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Zinc plating thickness and appearance problems

February 16, 2008

Sir,

Recently we are facing a problem of plating thickness variation, some of the components are plated well but few are'nt. meanwhile appearance was found dark(black), addition of brighteners too did not give the satisfactory results, ensured bath is in healthy condition. Pl help me in resolving this issue

Plating: Zinc plating
Components: High tensile Fasteners.
Plating thickness desired: 6-8µ & 8-12µ.


Thanks & regards,

Kesav Reddy
process designer - Hyderabad, India

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Kesav,
Because the low thickness and appearance problems are present on only some of the parts, it usually means a poor connection on the plating rack. Parts with low thickness only, could just mean they are in the LCD area on the rack and additional plating time is needed. You could number the racks, record the rack number / parts. The racks that produce parts with low thickness and poor appearance should be tested for continuity, one prong or hook at a time. Make sure rack prongs or contacts are all tight on the parts before plating.

Mark Baker
Process Engineer - Syracuse, New York
February 22, 2008

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Hello,

Please check your cleaning whether scales are not properly removed. If hardened,heat treated scales, you need to remove via Kmno4 treatment. Also check dangler in the barrel and make good contact. Check the Anode area also.

Regards,

P. Gurumoorthi
electroplating process chemicals - Chennai, Tamilnadu, India
March 5, 2008

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March 6, 2008

Hello,

which type of zinc plating you are using? What are the geometrical condition of the parts? Any agitation?

Cheers,

Dominik Michalek
- Mexico City, Mexico