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Q&As since 1989


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What media and liquid for polishing silver coins in a vibratory finisher?

Q. Dear sir we are manufacturer of gold and silver coins.
I have a vibrator for polishing, and we are using steel media.
I want to know which chemical to use for better result in silver.

Kaushal Patni
coins manufacturer - Ahmedabad, Gujarat, India
March 18, 2010

A. If you want to process coins in a wet system, you do not want to use abrasive ceramic media. That is used for metal removal. You need a non-abrasive media or porcelain. Any non-abrasive process is called burnishing or lapping. Almost any acidic chemical compound will produce good results, but should have a good inhibitor to prevent oxidation after processing and care should be taken in handling for the same reason. I prefer dry organic media treated with an aluminum polishing compound.

AF Kenton
retired business owner - Hatboro, Pennsylvania
March 29, 2010

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Q. I am using steel media in vibrator with local industrial shampoo.
After burnishing, the coin is rinsed in plain water, but some sticky layer of shampoo is not removed from silver coins.
So I want to know which detergent or powder we can use.

Regards,

kaushal patni [returning]
- ahmedabad, gujarat, India
June 13, 2017