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
-----

Alternate for Dichromate Sealing

2003

Dear Sir,

We do anodizing of sulfuric type. After anodizing, we do hot potassium Dichromate sealing to get yellow in color. Since we propose to eliminate the use of hexavalent chromium in the process, we seek alternate chemicals / process to get yellow color after anodizing.

Please suggest me, if any.

D. DHANASEKAR
- HOSUR, Tamil Nadu, India

I don't see why you could not dye them yellowish-gold before hot water sealing if you wanted. There are, I believe, also two-step processes and oxalic acid processes that would give you a yellowish-gold color.

But this idea of everyone insisting that their chrome-free parts must look toxic and carcinogenic is starting to drive me loony :-)

If you are bearing extra costs, plus suffering diminished corrosion resistance and other problems to make your coatings eco-friendly, talk somebody into allowing them to be green instead of toxin-colored for goodness sake!

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
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: