Bondo Fiberglass Resin is an industry standard for restoration and repair of vehicles and boats. The high strength polyester resin features a waterproof formula, is highly durable and provides long-lasting repairs.Bondo Liquid Resin for Fiberglass is a high-strength polyester resin that can be used with fiberglass mats or cloths on surfaces including fiberglass, metal, wood, and masonry. This all-purpose material is used to repair breaks, and recreate or join surfaces. It can also be used by itself as a wood or concrete sealer. The 100% waterproof, two-part resin includes clear liquid hardener and can be used to repair cars, trucks, pools, showers, boats and more.