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Black Ebonol fades to brown in storage

May 31, 2011

Our company had some copper parts that were coated with Black Ebonol and were stored in a plastic bag in the stockroom for several months. When we went to use them they are no longer black but brownish and areas of the parts are no longer plated. Another lot which has been in stock for only two months look fine. Is this a known issue with Black Ebonol coatings or possibly a problem that relates back to the coater?
Thank you for the help,
Bob

Bob Trottier
Quality Tech - Londonderry, New Hampshire, USA

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Same base material? I'd offer a couple of suggestions: (1) rinsing, Ebonol C bath is highly caustic and not readily rinsed free and (2) copper alloys like brass require better activation and can appear less black. Typically activators are used to de-zinc the brass prior to blackening. Our firm does Ebonol C regularly and I really have never had a customer commenting about black parts which fade to brown over time. Hope this helps.

Milt Stevenson, Jr.
Syracuse, New York
June 3, 2011