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Film Build-up After Anodizing

We are a sulfuric acid anodizing facility, anodizing small parts. We have had an ongoing problem with film build-up during a customer's automated vibratory bowl feeding. This wipeable film builds up on the feeder bowl as well as the parts. We are not sure of the source of the film, nor how to prevent its occurrence. We use a nickel pre-seal and a hot boiling water seal and preliminary tests seem to show we are adequately sealing these parts. Is this realy a sealing problem or a break-down of the anodic film? Is there anything we can do to prevent this from occurring?

Margaret E. Wessman
Anomatic Corporation, Newark, Ohio
1998

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This is simply a wild guess, Ms. Wessman, but I think it may be coming from the bowl, not the parts. Remember that an anodized coating is aluminum oxide. So is sandpaper.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
1998