Zirconization of Anodized Aluminum: Smart Paint Adhesion Advice

Summary for zirconization of anodized aluminum Discussion

Zirconization of anodized aluminum is questioned here in the context of a sulfuric-acid anodized, nickel-acetate-sealed aluminum bowl that will later be painted. Timothy Barr asks whether the zirconization step will make the surface suitable for paint adhesion. The reply says the ideal pretreatment for aluminum that will be painted or powder coated is chromate conversion coating or trivalent chromate conversion coating per Mil-C-5541. It also warns that anodizing, especially sealed anodizing, is generally a poor surface for paint or powder coat adhesion. The answerer says zirconization of anodized and sealed aluminum is a special case and should not be guessed at; for existing parts, Timothy should ask DuBois or the distributor what they have learned about that specific process. For new parts, the advice is to skip anodizing and instead chromate-conversion-coat the raw aluminum for better results and lower cost.