Demonstration of a standard steel coating system modified with a vapor-phase corrosion inhibitor : final report on Project F12-AR14

Abstract

This project demonstrated the capabilities of a vapor-phase corrosion inhibitor (VCI) as an additive into an epoxy primer coating for exterior hangar doors in a severely corrosive environment. Typically, protective coatings used on steel structures use zinc-loaded primers to provide corrosion protection to the substrate. As a more environmentally friendly option, a VCI-modified coating system has been used instead of a zinc-containing primer. The VCI migrates to the steel substrate to form a microscopically thin, corrosion-inhibiting film. The demonstrated coating system was also applied to test panels exposed to atmospheric weathering and to laboratory salt-fog exposure testing. The VCI-modified coatings were applied to abrasive-blasted substrates and to surfaces without the rust fully removed. Although the VCI-modified coating system showed promise in the test panel exposure results-especially panels with a lower grade of surface preparation-it was unable to protect the steel doors due to high levels of mechanical damage they incur during normal site operations. Based on the test panel results, further evaluation of the VCImodified coating system is considered necessary before making a positive recommendation for Army and DoD implementation. Due to the results of this demonstration, the project return on investment was zero.