Advanced Nontoxic Fouling Release Coatings

Historically, marine antifouling paints have used compounds toxic to marine organisms as a means of combating fouling. Foul-release coatings don't use copper or any other metal toxicant to provide effective biofouling control; rather their unique surface chemistry creates a surface to which fouling can not easily adhere. Because they employ a physical rather than a chemical means to reduce fouling, these silicone coatings have been ruled exempt from reporting under FIFRA (Public Law 95-396). NRL developed and patented an advanced foul-release coating system called the duplex silicone coating system to address the durability issues associated with silicone elastomeric coatings. This system employs a tough, cross-linked thermoplastic elastomeric layer (Silgan J501, Wacker Chemie, Ltd.) to bond the foul-release silicone topcoat to the anticorrosive system for ship hulls or to epoxy paint on concrete walls in power plants. The ESTCP demonstrations/validations included 6 Coast Guard aluminum hull boats, 2 Navy Range Boats, a Navy Transporter, an ONR/Lockheed prototype (SLICE) and power plant cooling water intakes (concrete walls, steel trash racks/traveling screens/deflecting veins). Barnacle adhesion measurements (ASTM D 5618-94). Barnacle adhesion measurements and water jet cleaning were developed as part of this project. --Original contains color plates: All DTIC reproductions will be in black and white. Prepared in collaboration with G. E. Corp., Schenectady, NY, Florida Inst. of Tech., Melbourne, FL, State Univ. of NY, Buffalo, NY and Bridger Scientific, Inc., Sandwich, MA.