Letter 20002

Parts are burning out from alkaline zinc tank

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Parts came out from alkaline zinc tank burn at high current desity area' the burn looks like white powder. The temp. in tank is 85 F and zinc metal 1.2 oz/gal and caustic potash concentration is 20.0 oz/gal. we are using brightner and starter( refine rack ). All parts are burning on rack but bottom and side parts are more burning. Current density , we are plating 19 to 26 amps/sq.ft.

Popat Patel     plating shop Roseville, Michigan

Dear Mr PP,

You need to up the Metal conc to up to 2 oz/gal and also ensure that the NaOH does not exceed what you currently have. Mantain a metal : OH ratio of 1:10 and you will regain control.

Khozema Vahanwala Saify Ind   Bangalore, Karnataka, India