Copper Shield Hard Epoxy provides full season antifouling protection for boat bottoms against barnacles, algae, and hydroids in salt and freshwater. Its modified epoxy base renders a smooth finish with durability and abrasion resistance. Copper Shield Hard releases biocide during the exposure of paint film to the water. Copper Shield Hard has universal application over all types of properly prepared bottom paints (except aluminum). For use on fast fiberglass boats as well as wood and steel hulls.