This medal/plaque recently came into my possession. The seller's photos very much downplayed the verdigris spots that blemish the obverse, and I'm wondering if there's anything that can be done to neutralize them and/or eliminate their spread? Also, I was unsure what forum to post this into. Do we have an exonumia forum that I'm just not seeing?
Nice, but is that bronze disease or verdigris??! I would drop it into hydrogen peroxide but no longer than 4 hours. Some will say distilled water but I doubt distilled water would work. The thing about using hydrogen peroxide is it will definitely change the color of the metal if you leave it soak for longer than 24-48 hours! Acetone? I don't think it will work but heck I've been wrong plenty of times on this forum!
Thanks. I was thinking about acetone. But I'm not sure how it reacts to copper or bronze. Anyone have experience?
Ouch! You might try soaking it in 100% virgin olive oil and use a Q-Tip to remove the debris. A lengthy soak shouldn't hurt the plaquette. It might take more than one soak. I'll have to admit that this medalist has the longest name I have ever come across. Jules Prosper Joseph Marie Edmond Legastelois He was born in Paris in 1855, and most notably, was a pupil of Louis Oscar Roty.
A day of soaking in extra virgin olive oil and brushing clean with a q-tip seems to have taken the worst of it off, but has keft areas of darkness.
