52084

Black Spot Problem  

April 27, 2009

Hello, I have a problem about electroplating: I have plated the axle wheel at my supplier but there are black spots on the surface of product especially on the shank area.
I have checked electroplating parameter and there is no problem with them but i am suspicious with rinsing water condition.
Test result shows : degreasing water rinse => TDS:521~617 ppm, pickling water rinse=>548~4710 ppm, electroplating water rinse 540~2270 ppm & chromating water rinse 513~516 ppm.
Based on the water rinse data, do you think our rinsing quality is proper enough ? is there standard quality for water rinse of electroplating.

Regards Yudi W.

Yudi Wahyudi
Engineer - Jakarta Utara, Jakarta, Indonesia

Hi, Yudi. You have not told us anything about your plating process to enable anyone to advance the alternate theory that it is a plating problem. Low quality rinse water can cause many problems, but "black spots" doesn't sound like a likely one to me. I suspect the black spots are iron contamination of the zinc plating bath. Please tell us about your plating process.

Regards,

Ted Mooney, P.E.  finishing.com Brick, New Jersey