Q: We are having problems with pitting in our nickel sulfamate plating bath. What should we do to solve this problem? J.M.
A: It's time to review a few simple things that can cause this type of problem. I have addressed this issue in a past column and here is what I wrote at that time.
Your pre-plating cycle can be at fault. If the parts are not thoroughly cleaned and grease or oil is left on the surface, pitting can occur. Contamination of the plating bath can cause pitting. This can be due to organic contamination or particulate matter in the plating bath. Surface defects of the part itself can also cause pitting.
"What can be done about these causes of pitting? The answers should be fairly obvious to any knowledgeable plater! Check out your pre-plating cleaning steps. Do your parts pass the "water break test?" How clean is your nickel plating bath? Is the bath being filtered on a continuous basis? Is the filtering system working properly? Are organic contaminants being removed on a regular basis? Is the plating bath being carbon filtered on a regular basis? If an anti-pitting agent is used, is it added on a regular basis and is it replenishing after carbon filtration?"