Nickel Balls

 Q. We have a problem with our EN (high-P): after two to three turnovers, we have nickel balls (about 50-100 microns) forming on our parts; after one to two more turnovers it’s OK again. The bath is filtered by a 10-micron filter (6-8 times/hour). Stability and the other parameters are also OK. Can you explain this effect? N.O.

A. I must admit I have not run across this in my years in the plating industry. My only suggestions would be as follows:

1. Better filtration (1- to 5-micron filter and 10 turnovers per hour).
2. Cover the bath when not in use (prevents dust and grit from getting into the bath).

My thinking is that somehow particulate matter gets into your tank and causes small nickel balls to form on the surface. In order to pin this down, I would docu-ment in detail such things as time of day, repeatability of this phenomenon, etc. Also if any of our readers have insight as to what is going on here I would love to hear from you. E-mail me at platingclinic@pfonline.con.