Anxiety With A Great Coin !!!!

[GB_Amateur]

5 hours ago, dogodog said:

The key factor for me is being washed with water and then exposed to air.  I believe that it makes the surface more fragile. In my early days of hunting I would start out with a decent coin, Wash it and a week later it was unreadable and the surface was crusty.

This might indicate a different solvent (e.g. oil or alcohol) could be used instead of water.  I know there are some who feel all solvents are bad.  I'd really like to know the chemistry here.  Your mention of pH of the soil (remaining on the coin) when combined with water (releasing the OH- or H+ ions) attacking the copper certainly has to be a candidate culprit.  This shouldn't happen with oil unless it harbors (disolved) water.  But that begs the question why it doesn't happen 'naturally' when the coin is in the ground all those many years.  (Maybe it does, but then the damage would already be done and cleaning with water just exposes it.  And it could be a rate of reaction issue -- lots of water increasing the rate by orders of magnitude, which is where chemists could help explain.)

Experimentation on my ToDo list....

 

[Joe D.]

    Oxygen speeds oxidation in most all organic and inorganic materials! While different soils, clay's, and slits with various moisture levels, have their own preserving, or oxidizing effects! Ph, ozone, and minerals also play key rolls! But oxygen is the main culprit!👍👍

[dogodog]

Joe, you explained it exactly right. Low oxygen deep in the soil and odd and complicated soil make for some coins to survive. Just a note, My deeper dug coppers 9'' to 10''+ are most always in better shape. 

[Raphis]

Great coin find! 👍🏼

I’ve always had good results putting my crusty/caked dirty copper items in bubbling hot hydrogen peroxide.  I certainly can’t take credit for this technique.  (I’ve seen this “copper enhancement“ technique used on old coppers by countless treasure hunters on various detecting forums for over a decade.....

The technique is to place a small pyrex cup filled with a 1/2” of hydrogen peroxide in the microwave until you see it start to bubble/boil.  Remove the cup from the microwave and immediately place the coin in the peroxide (and watch it bubble/fizz). A lot of tough, caked on dirt/crud will start to come off into the peroxide.  It will sizzle for quite some time (minutes). I’ll repeat the same above steps after 3-4 minutes (or until the fizzing is barely noticeable) for the other side of the coin with fresh peroxide.  This process does not mess with the color/patina of the coin...

You’re correct about oil darkening the surface of copper....and once you put oil on the coin, there’s no reversing the effect......and I definitely agree with you about avoid placing water on the coin.....water does remove quite a bit of “detail”, and depending on the mineral content in the water, it can really cause the surface of the copper to become more prone to rapid oxidation.

[dogodog]

Raphis, Can you post a before and after pic with the peroxide treatment? Would love to see the results. I'm always looking for ways to clean my coins in a non destructive way.

[F350Platinum]

20 hours ago, Raphis said:

Great coin find! 👍🏼

I’ve always had good results putting my crusty/caked dirty copper items in bubbling hot hydrogen peroxide.  I certainly can’t take credit for this technique.  (I’ve seen this “copper enhancement“ technique used on old coppers by countless treasure hunters on various detecting forums for over a decade.....

The technique is to place a small pyrex cup filled with a 1/2” of hydrogen peroxide in the microwave until you see it start to bubble/boil.  Remove the cup from the microwave and immediately place the coin in the peroxide (and watch it bubble/fizz). A lot of tough, caked on dirt/crud will start to come off into the peroxide.  It will sizzle for quite some time (minutes). I’ll repeat the same above steps after 3-4 minutes (or until the fizzing is barely noticeable) for the other side of the coin with fresh peroxide.  This process does not mess with the color/patina of the coin...

You’re correct about oil darkening the surface of copper....and once you put oil on the coin, there’s no reversing the effect......and I definitely agree with you about avoid placing water on the coin.....water does remove quite a bit of “detail”, and depending on the mineral content in the water, it can really cause the surface of the copper to become more prone to rapid oxidation.

I'd like to see that too.

[Raphis]

4 hours ago, dogodog said:

Raphis, Can you post a before and after pic with the peroxide treatment? Would love to see the results. I'm always looking for ways to clean my coins in a non destructive way.

 

2 hours ago, F350Platinum said:

I'd like to see that too.

This may not be the utmost best example, but observe the 3 Indian pennies in the pics...One pic is before cleaning with peroxide; the other is after the peroxide bath.  I may or may not have used a bamboo toothpick after the peroxide bath to remove any really stubborn dirt/clay.  I also don’t remember how many times I repeated the peroxide bath on the 3 indians.  I do remember placing all of them in the Pyrex cup at once, with ample space between them.

[Raphis]

Here’s a couple more Indians:

 

 

[GB_Amateur]

On 6/22/2021 at 12:14 AM, Raphis said:

I’ve always had good results putting my crusty/caked dirty copper items in bubbling hot hydrogen peroxide.

Are you referring to pure hydrogen peroxide or a solution of peroxide dissolved in water?  I can buy 3% peroxide at Sam's Club (and other places) for quite cheap.  Getting pure hydrogen peroxide I assume means going to a chemical supply outlet (and maybe even being required to provide some kind of credentials).

[Raphis]

4 hours ago, GB_Amateur said:

Are you referring to pure hydrogen peroxide or a solution of peroxide dissolved in water?

Just the regular, easy to get at any drug store, peroxide.