Penetrating resins are frequently used to repair rotted and decayed wood; they sink into the wood fibres and harden, restoring structural strength to the wood and making it waterproof. There are also several reasons to use these resins in boat construction. They will make the wood water-repellent, resisting any future moisture incursion. They also allow for the use of highly flexible plywood in shaping the boat; once the plywood is bent into place, the epoxy is applied and stiffens the wood into shape.
West Marine Penetrating Epoxy
West Marine Penetrating Epoxy is a two-part product that is mixed in a 2-to-1 ratio by volume. Once applied, it sets within 60 minutes and fully cures overnight. It cures to a clear amber colour, and may be sanded and painted after it cures. West Marine offers it in 113 and 454gr quantities, but boat builders may be more interested in the 907gr kit.
Git Rot Penetrating Epoxy
Git Rot is specifically designed for repair of rotted wood cores in fibreglass boats, so it seems ideal for protecting those cores before the fibreglass is laid on. It has a relatively short, 30-minute working time, dries overnight and achieves full strength in about a week. This two-part resin dries to a clear amber colour; the manufacturer recommends applying a volume equal to half the volume of the treated wood in order to fully saturate it. It is available in 4, 16 and 32-ounce kits.
Rot Doctor Clear Penetrating Epoxy Sealer
Like other penetrating epoxies, Rot Doctor Clear Penetrating Epoxy Sealer is a two-part epoxy formula that soaks into wood thanks to a powerful solvent mixture. Rot Doctor claims that this sealer has a deeper penetrating power than any comparable product on the market: 16 inches of penetration into balsa from a 6ml application. The product is available in 2-pint, 2-quart and 2-gallon containers.
Epoxy-Plus Marine Epoxy
Epoxy-Plus is a two-part penetrating marine epoxy that is specifically positioned for boat building as opposed to boat repair. It cures to an ultra-clear finish, making it ideal for wooden boats which will not be covered by fibreglass, such as cedar-strip boats. The product is available in sizes from 1 quart all the way up to 10 gallons, so it is very suitable for larger construction projects. It has a working time of 30 minutes, with a set-up time of 8 hours.