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Light blue clouds on electroless Ni-surface

2006

Hello,
we see (at 20x magnification) on our electroless Ni-surface (high-P on steel or sulphamate_ni/steel) sometimes light blue 'clouds' or stains on the surface. The parts were rinsed three times after the Ni-bath (last rinse < 5µS) and then dried in centrifugal dryer with hot air (60-80 °C).
Can anyone explain these 'clouds' and how can I avoid these clouds, or clean this surface?

Franz Schubert

Your first rinse has to be slightly alkaline (around pH 8) to neutralize the adhered film of plating solution over your parts' surface. NaOH or ammonia ⇦this on eBay or Amazon [affil links] in small amount work for us.

Guillermo Marrufo

2006