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
-----

Thick black foam in passivation tank ?

My name is Mike Nelson I am the Special Processes Manager of Machine Shop. I have a passivation line set up to ASTM A967 nitric 1. This afternoon I found a thick black foam floating on top of my passivation tank. The tank tested good 24% nitric acid 2.5% sodium dichromate. Has anyone seen this before? If so can you tell me what it is or what caused it? Thank you for any help you can provide

Mike Nelson
Special Processes Manager - Chattanooga Tennessee
January 14, 2011

(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: