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Powder for removal of excess galvanized zinc

Sir, I was told that there is some powder if we sprinkle it on the heavy piece after hot dip galvanising, the extra zinc automatically leaves that piece. HOW FAR IS IT TRUE. AND WHICH IS THAT CHEMICAL. THANKS

Akash Deep Bassi
Plating Shop - India
August 6, 2008

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It could be that the powder is flux. (Zinc ammonium chloride).
While the zinc is still molten (as it is being withdrawn from the kettle), sprinkling flux powder will tend to fluidize the zinc causing the surplus to run off.

Its not wholly reliable, can cause flux staining, causes a LOT of fume, and can be hazardous to the operator.

Works best on mesh products.

Geoff Crowley
Crithwood Ltd.
Westfield, Scotland, UK

August 7, 2008

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August 10, 2008

Sir,
The powder you seek is ammonium chloride (formula NH4Cl). If you need this powder it is likely that your flux solution was poorly formulated, poorly maintained, and/or improperly used.
Regards,

Dr. Thomas H. Cook
Galvanizing Consultant - Hot Springs, South Dakota, USA

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October 4, 2008

The powder you are seeking is zinc ammonium chloride or just ammonium chloride,if just ammonium chloride is used causes lot of fumes but cheaper.
This is just like wet galvanizing where in the wiping action of the flux reduces the thickness of coating.

Best Regards,

S.R.Ameen
- U.A.E.