Metallic Coatings for Structural Steel in Marine Environments

This article discusses a comparative evaluation of the performance of various types of protective coatings available for the corrosion protection of structural steel components located in marine environments. An inorganic zinc primer, thermally applied zinc (99%), aluminum (99.5%), 85/15 zinc-aluminum alloy, and a new dual-coat system comprised of one coat of thermally applied zinc with a topcoat of thermally applied aluminum were evaluated. Some of the thermally applied systems were evaluated with and without a sealcoat. Also evaluated were hot-dipped galvanized specimens with and without the top-coat sealer, and specimens treated with a thermal diffusion galvanizing process.