Shadow Plating
On some of our parts, we see what appears to be a “shadow.” What causes this and how can we prevent this from happening?
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
you.
Related Content
-
How to Choose the Right Coating for Fasteners
Choosing the proper coating for fasteners can help with performance by improving durability and lifespan. In this helpful Ask the Expert article, Mark Schario of Columbia Chemical offers advice for choosing the right fastener coatings.
-
How to Choose Between Sulfate and Chloride-Based Trivalent Chromium
There are several factors to consider when choosing between sulfate and chloride-based baths for trivalent chromium plating. Mark Schario of Columbia Chemical discusses the differences and what platers should keep in mind when evaluating options.
-
Trivalent Chrome Overview
As the finishing industry begins to move away from the use of hexavalent chromium to trivalent chromium, what factors should finishers consider as they make new investments? Mark Schario, chief technology officer for Columbia Chemical offers a helpful overview of this complicated topic.
