cleaning copper/bronze

[Moe (fl)]

I have been using the aluminum foil, washing soda, and boiling water to clean some copper coins and it seems to only partially work. This procedure removes most of the green corrosion but then turns part of the coins dark brown or blackish. Is this what is supposed to do? How can I remove the dark brown tone or is this the way it should look?

Thanks.
Moe

 

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[Bob Z.]

The best way i have found to clean is to wash the coin with spray penatrating oil then work it in with a pencil eraser a few times. then wash with dish soap and dry.Now scuff with med.grit 3m scotch bright pad. Repeat this process if necessary Then put one drop of oil to each side and buff. Good luck Takes about 15 min. per coin. .Bob

 

[BuckleBoy]

This method is the best for old copper coins--ESPECIALLY the ones you need to identify.  You don't want to ruin a valuable coin.  Scotch brite pads will ruin a colonial copper or key-date Indian Head Cent.  The link is below:

http://forum.treasurenet.com/index.php/topic,39135.0.html

Here's my before/after post with a copper-nickel Indian Head dated 1864, as well as some Large Cents:

http://forum.treasurenet.com/index.php/topic,117293.0.html

Once you've used baking soda on them, I don't really know what can be done...

Oh, and some folks like olive oil on this forum...I don't like it, because it soaks into the coin, and then slowly leaches out for years.  The method in the above posts will not work if the coin has been in olive oil.


Hope This Helps,


Buckleboy