Numismatic and History Discussions > Roman Coins

Bronze Disease / Bronze Plague? Solutions... workaround...


Prieure de Sion:
I bought this Nero Dupondius at an auction today. Since I only bought the coin today - I only have this picture, of course. Only when the coin has reached me will I be able to make precise statements about the detailed condition - whether, for example, the feared areas are a hard malachite patina or rather a powdery bronze plague.

I have received a hint for this coin - that it could be bronze plague on the reverse at about 11/12 o'clock.

Now I have never had anything to do with bronze plague and I immediately went to Google and tried to find clear instructions and information. But somehow - it is mentioned again and again that you could do this or that, maybe try this or that - but somehow there are no instructions anywhere. BTA is also advised - but I can't find any instructions on how to use it. Even how to apply everything is only roughly described.

Therefore, as a BEGINNER, here are my questions about possible bronze disease and restoration!

From what I now think I have read - if it is bronze plague, here is how I proceed:

a) I remove the coarse pieces with a toothpick.
b) With a hard small brush I remove the possible rest.

And now...

c) Do I boil the coin in a bath of distilled water and dry the coin? Or...
d) I put the coin in an acetone bath?

After that...
e) Do I treat the coin with BTA?

But what does "I treat the coin with BTA" mean? Do I apply the BTA with a small brush only to the said / feared area? Do I put the whole coin in a BTA bath? And if I put the coin in a BTA bath - how long does the coin stay there? And after the bath, how long does the coin have to dry? Air dry or dry with a hair dryer?

In short, as you can see, I have no idea about the bronze plague. It would therefore be very kind of you if an expert in the field could tell me:

1. Do you also think that this could be bronze plague?
2. Can an expert give me an exact order of how to proceed against the bronze plague step by step in detail?

Many thanks

Ken W2:

Hello. Those lighter green spots could be BD but most of the green encrustations look hard and ok to me.  If you think it’s BD you’ll find lots of info here on FORVM about using sodium sesquicarbonate to treat BD.  It’s inexpensive and safe used in a 5% solution.  I would not boil in it though. 


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