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world gathers for metal finishing
Q&As since 1989


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Zinc plating nightmare

I manufacture my own steel parts, but send them out for zinc plating. Recently I picked up a production run, and on the drive home it began to snow, so my parts got wet. A few days latter, the finish started coming off in patches, leaving powdery white residue. Can any one tell me what's happened, I wouldn't think a bit of moisture would do that. It would be great if someone could tell me the straight goods.

Thanks,

Robert Armes
- Brantford, ON, Canada
2002

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First of two simultaneous responses

The white residue is zinc oxide. The oxidation of your parts was accelerated by the salt that was put on the roads to melt the snow. This salty slush flew up as spray and mist as you drove along..

Todd Osmolski
- Charlotte, North Carolina, USA
2002

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Second of two simultaneous responses

Wet and in external contact with steel (truck bed) will cause white rust in a matter of days. Throw in a trace of salt from the roadway and you can have white rust in hours. Let me guess, no chromate coating or a clear or light blue.

James Watts
- Navarre, Florida
2002