Q. Our company plates a large variety of different parts. On some of our parts, we see what appears to be a “shadow.” What causes this and how can we prevent this from happening? B.J.
A. You have a problem with current distribution. Current distribution in some ways is similar to sunlight. As you are well aware of when you stand in the sun a shadow is cast. In the same way when you are plating parts in a plating tank one part may be cast a “shadow” on another part.
There are a few things that you can try to solve this problem. The anodes can be rearranged to give you “better coverage” of the part. You can use conforming anodes to do the same thing. Shields made of plastic can be placed around the high current density areas of the parts being plated. Shadowing tends to be a problem in such processes as decorative gold plating and electropolishing. You will have to experiment with these potential solutions to determine which one will work best for