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Can't repeat a nice black EN coating on silver

2003

Dear gentlemen,

I wanted to plate my silver items with nickel. So I cleaned and immersed them into the electroless nickel bath with zinc contact. Then after five minutes the items came out as shiny black in colour. In fact I liked it. I tried to repeat the process but unfortunately I got bluish in colour instead of black. My question is in each time when I use the fresh bath I get shiny black in colour. Why I can't repeat it. I think the solution is losing some chemicals. What are the possible explanations getting black and then blue?

With my best regards,

Murat Gure
Laser Diode process Engineer - Ankara, TURKEY

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It would be much easier for someone to conjecture what happened if we had more facts, Murat. You have told us little about the EN bath type or composition yet.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2003