No passwords, No popups, No cost, No AI:
we earn from 'affiliate link' purchases, making the site possible

Sound technical content, curated with aloha by
Ted Mooney, P.E. RET
Pine Beach, NJ

finishing.com -- The Home Page of the Finishing Industry

  The authoritative public forum
  for Metal Finishing since 1989

-----

Black Spots in Chromic Acid Anodizing

Have problem with minute black spots showing up on chromic acid anodized parts sealed in dilute chromate seal. All tanks are in specification. The spots are only on certain areas of the parts, not on the whole part. When the chromic acid anodize is stripped, the black spots are visible and can not be removed chemically. Looks like a metal condition. Does anyone have any ideas?

Ray Handwerker
- Bensalem, Pennsylvania, USA
2003

What is the alloy? Please tell us the surface preparation. Voltage Ramp?

Robert H Probert
Robert H Probert Technical Services

Garner, North Carolina

2003

(No "dead threads" here! If this page isn't currently on the Hotline your Q, A, or Comment will restore it)

Q, A, or Comment on THIS thread -or- Start a NEW Thread

Disclaimer: It's not possible to fully 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 & unvetted; some names may be fictitious and some recommendations might be harmful.

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