As some here might remember, I was gifted a rare Ostrogothic follis for Secret Saturnalia. When I first saw it, it seemed to me that the green encrustations were hiding some good surfaces and details underneath and so I had been researching how to remove them. Now though, the overall green color has grown on me somewhat and this, along with of course the possibility of damaging this wonderful coin, has kept me from carrying out cleaning/conservation. So, what does the forum think? And yes, I know: no electrolysis. Plus, I know cleaning can be a touchy subject so just a reminder to keep things civil and polite, thanks.
I hear ya on not wanting to clean that coin because the colors look nice but the thing is that I believe it has BD in some areas. Some of that green looks like paint or hard enamel deposits. I'm working on my own methods as well as what is online. I have a blower and I would finish getting the rest of the dirt off with soft mechanical tools like toothpicks. It's good with sediment but not some dirt types or hard enamels. I use Q-Tips, pin vises, safety pins, toothbrushes no metal types. Then the distilled water treatment. Wash it off first before soaking. I sometimes heat the distilled water up enough where it is hot where you can stand putting you hand in it and let it soak. Hot water also helps break up the dirt. The question remains. I think the coin will get worse later on, but it's hard to say, maybe the coin could stabilize on it's own.
Not sure cleaning will help this one. It is an attractive coin as is. Could try some brushing with a toothbrush which you have shortened the bristles on by cutting them with scissors or wire cutters, which will remove any loose debris. To guard against Bronze Disease/Verdigris, get a bottle of VerdiCare/VerdiChem (Wizard Coin Supply) and treat it.
I see very little from the photo that suggests further 'cleaning' will really help but i'd consider boiling distilled water and a soft toothbrush....
Unless you're confident that there is bronze disease present, I wouldn't touch it. It is likely to cause more harm than good.
Yeah, it looks like someone was not too careful with the high points. Its almost not distracting for me, fortunately. I tested the brighter spots for BD and they are hard, not flakey or powdery, so I'm pretty confident it doesn't have BD.
Just wish whoever had partially cleaned it had worked a little more on the legends and the wolf and twins.
Interesting how we get so many different opinions. I might poke at the un-green area just left of the XL and see if it might come off and reveal green below but only if it looks raised from the surface in hand like it does in the photo. After that the idea of the clipped down tooth brush has appeal but I would not use liquids including water. I am not sure about Verdicare. I would not soak it but a thin layer as a sealant might not hurt if the result is patchy after you do what you will do up to that point. I hope you will post an after photo and tell us what went right and what went wrong.
I would only let a pro try to improve it. Maybe YOC or NGC conservation. I would be afraid to touch it myself. John
Oh yeah, for sure Doug. It was definitely a learning experience cleaning my Tiberius denarius during the summer and I was glad to share all that here with everyone. With this follis, I'm thinking of leaving as is for now, and to try and acquire any cheap ancients that are green encrusted to at least some extent so that I may practice cleaning them. Then perhaps down the road, with any newly acquired knowledge and insight I gain from that I can approach cleaning my follis more confidently (but its very likely I won't clean it anyways since, again, I kind of am liking the shade of green on it and how it doesn't totally cover up all the details).
