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Author Topic: Bronze disease and the danger of waxing  (Read 4276 times)

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Offline moonmoth

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Bronze disease and the danger of waxing
« on: August 10, 2009, 09:32:30 am »
Many collectors, particularly those who clean their own coins, wax them before storing them.  Some sellers wax their coins before selling them.  But this can be dangerous if it is done willy-nilly, without a careful inspection of the coin first.

I bought this coin recently and I thought at once that it had spots of bronze disease. There was already some pitting, and lots of the typical light grteen spots. (This is the photo labelled As Bought). So I gave it the usual treatment, an hour's simmer in sodium sesquicarbonate solution. This is usually completely effective, but on this coin it did not make very much difference, which I thought odd.

Looking at the coin, I suspected that it ghad been waxed, either by the seller or by whoever he obtained it from. I wondered if the wax was protecting the bronze disease, so I soaked it in white spirit for a day (this is called Stoddard solvent in the USA), washed it off and gave it another simmer in sodium sesquicarbonate.  This is the photo at stage 1.

This was better.  Clearly, some significant pits of bronze disease had been cleaned out.  But still there were some lingering signs, so I went through the whole thing again, wondering by now if there would be any patina left after all this soaking and boiling.  The white spirit turned green this time, suggesting that I was starting to remove something containing copper.  White spirit will only dissolve oil-based substances, not patina or raw copper, so now I was starting to think that someone had applied a stain to the coin as well as wax!

This is stage 2.  The two photos of the whole of the obverse are "as bought" and stage 2. I think I have now completed the task of clearing out the bd, and without making much difference to the overall appearance of the coin.

Now, because there was already some pitting when I first got this coin, it is quite possible that someone had treated for bd before applying probably a stain and definitely wax.  But if so, the job was not well done. Bronze disease was rampant beneath the wax coat. This is one major reason why I do not like wax.  It made my own treatment much more difficult than it should have been.  Those who say "Clean, wax and flip" should just be saying "Clean, brush and flip!" 

I de-wax quite a few coins when I get them, even if they look fine, so that I can take a decent photo without the shiny wax surface getting in the way - this is the other reason I don't like wax.

Good quality wax makes a coin shiny and slippery.  Bad quality wax does this and also hangs on to lint, making a coin almost impossible to clean off. 

But enough ranting; on to the photos ... click to enlarge.
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Offline Heliodromus

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Re: Bronze disease and the danger of waxing
« Reply #1 on: August 10, 2009, 09:53:45 am »
Interesting - a good precautionary tale.

Not only does the coin appear none the worse for the treatment, it actually looks better de-waxed.

Ben

Ghengis_Jon

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Re: Bronze disease and the danger of waxing
« Reply #2 on: August 10, 2009, 10:02:11 am »
Most coins do.  Waxing tends to highlight flaws and intensify even the slightest of roughness.

But they look nice in hand...

Offline areich

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Re: Bronze disease and the danger of waxing
« Reply #3 on: August 10, 2009, 10:02:54 am »
I absolutely hate the look and feel of a waxed coin.
Andreas Reich

Offline Will Hooton

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Re: Bronze disease and the danger of waxing
« Reply #4 on: August 10, 2009, 10:08:36 am »
I had a small bronze from Side which when recieved was waxed. I left the coin in my tray and left on a long contract abroad. I returned to find the thing absolutley caked in BD! I only managed to recover it with great difficulty.

Im not entirely against waxing. It works with some coins but not with others.

Offline bruce61813

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Re: Bronze disease and the danger of waxing
« Reply #5 on: September 12, 2009, 10:19:20 pm »
I had a small bronze from Side which when recieved was waxed. I left the coin in my tray and left on a long contract abroad. I returned to find the thing absolutley caked in BD! I only managed to recover it with great difficulty.

Im not entirely against waxing. It works with some coins but not with others.

As you noticed, waxing does not stop or fully protect a coin with BD. I can help other coins from becoming contaminated by the BD powder. If you even think the coin my have BD, I recommend starting treatment, if only sodium bi-carbonate and water. That will help some, but  it is easier to start the full treatment or soaking process. Then if you must travel, the condition will be stopped, or at least held in check until you can spend time on it.

Bruce
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Offline Enodia

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Re: Bronze disease and the danger of waxing
« Reply #6 on: September 12, 2009, 11:41:08 pm »
I absolutely hate the look and feel of a waxed coin.

i couldn't agree more.

 

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