PVC Damage?

Hello all, I recently dipped a Meiji Yen I have due to a very unattractive toning & good details, but this is what I discovered underneath it.

Is this some kind of PVC damage? Should sitting it in acetone for a few hours fix it up?

1. Who knows? It could be some other type of corrosion
2. It can't hurt (dipping is far more harsh treatment than acetone).

Hello
I don't think it will remove this rust solvent, I don't think it's PVC coating. Another metal is mixed into silver, it is not pure 999 silver, and the admixture gained rust due to storage, the effect of a chemical reaction from the environment.
I will not write how, get a translator from Czech and you need to change your mind if you do something-You removed the prettiest on the coins here and it's a patina.
Even in your country, there are a lot of works and long articles, as well as hundreds of procedures and opinions:

https://cs.puntomarinero.com/patina-what-is-it-natural/

https://www.twicz.com/novinky/cistit-nebo-necistit-mince-co-radi-numismatik/

https://www.numismatikasova.cz/radce/jak-vycisti-stribro-stribrne-mince-stribrne-mince/

http://www.numismatika.com/?page_id=404

https://www.lovecpokladu.cz/home/cisteni-minci-ala-numismatik-1744

Etc. etc. How many numismatists so many opinions - now I have set a definition!

Ahoj Ivan

it looks fine to me. those are normal silver tarnish tones. you would do more harm than good to remove it.

Every time I see these "NO, NO, NO!" to cleaning coins, I remember restoration and INTENSIVE cleaning of works of art: medieval paintings, frescoes... Only after cleaning these works showed their true beauty and value. Any reason this should be different for coins?!

Verweis : "Mr. Midnight"​it looks fine to me. those are normal silver tarnish tones. you would do more harm than good to remove it.
​

​They aren't, as the e-z-est would have removed them if that were the case.

Verweis : "Dejan"​Every time I see these "NO, NO, NO!" to cleaning coins, I remember restoration and INTENSIVE cleaning of works of art: medieval paintings, frescoes... Only after cleaning these works showed their true beauty and value. Any reason this should be different for coins?!

​Grading services do not consider proper dipping to be cleaning, this is considered restoration.

Did you try electrochemical reduction yet?

Verweis : "tdziemia"​Did you try electrochemical reduction yet?
​

​I wish you a nice Olympic weekend.
My wife bakes cakes so I took some powder for the chemical-electrical reaction. I was also looking for a large coin that may not have been destroyed, so I used a small one but there is little silver and more copper, at least it will be better to see what happens to copper.
I used a damaged and cheap coin for the experiment, Hungary, Ferdinand II, 1624, stamped in Kremnica.
There was really a lot of silver in this mint, and only then did the monarch insist that too, too little silver be put into the coins. ( simply the rulers then and today are the same turnover of us poor people as much as possible)
It's this coin:


coins before and after the experiment:


details (just please primine me, no art photos):
green corrosion before cleaning

after chemical - electrolysis for 10 minutes:
silver is pure and copper is brown-red.
It is necessary to use either preservative oil WD 40 or soak in vegetable oil, but it will catch the patina according to the type of oil.

What I used? instead of lemon I put a little pure citric acid powder (for cakes)
baking powder (soda)
Distilled water, and a drop of dishwashing liquid.

ultrasonic washing machine.

I don't know, but I wouldn't do it with more expensive coins, and I also think it's better than scrubbing with a cloth and brush.
Ivan

Hello
So I immersed the same solution and electro-ultrasound for only two minutes for gentle dry cleaning and applied the WD-40 foil. As an example, please let all numismatic gods forgive me and my Indian friend not get angry.
It's a victim for the show, in a hurry.
https://en.numista.com/forum/topic117049.html
under number 9 is the error , it will be deleted.


Ivan