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-----Zn-Ni alloy stripping
In stripping of electroplated Zn-Ni deposit, we alway found black ash on surface and this ash can only be removed by rubbing. Is there any cleaning method can remove this black ash?
Thank you for helping.
Engineer - SHENZHEN, CHINA
February 14, 2008
You haven't told us about your situation, John, so that we can guess what the black ash is and how to prevent it or remove it chemically. How do you strip the parts, what are they made of, is the stripping electrolytic, what is the solution, is it done on racks, in plating barrels, or in bulk?
Ted Mooney, P.E.
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finishing.com - Pine Beach, New Jersey
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February , 2008
February 17, 2008
Originally we would like to strip off the bad quality Zn-Ni plated
(13-14% Ni) articles (Rack) by 50% HCl, but we found that the surface was covered by a layer of black ash even long time dipping in the acid. Soak cleaning and Electro-cleaning (anodic) seem no help to remove this black layer. The only way we found to remove this layer is by rubbing and so we would like to know if anyone can suggest us an alternative method to remove this layer easier.
Thank you.
- China
I have only a hunch, not facts, but I suspect that the plating is stripping off easily but in the course of doing it you are causing the substrate to get smutty by too heavy an acid treatment. Try reducing the concentration or immersion time.
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
Need quick confidential answers? $25
Need project assistance? $100/hr.
February 21, 2008
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