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Reworking rejected Nickel-Chrome plated jobs on mild steel tubes

August 20, 2008

We are in the Nickel-Chrome plating business for the last year. Despite every effort to minimise rejections we have a pile full of rejected components. we have tried salvaging by
1.dechroming ,giving a dip in nickel activator on current and chrome.
2.dechrome, buff the nickel plated surface,use of emery 220/400/600 on certain areas, clean in alkaline bath, pickle in 60% sulfuric acid ,nickel plate and then chrome.
3.stripping of nickel n chrome was avoided as all brazing joints were dissolved and rebrazing was difficult and porous.

our problem is the success rate is hardly 10-15%. can you help out with a more better process.

Prasanna Borkar
plating shop owner - PONDA-GOA, India

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August 20, 2008

Hi, Prasanna. Number 1 is the correct approach. However, you must:

a). Locate the rejects quickly, before the nickel has a chance to really passivate with age.
b). Do a very careful nickel activation and re-nickeling (the parts will have two full layers of nickel).
c). Serialize the parts so that you are not endlessly recycling defective parts. In the bumper industry for example it is conventional to allow one attempt at replating.

Regards,

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