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  for Metal Finishing since 1989
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Brass over zamac

I have a lot of problems with electroplating brass over zamac like small brown points that appear over the plated surfaces after few days. I use Cr+6 non electrolitic during 10 seconds over brass but the results are not so good.

Paulo
- Caxias do Sul, RS Brazil
2003

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Your brass plating as being cyanide based, are like all cyanide solutions, very prone to "bleed out", therefore clean and adequate rinsing is the key to prevention of the so called black spots or spotting out. Possibly the problem is really in the rinses after plating, instead than ahead into the process. Magic solutions like Chrome+6 dips do not help unless you improve dramatically your post rinses.

Glad to be at your services.

Domingos J C Spinelli
- S.B.Campo, Sao Paulo, Brasil
2003