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Will Chem Film damage brass hardware

Can I install brass hardware into aluminum parts before chem film like we do with SST hardware or with the plating process damage the brass hardware?

Robert Knatz
Manufacturer - Chandler, Arizona
April 25, 2008

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First of two simultaneous responses --

Hex Chromates for brass and copper are the same as for aluminum except for data sheet, price, and label - will not hurt your brass.

Robert H Probert
Robert H Probert Technical Services

Garner, North Carolina

April 28, 2008

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Second of two simultaneous responses --

Brass inserts prior to chemical conversion coating aluminum has 2 problems: (1)if nitric acid baths are used to deoxidize the aluminum, they will attack the brass, and even if they're not, the chromate in the conversion bath is likely to attack the brass; and (2) putting copper into the chromate conversion coating bath will lower the ability of the resulting chemical film and subsequently processed parts to pass salt spray. Can they be put in - SURE - but bad practice for a couple of valid reasons.

Milt Stevenson, Jr.
Syracuse, New York
April 28, 2008