What causes roughness on the tops of nickel-plated parts?
Q. We have a nickel plating line that has started to give us fits. We experience roughness that is usually present on the top surfaces of the parts. We also have a problem with some of our parts coming out hazy on one side and just fine on the other side. What do you suggest to solve these two problems? —M.K.
A. Particulate matter in the plating bath is usually the cause of roughness on the top surfaces. Are you filtering the plating bath on a continuous basis? You should use a 5- to 10-micron filter and change it out on a regular basis. Your anodes should be bagged. If your plating bath is not used on a daily basis, it should be covered when not in use. You'd be surprised what can fall into your plating tank when it is left uncovered.
The hazy appearance on one side of your parts may be due to poor current distribution, so you should look at your anode distribution. You should have enough anodes present in your plating tank to ensure good current distribution. I always like to say that you're parts should "see the anodes." If the line of sight is seriously blocked, you will not get consistent plating over the surface of the part.