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Activation of silver plating
April 2, 2014
Q. I silver plate (.021" thickness) pump parts for the plastic industry and on occasion the thickness required is not met. I have been machining the silver plating off and starting again with base material. I would like to be able to silver plate over the existing silver plating to reduce time.
Tom Houvouras- Huntington, West Virginia USA
A. Hello Tom,
If you are using a cyanide based bath, a cyanide dip works fine. The concentration can be 4-6 Oz per gallon. Obviously there is no need to rinse after the dip, just make sure you have adequate hang time before going into the silver bath. This of course would be valid if the parts are soil free. If you are using a non - cyanide bath you would have to contact your silver bath supplier to find what they would recommend as formulations differ.
Process Engineer - Malone, New York USA
April 9, 2014
Q. The silver bath we use to silver plate is 4-6 oz per gallon.
We also have a silver strike that is .7 oz per gallon.Bath is cyanide. Also what is adequate hang time?
- Huntington, West Virginia USA
A. Hello Tom,
Sorry I didn't get back to you sooner, I've been having trouble with my router at home. Because you are using a Cn based Ag strike and final plate, many platers give the parts a quick soak (15 seconds) in the strike bath before they hit the cathode bar. There is enough Cn in the strike bath to activate the Ag. Again, this is sufficient when the parts are soil free. If you go this route, don't be concerned with hang time between the Ag strike and final plate. The chemicals you lose through drag out of the final Ag plate will be somewhat replenished when you drag in chemicals from the strike bath. Good Luck!!!
process engineer - Malone, New York
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