Cause of white spots on dyed 2024 aluminum 

Letter 10060

I'm having trouble with white spots when anodizing and dying 2024 T3 aluminum. Usually the parts are machined all over and seem to have little pin holes where the spots are. What am I doing wrong? Am I zapping the parts with too much electricity? My current solution is at 19% and I am anodizing at 16 volts. I have a 1000 amp rectifier.

Please forward any solutions.

Bill Smith
anodizing shop - Trinity, North Carolina

How many minutes do you anodize and at what temperature?

Dado Macapagal
anodizing shop - Toronto, Ontario

Hi, Bill. You might want to consult Robert Probert's "Where Do White Spots Come From" in our on-line library. Good luck

Regards,

Ted Mooney, P.E.  finishing.com Brick, New Jersey