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Ted Mooney, P.E. RET
Pine Beach, NJ
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for Metal Finishing since 1989
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Black anodizing is velvety, and discolors when touched
Q. Hello, I am having issues with my black dyed anodising. When it is removed from the hot water seal and dried, it has a velvety look to it. When I touch it, it leaves finger prints, and when I take a thickness reading with my DFT meter, the point where I take the reading goes a strange greenish colour. Please help!
Gillian TraceyEmployee - Coleraine, Co.Antrim, N.Ireland
February 18, 2016
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A. First you have an anodizing problem, come back with alloy, prep-process, free acid, temp, and current density.  Robert H Probert Robert H Probert Technical Services  Garner, North Carolina  March 16, 2016 A. Sounds to me as if you're seeing seal smut. For dyed work, try using a mid-temp nickel acetate seal.  Marc Green anodizer - Boise, Idaho March 17, 2016 |
A. Gillian
The cause could be either anodize step or seal step related. To help determine, blow dry the surface of a couple of parts immediately prior to sealing and examine.
- Colorado Springs, Colorado
March 17, 2016
A. Good day Gillian.
I do not know the depth of your experience, but there is good info at
diyanodizing.com
like anodizing basics/dyeing.
Hope this helps.
Regards,
Aerotek Mfg. Ltd. - Whitby, Ontario, Canada
March 17, 2016
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