How to Repair Fiberglass Deck

Fiberglass Deck Job

Scuff up plywood with sander. When Plywood is NOT wet or hot – pour Resin with hardener (MEKP) onto plywood and immediately spread it onto the plywood. It is best to do this in the evening and to use only a ½% MEKP. This will slow down the Resin cure, allowing the Resin to penetrate deeper into the plywood.

Once Resin has kicked (hardened) – knock out the shine with a sander. Precut glass (all layers). Butt up the layers – do not overlap, because you will need to sand off the over-lapped bumps. If only using one layer, fan out the glass with a piece of sandpaper. This will leave a hairy edge and eliminate the bump. Spread a small amount of Resin onto the plywood before applying the glass. This will saturate the mat more evenly.

Place glass on the plywood. Use throw-away brushes or rollers to apply the resin. A “bubble buster” roller will help eliminate air bubbles and will also spread the Resin more evenly. ** Boats with a closed bilge It is recommended to glass the bottom of the plywood with ¾ ounce Mat (chopped Mat). Resin by itself will sometimes crack and allow moisture into the wood which could cause rot. The glass on the bottom of the plywood will also stiffen the deck and make it more rigid.


Two layers of Gelcoat are recommended. First Coat: Use Gelcoat with NO Wax, this will stay sticky and will eliminate the need to sand between layers. Last Coat: Use Gelcoat with Wax. The wax floats to the surface and blocks out the air, allowing the Gelcoat to harden without stickiness. ** Continuously stir the Gelcoat because the wax will float to the top even in the bucket. After the Gelcoat cures, if it is sticky in patches, it is probably because the Gelcoat in that area did not have wax in it (due to not stirring). This can be remedied by spraying PVA on the sticky area. TIPS: You will have more working time if the Gelcoat is poured onto the surface and then spread out. Two Roller Method Use the first roller to evenly spread the Gelcoat on the surface. Use a second dry roller to eliminate the roller lines and give an even texture. Non-Skid Make a sieve out of a bucket (poke holes in the bottom of bucket) and shake grit evenly on wet Gelcoat. When Gelcoat dries blow off loose grit. Apply last coat the same as first coat, but with waxed Gelcoat.


Apply webbing before last coat of Gelcoat dries.

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