Metal finishing Q&As since 1989

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Require Formulation of Non Chromate Passivation

Dear sir,

we are manufacturing of pretreatment chemicals like degreasing, derusting, phosphating, passivation.

We came to know that there is non-chromate passivation and hence request us to suggest in making non-chromate passivation which withstands 24 hours of saltspray test without oiling or painting.

Thanking u

regards Sreenivas

Sreenivas
- KARNATAK, India
2001

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By "non chromate" do you mean no hexavalent chromium or no chromium at all? Because a trivalent chromate process can withstand 24 hours.

Because of possible trade secret issues that it would be impractical for us to deal with considering the partial anonymity of the web, we can't put formulations here, but will be happy to include references to published data if anyone can provide it.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2001

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Dear Mr. Mooney,

To help out here, I think what Mr. Srinivas is looking for is a substitute for the final sealant after a zinc phosphating line. Anything instead of Hex Chrome.

Khozem Vahaanwala
Saify Ind

Bengaluru, Karnataka, India

2001

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There are some good non chromated sealers for zinc phosphate but they are trade secrets (as Ted already mentioned). Unfortunately you will have to ask your supplier for it.

Sara Michaeli
Tel-Aviv-Yafo, Israel
2001