Demonstration of Thermally Sprayed Metal and Polymer Coatings for Steel Structures at Fort Bragg, NC

The Department of Defense spends billions annually on corrosion-related maintenance. It has recently been estimated that at least 25 U.S. Army installations have severe corrosion problems with above-ground steel storage tanks. Coatings are widely recognized as a first line of defense for protecting these steel structures. Thus, the Office of the Secretary of Defense Corrosion Prevention and Control Program sponsored a project that demonstrated and evaluated new technology with two thermally sprayed coating systems for corrosion protection of steel structures in severely corrosive environments. The technologies included metallizing a steel tank with zinc-aluminum alloy and flame-spraying a polyolefin powder coating on the legs of an elevated steel storage tank. This report documents the materials and application of the two coating systems and subsequent performance evaluations. Metallizing is more costly than traditional organic coatings and is often overlooked as an option. However, life-cycle costs in highly corrosive environments can actually be lower than using organic coating systems. As this project demonstrated, the flame-sprayed polyolefin coating is too costly for use on large steel structures. Guidance documents are identified to help make decisions on the use and procurement of metallizing coating systems. The projects return on investment was calculated to be 2.94.