2019 CSCE Annual Conference - Laval (Greater Montreal) Conference
Mr. Martin Gagné, International Zinc Association
Dr. Frank Goodwin
Large Steel structures are almost always – resulting in situations like the Golden Gate Bridge, San Francisco, where they have a near constant re-painting program.
There are better ways to spend tax-payer money and utilize the skills of our workforce.
Enter Duplex coating systems. Metallic zinc coatings with a paint top-coat, or ‘Duplex Coatings’, offer both barrier and sacrificial corrosion protection mechanisms providing more than twice the corrosion protection provided by one coating system alone. Empirical evidence shows that, duplex zinc coatings can provide 1.5 to 2.3 times the sum of the expected life of each system alone.
A paint top-coat over a metallic zinc base layer protects the zinc from initial corrosion. The zinc base layer similarly protects the paint from under film corrosion at scratches and holes. The synergy between the two coatings provides protection far superior to either system used independently. This system also seems improved impact and abrasion resistance, resulting in longer lifetimes between maintenance compared to paint only coatings.
Duplex zinc coating systems have decades of proven performance protecting steel infrastructure from corrosion.