Letter 11050

How to decrease the Pb concentration of non-plated internal surface of bright chrome plated brass parts 

We want to decrease the Pb concentration of non-plated internal surface of bright chrome plated brass parts. Do you have any idea about such a process? Is there any plating process that covers the internal non-plated surface without giving any damage to the bright chrome plated surface?

Ozkan Bekiroglu
- Bozuyuk, Bilecik, TURKEY

Where did the Pb come from? How was it deposited? Brass does not contain Pb.

Bill Hemp
tech svc. w/ chemical supplier - Grand Rapids, Michigan

You could immersion Sn plate the brass part after plating is one way to limit the leachable Pb from the surface.

George Shahin Atotech USA Inc. Rock Hill, SC

Most brass alloys for the plumbing industry have some Pb in them - for machinability. There are proprietary acid blends available that will leach out the lead and leave a surface that will pass the NSF lead exposure test. My company has been actively involved in this aspect of plating for several years now. There are also ways of lead leaching that are post-plate, but we have found that a pre-plate application keeps from damaging the final finish.

Dan Brewer
plating process supplier - Gurnee, IL

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