New England Transportation Consortium Research Study 05-5: Measurement of Adhesion Properties between Topcoat Paint and Metalized/Galvanized Steel with Surface Energy Measurement Equipment

For many highway transportation products, a zinc coating is added to the structural steel to act as a sacrificial layer for corrosion protection. Zinc is applied to steel in three ways – by a zinc-primer paint, by metallizing (where hot zinc is sprayed onto the steel surface), or by galvanizing (where the steel part is immersed in a molten zinc bath and a zinc layer metallurgically forms on the steel). Paint topcoats are often applied to zinc-coated steel surfaces to provide additional protection and an aesthetic color finish. The adhesion performance of these topcoats appear to vary considerably for coatings applied over galvanizing versus metallizing. The effectiveness of different zinc coatings with topcoat paint applications can be quantified by measuring adhesion properties between the topcoat paint and zinc-coated steel. Measurement of these adhesion properties is the primary objective of this research.