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Electroplating corrosion

We are facing problem with Zinc clear passivated components getting failed in salt spray at 24hrs .The passivation is Hexavalent.How to improve.

BABURAJ
MANUFACTURING - INDIA
2005

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Clean them correctly, plate them correctly, and conversion coat them correctly. Although this answer is facile, and not particularly helpful, the point is that the problem could be absolutely anywhere, many full length books have been written on the subject, and the expected salt spray life may not be much greater than 24 hours, so everything must be right. Can the parts be yellow chromated? That would offer you a fatter safety margin because the salt spray rating is much higher. Can the parts be treated with a water soluble wax or lacquer or a topcoat?

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2005

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

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Dear Mr Baburaj,

Why don't you try trivalent chromates with top coat gives sst life of 120 plus hours. Environmentally more safe. We have to look more hexa free chrome in future. In India trivalent chromates are available with higher sst life. contact chemical supply house.

P. Gurumoorthi
electroplating process chemicals - Chennai, Tamilnadu, India
2005