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Want to strip trivalent chromate but not the zinc plating

as we have non-cyanide zinc bath the plated component is dipped in trivalent passivation and the same job got rejected due to some reasons I want to remove passivatio only without affecting the plating tell me is there is any way.

Jacf Peter
manager - India
January 15, 2009

You can remove it by caustic soda [affil links]

Hatem Shaker
- Cairo, Egypt
January 21, 2009

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You have to be very careful using caustic as it will also remove the zinc if left in too long or if the caustic is too strong. Consider using a 1 pound per gal of bicarbonate of soda at about 100F and then add tiny amounts of caustic soda [affil links] to increase the rat of reaction as required.

Also, You can wet blast the chromate off. We had a wet blast cabinet and added a handful of 600 grit aluminum oxide and a couple of ml of liquid soap and it worked extremely well.

James Watts
- Navarre, Florida
January 23, 2009