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Painting over silver plate

2000

My name is Rob and I have been a process engineer in the microwave filter industry for 3 years. We manufacture small to medium "shoe box" size solid aluminum rectangular housings with milled cavities throughout. These boxes are used in the cellular industry and are silver plated for conductivity (200 microinches) over a nickel strike (100 microinches). During the assembly process, there is much handling so there is minor surface contamination (fingerprints) as they enter the paint shop.

The product has connectors which we mask and a lid which is fastened with 150 small screws. The filter is not hermetically sealed so immersion cleaning is not possible. We need to find a material and process that provides a black painted surface that will pass 96 hr salt spray, 196 hr humidity, and adhesion (tape) test. We currently use polyurethane over phosphoric acid etch primer with limited success. We are investigating water based one coat systems but are not sure about the consistency of adhesion to silver plate over this minor contamination. I have found no information nor research on painting on silver plated surfaces. It there any information available?

Robert McCulley
- Salisbury, Maryland USA

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First of two simultaneous responses-- 2000

Dear Robert,

Try a solvent Wipe, then spray with a two part Black Epoxy. The Epoxy takes about two hours to set if you air-dry. Or upon cooling if you can force dry @140 deg.F for 30 min.. Best regards,

Buck Nikolas
G. J. Nikolas & Co., Inc.

Bellwood, Illinois

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Second of two simultaneous responses--

Wipe the box down with a clean rag that is wet with isopropyl alcohol ⇦ this on eBay or Amazon [affil links] . Check with the major paint companies tech services for adhesion to silver.

James Watts
- Navarre, Florida
2000

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In Jewellery production, we are coating the finished silver with an electroplating system (Cathaphoresis): need to finish the treatment in a hot air furnace (30/45 min - 150°) Not change the base color of the Silver plated layer.

Feel free to contact us, for any other information.

Lino Zorzi
- Romano d' Ezz. (VI) Italy
2000

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Robert,

We have problems painting silver plated units. I have recently atempted a different approach with good results. I do a short low power Plasma spray. One of the gases that I used was 02, since it does a better "clean". This seems to have solved the problem. There is a minor tarnishing affect, but this might even be helpful.

Rafael Borenstein|
- Ashdod, Israel
2003

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If you have any suggestions of how I can touch up a sentimental piece of costume jewelry, please tell me.
Thank you, Nancy C

Nancy L Clampitt
consumer - Dallas City, Illinois, USA
2007