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

-----

Hexavalent versus Trivalent Chromate as a zinc passivation

2007

Is it true that Hexavalent Chromate is considered resilient and repairs itself when used as a conversion coating or post treatment with electroplated Zinc?

And is the opposite true with Trivalent Chromate when used in the same manner that it is not resilient and does not repair itself?

Repair in terms of self healing of slight surface scratches, so that corrosion resistance is restored.

Raymond Lafferty
- Elmhurst, Illinois, USA

I believe that that is still true, Raymond. A complicating factor, however, is that all trivalent replacement chemistry is very highly proprietary and several radically different approaches have been taken: thin film vs. thick film, topcoat vs. no top coat, etc. It is very hard to say anything hard and fast about trivalent chromates except that they comply with hex-free requirements.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2007

(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: