The Waterborne Symposium

Abstract
The Navy updates military detail and performance specifications to incorporate advances in coating technology as well as to provide Fleet customers with coatings that offer enhanced performance. The Naval Surface Warfare Center, Carderock Division (NSWC-CD) is modernizing naval capabilities through the revision of TT-P-28, the NAVSEA specification for liquid and powder heat resistant coatings and MIL-PRF-24712, the NAVSEA specification for general purpose thermosetting powder coatings. Developments in coating technology have resulted in liquid and powder coatings with enhanced color retention, corrosion resistance, and heat resistance. For example, laboratory testing has shown that some commercial available topside coatings offer surprising levels of heat stability analogous to the performance of TT-P-28H, Type I coatings at specific temperature ranges and in certain applications. In addition, these coatings are cleanable and color stable, making them ideal for exterior application. However, because TT-P-28 is a formula based, detail specification, new requirements were needed for the Navy to adopt these high performance coatings. Publication of the TT-P-28J in July 2021 included new types and classes of coating to include these new liquid and powder coatings as well as including new requirements for heat resistant coatings to serve as thermal spray nonskid topcoats. In addition, NSWC-CD is revising the MIL-PRF-24712 thermosetting powder coating specification to include new types and classes of environmentally acceptable coatings. Currently, the triglycidyl isocyanurate (TGIC) powder coatings qualified to MIL-PRF-24712 for topside service are considered hazardous in Europe and Australia and regulatory constraints on use of such coatings in the United States could adversely affect the ability of the Navy to powder coat parts. As such, NSWC-CD will develop requirements for new, more environmentally acceptable powder coatings. The paper will describe the changes to the specifications, including new material allowances, test methods, and classifications and show how some of these new coatings performed during ship demonstrations and laboratory testing.