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Author Topic: BD in silvered antoninianus  (Read 2448 times)

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Offline JRoME

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BD in silvered antoninianus
« on: August 22, 2009, 10:09:10 am »
I just noticed this green spot on the edge of my Phillip I silvered antoninianus.  Does it look like bronze disease

Offline ecoli

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Re: BD in silvered antoninianus
« Reply #1 on: August 22, 2009, 01:07:53 pm »
does it come off easily?

Offline JRoME

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Re: BD in silvered antoninianus
« Reply #2 on: August 22, 2009, 01:22:37 pm »
I just tried scraping it with a toothpick and it crumbled at the slightest pressure.  That's not good is it.

I did a search for BD on silvered coins and could not find a thread on how to get rid of it.  I'm sure this must have been discussed before.

Offline Danny S. Jones

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Re: BD in silvered antoninianus
« Reply #3 on: August 22, 2009, 02:31:25 pm »
If it's crumbly and powdery, you need to treat it immediately. The simplest way is to remove as much if the green stuff as you can, then soak it in distilled water, changing it daily for a couple of weeks. Afterward, take it out and let it dry completely. Watch it for a few more weeks to see if it comes back. If not, seal the coin with ren-wax to help keep moisture out.

This may not work for coins suffering from really bad BC, but there are other methods you can use, some requiring chemicals.
Try these links to treating BD:
Bronze Disease
Bronze Disease Treatment

With that little spot, I'd try the Distilled water first, as it is the least harmful to your coin. Chemicals will more than likely strip your silver and (any patina) off of a coin.

Offline Joe Sermarini

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Re: BD in silvered antoninianus
« Reply #4 on: April 10, 2020, 08:47:38 am »
Bronze disease is unlikely to progress on a white metal billon coin. If it is white metal, I would not do anything that would damage the coin in the desire to preserve it.
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Offline Anaximander

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Re: BD in silvered antoninianus
« Reply #5 on: September 12, 2020, 06:41:31 pm »
I have a silvered antoninianus with some hard red and green encrustation on both obverse and reverse.  In perusing the discussion board for a solution, I came across several that seem to fit the situation.  

First: the diagnosis:  "Red incrustations are usually composed of Cu2O (copper (I) oxide)"
So, bronze disease?

Remedies...

1. "People say benzotriazole solution in ethyl alcohol is a powerful inhibitor of copper corrosion. Benzotriazole can be purchased here: (link)"

2. "[Put] into [distilled water] with Gringott's Bronze Disease Killer on a low boil, followed by a long soak/pick/soak/pick cycle. For cleaning, I alternate between a dental pick and a diamond tipped Dremel tool."   I've not heard of this product before, or seen it for sale.

3. "Ammonia will remove it, slowly.  The household ammonia will have to be changed after a day or two, and if it seems to stop working, it is probably because there is lime mixed in, so rinse, put it in vinegar for a day or two, rinse, and then go back to the ammonia."

4. "I would imagine a brief soak in lemon juice followed by a gentle rub would clean them off."

I've opted for solution #4 as the least aggressive approach, at least to start.  It was a good start, but not a runaway success. Here's the result in pictures: Before and After.

The red encrustation is still there, but reduced, and the coin is shinier.  I tried to chip away at the encrustation (blackening Q-tip ear buds).  I am tempted to leave as-is.  Suggestions welcomed.


Offline Akropolis

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Re: BD in silvered antoninianus
« Reply #6 on: September 12, 2020, 06:48:58 pm »
You did well.
I would stop.
PeteB

 

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