By Tom Pawlak — GBI Technical Advisor
If the patterned non-skid on your production-built fiberglass boat needs repair, you may be interested to know that flexible molds are available for making professional-looking repairs.
If the damage to the deck is more than cosmetic, repair it prior to continuing. Refer to the procedures for structural repair as described in our Fiberglass Boat Repair & Maintenance manual.
Flexible molds are designed to lock into the existing molded pattern on your boat and work best if the pattern has not been painted over. If paint has been applied or if debris has accumulated in the pattern, the fit will be poor at best and the repair will be harder to blend in. Mold release is applied to the flexible mold at the factory so epoxy or the polyester gelcoat used to make the repair will not stick to it.
- Apply mold release wax to existing non-skid prior to beginning the actual repair. Spread wax well beyond the actual repair because gelcoat will migrate. Use wipe on/wipe off method to apply wax.
- Use a router to remove the damaged non-skid. Remove only the thickness of the pattern, no more. If you grind through the opaque white gelcoat or you can see the dark substrate through it, you must then fill the dark low spots with gelcoat so that after molding a new non-skid you do not see the dark laminate through the thinnest, lowest parts of the gelcoat pattern.
If the damage went beyond the base gelcoat thickness, or you are finishing a structural repair, you will have to router a void to fill with a thick enough layer of gelcoat to make an opaque base for the pattern. This layer of gelcoat is then machined with a shallower pass on the router, to level the opaque layer and establish the base of the non-skid pattern. Break the corner of the routed area with sandpaper.
- Position the flexible mold over the area to be repaired, moving it around until it locks onto the pattern. Tape one end down securely and roll back the flexible mold until the repair area is accessible.
- Pour catalyzed gelcoat (you can use epoxy but it will require painting) near the flexible mold.
- Slowly flex the mold forward while continuously engaging the non-skid pattern. Use a stiff rubber or plastic spreader to uniformly apply pressure to the backside of the flexible mold, effectively squeezing out the excess gelcoat. Allow the gelcoat to cure before removing the mold. Clean up excess gelcoat film (surrounding the repair) with an air nozzle or by brushing the area with a stiff bristled brush. When done correctly, the repair will not be detectable.