Moving Beyond the 25-Year Coating

From JPCL, December 2017

By Todd Williams and Ahren Olson, Covestro LLC, and Paul Vinik, Florida Department of Transportation

Zinc-rich primers have been well studied, yet specifying inorganic (IOZ) or organic zinc (OZ) for three-coat systems remains a highly debated topic. During the 1960s and 1970s inorganic zincs became the dominant primer in North America and published literature shows IOZ outperforming OZ in three-coat systems. The study presented in this article focuses on evaluating two variables within the traditional ZEU system that could impact performance — zinc-rich primer type (i.e., inorganic or organic) and topcoat chemistry....