Returning old copper to it's former glory

Billet7 · April 14, 2011 4:30AM

We recently had a thread regarding storage of a silver coin, with the intent that it tones back to an original (ish) look. In almost all cases, it takes time. Is there a similar time intensive method that will return copper to a more original state (without the aid of recoloring) that will not damage the surfaces but will subdue that terrible looking bright coppery look? I don't know of any methods (course I've never really tried either.)

Discuss!

jmski52 · April 14, 2011 4:44AM

If a coin's been cleaned, no amount of re-toning will restore the original luster because the flow lines from the strike are what gets wiped out when the surface metal is cleaned or reacted & removed by stripping.

It just isn't going to happen.

MikeInFL · April 14, 2011 4:48AM

Dellers Darkener will retone copper. In the hands of an expert the results can look pretty good, but typically it results in a very even brown coloration you often see described "smooth chocolate brown" which is code for "recolored".

Another method is to simply handle the coins with your hands on a regular basis and/or put them in your pocket. Copper is very reactive and retones naturally quite well in this fashion (if you don't mind the coin losing some detail and/or being beaten up a bit).

A few other methods (which I have not personally tried) include Vaseline infused with sulfur, putting coins on windowsills, and I've even heard of putting them in a potato.

Hope this helps...Mike

p.s. jmski, You are correct that once the luster has been impaired, there's no going back. That said, copper can absolutely be dipped/cleaned without affecting the flow lines, just like copper/gold/nickel, etc. Provided you don't clean it abrasively/harshly or leave it in the dip too long, of course.

Tdec1000 · April 14, 2011 5:58AM

<< <i>Dellers Darkener will retone copper. In the hands of an expert the results can look pretty good, but typically it results in a very even brown coloration you often see described "smooth chocolate brown" which is code for "recolored".

Another method is to simply handle the coins with your hands on a regular basis and/or put them in your pocket. Copper is very reactive and retones naturally quite well in this fashion (if you don't mind the coin losing some detail and/or being beaten up a bit).

A few other methods (which I have not personally tried) include Vaseline infused with sulfur, putting coins on windowsills, and I've even heard of putting them in a potato.

Hope this helps...Mike

p.s. jmski, You are correct that once the luster has been impaired, there's no going back. That said, copper can absolutely be dipped/cleaned without affecting the flow lines, just like copper/gold/nickel, etc. Provided you don't clean it abrasively/harshly or leave it in the dip too long, of course.

>>

Vaseline infused with sulfer is essentially dellers darkener.

Billet7 · April 14, 2011 2:23PM

Do you just get sulfur at the nearest chemical shop and mix it in some Vaseline?

Tdec1000 · April 14, 2011 3:01PM

<< <i>Do you just get sulfur at the nearest chemical shop and mix it in some Vaseline? >>

I have no idea, all I know is that dellers is made from a vaseline type base with a sulpher or sulphide in it.

EagleEye · April 14, 2011 3:10PM

MikeinFla , I don't see "chocolate brown" used except to describe an original brown coin, so I think that is a bit of misinformation. A recolored coin is usually described as something else, since recoloring can be many shades, whereas chocolate brown can only mean one thing - original color.

robkool · April 14, 2011 3:28PM

Blue ribbon works great... I use it on my medals & tokens.

Pistareen · April 14, 2011 3:35PM

Not to pile on, but I'll agree with Rick -- in the hundreds (thousands?) of times I described something as "smooth chocolate brown" in my cataloguing, I never meant it as a euphemism for recolored.

Coins toned with Dellars or any other kind of fairly crude sulpher method will often have a bit of a matte appearance, rather than the nice gloss of smooth circulated copper.

Frankcoins · April 14, 2011 5:39PM

Copper recolored with Dellers Darkener or sulfur are almost always an ugly blackish color with various dark brown or even bluish casts. The color will often rub off easily.

I never have heard of retoned copper called chocolate brown, which is natural toning, pretty, not easily faked, and protective.

MikeInFL · April 15, 2011 3:58AM

Rick, John, and Frank, I am not referring to people like you (that both have scruples and who know the difference) when I said "often", and I apologize if you took it differently -- that was not my intent. What I was referring to are less-scrupulous sellers and inexperienced collectors who simply look past or don't know the difference between recolored brown and natural brown (as is often seen on eBay as in this example and, without naming names, even in posts on this forum), and I stand by what I wrote. Respectfully....Mike

Returning old copper to it's former glory

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