Due to the higher initial cost of metallized coatings, long term, maintenance free performance is necessary for consideration of metallizing as a corrosion control option for bridges. When applied properly, these coatings have shown excellent long term performance when compared to more conventional paint systems, especially in more severe coastal and salt-rich environments. Sealing is recommended by most existing guidelines as it tends to increase coating lifetime, reduce the deleterious effects of metallized coating porosity, and improve aesthetics. Sealers of various generic types exist and are compatible with a metallized substrate. It is important to use a sealer of sufficiently low viscosity to penetrate and fill any porosity in the metallized coating.
Metallized coatings provide the benefit of defect tolerance.
The sacrificial nature of these coatings provides protection to the surrounding steel at the site of unintensional breeches in the coating film. In addition, the adhesion of metallized coatings is sensitive to contamination. Conventional peening with rounded shot has produced poor adhesion. Consistent and Uniform Application - metallizing is a solventless coating application method and as such is somewhat less forgiving than conventional paint application. Applicators should be properly trained and experienced with the specific equipment and metals or alloys to be used.