Hazy Decorative Chrome
Why do some of our larger parts appear to have a hazy finish when our smaller racked parts do not?
Q. When I plate larger parts, such as restoring auto bumpers, the parts appear to have a hazy finish, particularly in the central portions of the part. I do not have this problem when I plate smaller racked parts. What is going on? –J.B.
A. What you are observing is often called "whitewash." This can be caused by a number of different things. Since you mentioned that the problem seems to appear only with larger parts, I think the cause is change in the current density and temperature of the plating bath when the part is placed in the bath.
It is important that the part should be at or near the temperature of the plating bath. The current density should be adjusted to compensate for the larger surface area of the part. You should also investigate how electrical contact is made with the part. For example, in a part like a bumper, you may require more than a single electrical contact.
There are a number of good articles on whitewash on PFOnline. Use the search term, “whitewash.”
Our expert, Art Kushner, says yes, you can color stainless steel, but it is not a process that is typically performed in a plating shop. Read more about his answer.
Masking is employed in most any metal finishing operation where only a specifically defined area of the surface of a part must be exposed to a process. Conversely, masking may be employed on a surface where treatment is either not required or must be avoided. This article covers the many aspects of masking for metal finishing, including applications, methods and the various types of masking employed.
Choosing the best process for your operation.