The Influence of Steel Coating Type and Galvanneal Coating Structure on Electrocoat Primer Paintability

The electrocoat operating windows of five automotive sheet steel products (uncoated cold rolled, electrogalvanized, hot dip galvanized, electrogalvanneal, and hot dip galvanneal) were compared. The effect of variations in base steel chemistry and galvanneal coating structure on the operating window were also evaluated. While all variations exhibited an acceptable electrocoat operating window, there was a measurable difference between the five sheet steel products. There was no effect of the galvanneal coating structure or base steel chemistry on the operating window.