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Trivalent clear chromium

We are an Importer; being asked by an automotive company if we can source in China a simple front plate which is for Daimler Chrysler.

The part is of a base material spec; low carbon steel

The finish requested is zinc electroplate with iridescent clear trivalent chromium.

We have found mfg. sources in China who can make the part, but have not been able to find anyone who understands the specification for trivalent chromium. They understand the Hexavalent Chromium.

I would like to furnish the plater with a proper spec which will give them the chemical awareness of trivalents. Can you help point us to the proper source for a plating standard which establishes the chemical ingredients and the plating process/equipment; etc. ?

Respectfully,

Bob Schieck
- Antioch, Illinois, USA
2002

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Your question should be labelled as hazardous material, Bob. I'm sure it caused at least a hundred U.S. platers a bleeding tongue :-)

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2002

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You're probably running into confusion because there are 2 specifications that you need. One is for the plating, and one is for the trivalent chromate. The DCX spec for zinc plate is PS-PLATING, and the DCX spec for the trivalent chromate is PS-1207.

Tim Neveau
Rochester Hills, Michigan
2003

It is so important that we are able to name a customer's specification. DCX's is PS 1207. I believe (one of)Ford's is WSS-M21P17 B1-B5 for trivalent clear coating over zinc. Enter the spec # into your search engine; you'll probably find platers and coaters who claim they do meet that spec. They are most helpful in explaining the process!

Mary Schuman
- Lake Zurich, Illinois, USA
2003