HOME FAQs BOOKS JOBS: Help Wanted Suggestions you are here: Hotline/Forum => Letter 10060

Cause of white spots on dyed 2024 aluminum

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

February 19, 2009

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

ANSWER or FOLLOW UP POST an unrelated QUESTION HOT Topics

Disclaimer: It is not possible to diagnose a finishing problem or the hazards of an operation via these pages. All information
presented is for general reference and does not represent a professional opinion nor the policy of an author's employer. The
internet is largely anonymous; some names may be fictitious and some recommendations may be deliberately harmful.

If you are seeking a product or service related to metal finishing, please check these Directories: