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White wash deposit after chrome plating
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What causes white wash deposit on wheels after chrome plating aside from low ratio of Chromic acid to Sulfate concentrations in Chrome solution?
Thank you.
Louie RumbaughLab Supervisor - Carson, California
Ed. note: Send a good photo to mooney@finishing.com if you can, Louis. Maybe what you are calling 'white wash' someone else might call haze (or maybe not).
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If by deposit you mean a salt layer, will it wash off with DI water? If it is and it has been baked on, it may take a very dilute acid to get it off.
My guess is that it is a haze or milky plate which can also be caused by the amperage either too high or too low for the tank temperature; or another catalyst that you might be using being too low.
- Navarre, Florida
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Might we not be looking at a passive nickel problem, requiring cathodic activation in acid or cyanide prior to chrome plating.
Geoff Whitelaw
- Port Melbourne, Victoria, Australia
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Try two simple fixes first -
1. Improve rinsing after nickel.
2. Let the part come to temperature for a short time after immersion in the chrome solution before applying current.
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Jeffrey Holmes, CEF - Spartanburg, South Carolina |