Conservation Tips?

I picked this up years ago when I was a young collector and didn't quite know good coins from bad. I like it, still has quite a bit of detail. But as you can see it's covered in black gunk and has had some cleaning done to it in the past. Any tips? Leave it as is? Acetone?

 

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I'd start with distilled water, keeping it covered to avoid too much in the way of airborne particulates getting in. If a couple of days of that doesn't work, up it to acetone, and if that doesn't work, up it to xylene. If that doesn't work, or, at any point, you decide you've put too much effort into the coin, give up.

 

It's certainly worth soaking, as @Paul M. suggests. You won't hurt the coin, at least.

 

Looks like old tar to me. If it is, good vodka and a cotton tip is a gentle cure. 8/r4cv <this last comment by Tigger a 7 week kitten>

 

True True. Didn't even think of the distilled water.

 

I'd avoid any kind of swabbing. You can soak in acetone or xylene almost indefinitely. With respect to coin metals, they're practically inert. I'd keep it in a dark place, too, if possible, just to avoid any photochemical reactions.

 

I was thinking the same thing, but couldn't be sure from the photos. Surely it would be better to try the water/acetone/xylene soaks before any attempt at dipping, though, right?

 

I agree. Looks just like terminal black toning. It looks like the previous cleaning removed some, and the metal underneath was already starting to corrode. Look at the fields on the obverse, it looks like toning pitting. To save the coin you have to have someone dip it, and even then I am guessing it will all be lightly corroded underneath.

This is what happens when the "pretty" toning continues to react. Keep your coins as white as possible people, and prevent toning so more coins like this in the future don't happen.

 

Yea I noticed the corrosion and that's why I wanted to get the black off to stop if from happening more. I've had this coin for years and it's always been like this. Where's the best place to get it dipped? (I have not the skills or knowledge to even attempt to dip it). I'm also going to try the water and acetone first. Just to see.

 

Well, the toning people have vilified people who dip coins for so long its probably harder to find one today. I would start with a good local dealer if you know one.

 

If the black stuff isn't crud, I don't think you're likely to like the way it turns out. I'd only dip it for the experience, without expecting any kind of good result.

 

Good point. So lets say that water and acetone don't work. If I don't dip it and leave it the same what would happen? Would the corrosion get worst? Or would the coin remain about at the same level it is now?

 

If the reaction is allowed to continue, it will eventually eat away your coin until only black silver oxide is left. Stored in proper conditions it should stop, but active toning, (corrosion), always is a danger. That is why badly toned coins should be dipped, to stop the potential to go further.

 

Of course you will probably be dead by that time, even if you are a young numistmatist.

 

What would be the best thing to use for dipping?

 

Some people like Ranch, some like French Onion...OK, sorry, the devil made me do that. Dipping for silver is usually done with a mixture of sulfuric acid and thiourea. If that sounds like too much, it is available as eZest from e-bay or any coin supply.

 

For that coin you might want to pre-treat the front with some eZest on a cotton swab applied just to the affected areas and watch to prevent overdip (be ready to rinse the material off with running water).
Then try dipping the whole thing.

 

Maybe, but OTOH I have seen serious corrosion on 5 year old ASE stored badly.