutting back and polishing.