NO!!!!! The dreaded BD :(

Hi everyone,

I think I've caught a case of the bronze disease on a coin.

There's a build up of lime green powder in the slit. I just went in there with a pin and it started coming off.



I was wondering if you guys could help me. I've never dealt with BD before, so am clueless.

Thanks!

Erin

 

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Erin are you in the US?

 

Hi Pishpash,

I live in Canada.

Erin

 

Looks like a Judaean, which are prone to BD. One has to remove it manually. I use a wooden toothpick so as not to scratch the surface of the coin itself. Scrape it out until you get to metal. Use distilled water to rinse it off, then scrape again. Rinse again, etc. Do it as many times as you can guess that it is gone (some people heat treat the coin afterwards, just in a low heat oven). When done, check it at least weekly for maybe a year. Thats the basic explanation. I know there are those who use chemicals and other methods, but one has to be careful about it lest you destroy the coin.

 

The only thing I would add to Ken's advice is to seal it with Verdicare once you're done cleaning it. Prutoh are notorious for bronze disease. I won't sell them unless I've had them for a while and they appear to be stable.

 

Kevin's advice is good. Personally, I would just clear it out very thoroughly with a brass brush and see if it comes back, not washing it with DW or anything.

 

Others have posted some great advice with respect to cleaning the BD. Going forward however, I recommend you pick up some of these: https://www.amazon.com/10g-Silica-G...UTF8&qid=1468336834&sr=8-1&keywords=Dessicant

I keep them in all of my coin boxes and recharge and replace regularly. If I send a bronze coin outside the US I throw one in the package as well.

 

Thanks for the advice, everyone. I really appreciate it!

That totally sucks that Judaean coins are prone to BD. I have a bunch on my wishlist.

I tried getting a tooth pick in the slit, but it didn't fit, that's why I used the pin to test it.

I'll get some distilled water on the way home. I'll order some Verdicare on payday.

I did get a bunch of silica gel packs from eBay. I have a binder that I keep my coins in and have put one in each coin sheet. I guess I didn't get them in fast enough. :/

You guys rock!

Erin

 

It doesnt really matter if you had gotten that silica in there earlier or later. It would have developed anyway. Keeping the humidity out can slow it and possibly prevent it in the future, but likely it was already there and you couldnt see it. It is one reason why base metal coins should be examined every year.

 

Yeah, I am due to go through my holdings in the SDB and check for reoccurences.

I scrape what I can with something softer than bronze, then treat with VC. If it appears stable I coat with Renwax.

 

Coating coins with wax can be a good thing, but just one caveat: If the problem is still there the wax will preserve it and it will continue. Another thing to consider. While it is not an organic problem like some think, it can easily be transferred from one coin to another if they are touching. Make sure it is isolated and does not come into contact with another coin. I once had a big bag of Judaean coins which I ignored for a bout a year. When I finally looked at them about a year later about a third were infected. I donated them to a guy who properly cleaned them and put them into the ACE Project.

 

See also Wikipedia for a good exposé about what BD is and how to treat it.

 

@Johndakerftw

HOLY CRAP! DON'T TOUCH THAT COIN with a wire brush. Where do these "Experts" crawl out from? The green patina is beautiful. You have been advised by sensible collectors how to remove the BD.

Soak the BD spots in Coin Care or VC and use sharpened toothpick, thorn, or plastic point on the BD spots rather than a metal tool. The coin liquids will loosen the crud.

 

Um, you do know sir do you not that brass will not harm a bronze coin. Brass is much softer than bronze, so the brass at worst will leave brassy marks on the bronze that can be removed. I use brass tools all of the time on bronze coins, most ancient collectors do.

Now, do you HAVE to use a brass brush on this coin? No, but if it will not come off with wood or plastic, and its still too think for VC to properly treat it, then I would use a sharpened brass tool to dig it out. If you wish to call me a so called "expert", then we can discuss. I was shown how to use brass tools on bronze coins by some of the biggest names in ancient numismatics.

However, overall, start with the least damaging approach. Start with wood and plastic and see if it will solve it. I am just saying if they do not work, (and I have had times they wouldn't), then there is nothing wrong with silver or brass tools on bronze. Of course, never use brass on silver or gold.

 

Um, you do know sir do you not that all your scrubbing with a "soft" brass brush shows up under my stereo microscope. My family was in the jewelry/watchmaking industry so I'm familiar with "tools of the trade" such as brass brushes. Humm, I may even have a few of these around that are well broken in.

So....you, your buddies, and the biggest names in ancient numismatics can keep scrubbing along. That's just another reason 99.99% of the ancients we all love ARE NOT ORIGINAL! Now, excuse me while I try to "fix" some coins that were ruined by "experts"

PS I am 100% in agreement with most of your last two paragraphs!

PSS As I have posted several times before: You and the ancient collectors on CT know more than I shall ever know about ancients when it comes to identifying them. Nevertheless, I'll put my skills on par with any of the biggest names in ancient numismatics on some subjects in this field.

 

Just my two penneth, I have ruined a couple of coins by using a brass brush

 

No expert here but I do know that you do not know what metal was used for your particular coin. We tend to throw around terms like bronze and brass rather freely but we also know that coins we call bronze can have components not on the standard list for that modern term certainly including silver which can change such things as hardness before it does color. Then we have the question of patina which may or may not be scratch resistant to a known degree. Of course we are assuming that tese brass brushes are actually brass and not those brass plated steel monsters I have seen sold in places we should not be buying coin supplies.

My favorite coin pick is a splinter of ebony wood left over from my days as a wood hobbyist. I see plastic picks sold for some non coin uses that make me want to try one but, like everything else, not all things plastic are the same and making something plastic with embedded diamond dust is well within modern technology but not something I want.

Long ago, an old collector told me that the way to cure scratches was to replace them with a hundred small scratches. I think we call that smoothing and tooling today. He was a specialist in Athenian silver which will scratch if you look at it wrong. I also think of those brushes they sell to use on cars that warn that they will not scratch the paint but that they will get dirty and that dirt certainly will scratch. Never say 'won't scratch'.

 

Does anyone in Ancients collecting use a stereo microscope? curious...

 

Of course most ancients are not "all original". The only coins that could ever be collectible straight from the ground are gold coins. EVERYTHING else has been cleaned already. A lot of that cleaning was done with brass. Rose thorns do not cut it for most ancients.

Honestly, I believe the OP's coin might do better with a thinner patina anyway. I would need to see it in hand, but many ancients develop way too thick of a patina, and the patina obscures details underneath. A great many coins are improved by removing part of the patina.

So I don't know about your skills in improving modern coins, they could be spectacular, but for ancients many times removing patinas, using sharp tools, etc are part of the improvement process.

Doug's points are valid. You never know about brushes until you test them on coins. I don't even really use brushes, I use sharpened pieces of brass if I need to get serious about something on a coin and wood, plastic, distilled water, etc have failed. I think it was just @Insider seeming to make fun of the idea of using brass as some kind of barbaric act that set me off. Ancient collector conserve our coins a different way, we have much more severe problems to deal with, than collectors of modern coins do.

 

I do. I have a 8/16/32 power stereo microscope I use.