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  for Metal Finishing since 1989
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Adhesion problems

We are experiencing adhesion problems between sulfamate nickel and acid copper. The adhesion loss is mostly in the low current density areas. I wonder if anyone has suggestions

Donald G. Brown
- Paducah, KY, McCracken
2003

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Try entering the acid copper with the current on. Make contact to the rack before entering the tank. The voltage should be higher than normal plating voltage (CD) to cover the low CD areas quickly. If it takes any small amount of time to start electroplating an immersion (chemical replacement) deposit takes place that always has poor adhesion. Another method is to use a cyanide copper strike prior the acid copper (with good rinsing and a mild sulfuric acid dip) There are also non-cyanide alkaline copper strikes that could work as a pre copper to prevent immersion deposits.

Don Baudrand
Consultant - Poulsbo, Washington
(Don is co-author of "Plating on Plastics" [on Amazon or AbeBooks affil links]
           and "Plating ABS Plastics" [on Amazon or eBay or AbeBooks affil links])
2003