Curated with aloha by
Ted Mooney, P.E. RET
The authoritative public forum
for Metal Finishing 1989-2025
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Problem with adhesion of silver plate
2000
Q. I am having adhesion problems plating silver to a nitrided steel. The silver plate has small blisters, which when peeled away show a copper strike. The process is:
- Soak clean
- Rinse in running water
- Anodic alkaline clean
- Rinse in running water
- Muriatic acid dip
- Rinse in running water
- Copper strike
- Rinse in running water
- Silver Strike
- Silver Plate
- Rinse in running water
- Hot water rinse and blow dry
It appears that the silver is not adhering to the copper strike in small areas. What could be the problem?
Daniel Bemenderfer- Indianapolis, Indiana
A. Since I can not see it, my first guess is that the copper strike has holes or pits in it that traps impurities which cause the later tiny blister. Try putting a thicker strike on it and see if that helps.
James Watts- Navarre, Florida
2000
A. Yes, and I wonder if the copper is having trouble with the nitrided steel. How about testing with a Wood's Nickel strike or Watt's nickel before the copper?
Tom Pullizzi
Falls Township, Pennsylvania
2000
A. Have you tried putting a potassium cyanide rinse in between stages 8/9 to activate copper? This will also stop a galvanic silver taking place in silver strike. A water swill is just not sufficient.
Keith Ager- Sheffield, S.Yorks, UK
2001
A. I think you have your silver strike badly contaminated with copper. If you see a small black point when it comes out of this bath, it's copper. You need another rinse between copper and silver, only one is too few.
Victor Esteves- Munich, Germany
November 8, 2014
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