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

-----

Acid Zinc Bath Contamination

Q. We have acid zinc plating barrels (chloride based). Since last 2 months we are facing issue of white contamination floating on the solution surface in the morning before starting the bath. Kindly refer the attached photo. Also along with this i see a lot of white substance floating inside the solution, which is also carried to next steps of nitric and Passivation.

61846-1a

61846-1b

I am not able to trace the source and cause; kindly help.
Our process is -
1.Degreasing
2. 2 nos of Water Rinse
3. Acid Pickling
4. Water rinse
5. Acid Activation
6. Barrel plating.

Aniket K
CEO - Maharashtra, India
May 16, 2025

A. Hi Aniket

My initial thought is that this is an extreme example of "oiling out" ⇦ huh?. While awaiting further input here and from your plating process supplier, please see the "Brown sticky slime on surface of chloride zinc plating tank" subheading of thread 400/95.

Luck & Regards,

Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
Ted is available for instant help
or longer-term assistance.

(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: