Q. We are a shop doing classic copper/nickel/chromium plating. Most of the parts we process are steel, but we also plate some zinc die casts. Over time, our nickel tanks get contaminated with zinc. What should we do to remove the zinc from our nickel tanks?—F.S.
A. The most immediate thing to do is to dummy your nickel tanks using a current density of 2-3 amps per square foot. This is a short-term solution, however, since it will disrupt production. A better way is to set up a continuous “side-stream” dummying process. In this way, your nickel baths will be more consistent.
Also, you should look at your whole process. Why are you getting large quantities of zinc in your nickel tanks? Are all the tanks raked for dropped parts on a regular basis? Is your copper plate consistent?