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Why is paint peeling off from brass base during silver plating?

2007

Dear Everybody,

We use Etching on brass. After etching we fill paint in the etching Cavity followed by proper degreasing and silver plating. But after silver plating the paint is peeling off from the base. Is this anything to do with activation of brass panel or something else? please be Brief

Shafiuddin A. Mohammed
metal coating shop - Dubai, United Arab Emirates

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I think it takes a very capable paint to stand up to degreasing followed by immersion in a strong cyanide silver bath! What kind of paint is it?

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2007

How well do you desmut the etched area before the application of paint?

James Watts
- Navarre, Florida
2007

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2007

Dear Sir,
We are manufacturers of medals and badges. Our products demand colours and paints on brass metal. But, after painting or coloring, the color is peeling off in the silver bath. Previously I thought it was due to cyanide conc. and I reduced the cyanide conc. to optimum. but still facing the same problem. And even after micro etching the brass pieces before painting in the ammonium sulphite solution.

Please suggest and be concise.

Dear Mooney,

The paint we use is RAL Paint

Shafiuddin A. Mohammed
metal coating shop - Dubai, United Arab Emirates

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It is not really clear to me what you are trying to accomplish.

Are you attempting to plate the paint? Or, are you try to save on silver by painting, first, the surface that is to be painted?

If the former, you need a coating that isn't paint. If the latter, the cost of the silver that's going to cover that surface is trivial, compared to what it's going to cost you to come up with a masking material/process that's going to stand up to 8 - 10 oz/gallon KCN. That's about as low as you can get away with running one of those baths and still get good plating.

Just plate the whole thing, then paint it, is my advice.

Dave Wichern
Consultant - The Bronx, New York
2007