Coin Cleaning

I have a couple of questions? These are honest questions as I really don't know.
Is it OK to clean your coins with mild soap and water? I have some coins found in change from stores that were dirty so I used hand soap and water to clean them. Is this OK?
I remember back in high school, my old Taco Bell days, that we use to take old dirty pennies and put them in a packet of hot sauce, let them sit for 24 hours or so and then walla, clean shiny pennies. Is this bad or could I do this with old coins that lack luster? It just a mild acid in the tomato sauce. Does this affect the coins value and is it considered and unacceptable way to shine them up?

Thanks for your time.

Patrick

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Permalink Reply by Coin Docere on November 24, 2009 at 10:31am

clean or not to clean???? In my opinion....if the coin value is next to nothing why not....we are programed/wired to experiment..I have been doing conservation and preservation work for 10 plus years on coins...I have seen what some so called professionals have done to rare coins...(can you say butcher or mal-practice)...I have seen alot of doctored coins as well...usally once the damage is done..it's too late...unless you have the funds...I mean alot of $$ to correct the mistake...I usally tell my clients if they need to clean..use a very mild soap (soak) with dis-stilled water..(sometime I will place on the range and boil for a few minutes and let cool) then let (pat)dry...(you can use toothpick very lightly to pick gunk)..if you are not sure of yourself..DO NOT DO IT!!! Clair Alan Hardesty reply is a good answer... hope this helps

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Permalink Reply by Indentured Servant on November 24, 2009 at 9:12pm

How about an ultra-sonic or mega-sonic cleaner? I polish (non-abrasively) both indium and gallium based wafers that my company manufactures. Both materials are many orders of magnitude softer than any metallic coin in existence. From time to time we will get a stubborn stain on a wafer and we use both ultra-sonic and mega-sonic cleaners with various solvents and surfactants. We routinely inspect these wafers with 1000x magnification and see absolutely no degradation in the surface which has been polished to better than 3 microns (30,000 angstroms) surface roughness.

I can see how one of these methods might affect patina depending on the bath ingredients used but there is no way that mechanical damage could be done. The olive oil technique metioned certainly intrigues me. Combining that with ultra of mega-sonic might be interesting. I wonder what would happen if the oil went rancid?

Does anyone have any insight regarding "approved" cleaning methods used by professionals?
Bill