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. Mixes translucent light brown when liquid hardener drops and resin are mixed thoroughly and ready to use. Bondo clear liquid hardener included.