Coatings Manufacturer’s Use of Accelerated and Field Tests to Evaluate Coatings

Abstract The correlation between accelerated weathering (Weather-Ometer, QUV-A, QUV-B, salt fog/QUV-cycle, Envirotest), and accelerated corrosion testing (salt fog, water fog) vs. outside Midwest exposure is discussed for various generic types of coatings, including VOC compliant products. Poor correlation between performance in salt fog exposure and outside weathering was demonstrated. Various mechanisms of failure are described. Good correlation was found between polarization resistance, measured with AC Impedance technique, and outside weathering. The coating manufacturer’s approach in evaluation of coating performance based on "testing package design" is discussed.