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Alodine Coating

2006

One of my customers is returning parts to us to trim the ends. The parts have been cadmium plated already and they state that "After trim, vendor needs to Alodine exposed ends".

In my research on Alodine it appears that it is not just something that can be painted on the ends and that it is for Aluminum. These parts are made out of music wire.

Is there a pen or paint brush method that can be used to Alodine the cut ends? And can Alodine be used on music wire?

Thank you,

Terry Austin
spring manufacturer - Stanton, California

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Alodine is a Henkel trade name for chromate conversion coating processes. Although Henkel certainly has chromate conversion coating processes for aluminum that go by the Alodine trade name, they have chromate conversion coating processes to be applied to Cadmium plating that go by the Alodine trade name as well. But in any case you cannot chromate conversion coat bare steel.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2006

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I have been researching Alodine and wonder if trisodium phosphate ⇦ this on eBay or Amazon [affil links] (TSP) can be used prior to using Alodine with the same results as other methods?

Bob

Bob McKellar
- Entiat, Washington
May 14, 2009

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May 18, 2009

Hi, Bob. I wouldn't do that. It may be possible to get the cadmium plated surface active by scrubbing it with TSP and a tampico brush (especially if it's more of a paste so it has some polishing action), but I think you don't want to scrub cadmium because it's a bioaccumulative poison.

Regards,

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