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Best post-treat for galvanneal

I am not all that familiar with coatings hence my question. I have been asked to quote a galvanneal panel with a chromate conversion coating. I have been told that an iron phosphate coating would be better suited for this application. Is this correct and why? This panel may not necessarily get painted afterwards.

Michael Constantino
Product Engineer - Grand Rapids, Michigan, United States
2003

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Hi Michael,

Choosing between using iron phosphate or chromate on galvanneal will depend on the application. Because you have said that the panel may not be painted, I would go with the chromate treatment. Iron phosphating is a pre-paint treatment and generally will not provide very good bare corrosion protection. A chromated galvanneal surface will have much better bare corrosion protection.

George Gorecki
- Naperville, Illinois
2003