Bronze Disease - Need Help

Your coin has bronze disease, not verdigris. Removing the green chemical salts and sealing the areas will only make matters worse. Here is why: once BD starts it sustains itself within the fabric of the coin. Sealing it from air and moisture does not stop the action which continues beneath the sealant. But the sealant does hinder your ability to treat the coin chemically.

The treatment which will stop the progress of bronze disease involves the use of sodium sesquicarbonate and a specific set of procedures for applying it and removing it. Unfortunately this treatment will also destroy some patina. The treatment is not worse than the disease when the BD is in its later stages and is forming pits. That is what it is doing to your coin.

the green deposits are the result of chemical action between the bronze and HCL

BTW- don't let this coin or the material on it make contact with other bronze coins in your collection. True BD is "contagious."

Here's the site I usually refer folks to for bronze disease treatment info: http://kevinscoins.ancients.info/BD...Disease.html

Before you go and buy chemicals you may want to try this. I've done this and it halted the progression of the disease. Place the coin in a 200 degree oven or under a lamp that will heat the coin to remove the moisture trapped in it. Once the coin is heated remove it quickly and place it under and air tight jar so the moisture does seep back into the coin as it cools. Once cooled you can remove what remains on the green deposits. Than you can give the coin a coat of REN wax. Simple but it works.

Thank you all of you!

I did both process twice! :D Just for sure, but I did not cover with wax.
The coin is still in quarantine, but looks ok!

I agree you did an excellent job.

Thank you!

Both side better in hand. Still some brownish patina remain.
I made a small trick. After I finished cleaning there were holes, where the metal was shiny. So I dripping liver of sulfur, to earn that darker area.




(If I am right the coin is "healthy" now, because I put water into the holes around a week ago, and nothing bad happend.)

"this is an excellent result. I am not familiar with "liver of sulfur" but it might just be interfering with the bonding of the chloride, substituting a sulphate or sulphide or sulphite ion."


He only used the liver of sulfur to darken the shiny bits, not treat the bronze dise ASE

Yes, I used that stuff only for coloring the naked parts.

Wikipedia:
"Liver of Sulfur is a poorly defined mixture of potassium sulfide, potassium polysulfide, potassium thiosulfate, and probably potassium bisulfide. Synonyms include hepar sulfuris, sulfur, sulfurated potash and sulfurated potassa.
Liver of sulfur is mainly used in metalworking to form a patina, turning copper alloys brown or black.
Typically liver of sulfur comes in a dry rock form which must be broken into smaller pieces and dissolved in hot water for use."

I do not like the color of this patina, but perfect if you want to correct small surfaces.
Of course I will post new pics a few months later.