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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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What black chromate coated cadmium should look like
I'm looking for someone that can help me with black chromate coated cadmium. All the parts we have look as if they have a bad coating where we can see the cadmium below the chromate.Is this what they look like,no one here knows or remembers.
Aaron DowneyMetalurgist Trainee - Decatur, Alabama
July 14, 2009
Some more information would be helpful. Did you specify a chromate coating? A trivalent coating (ROHS compatible) or just a black finish?
Basically the black finish should be all black completely covering the part. The finish should conform to a specific Mil or ASTM spec for corrosion resistance. If you see the plating it is possible the parts were improperly processed or that scratching has occurred on parts after finishing. Non chrome black conversion coatings are more prone to this type of problem unless a top coat such as a wax or lacquer is applied.
process supplier - Great Neck, New York
July 17, 2009
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