Let's remove some verdigris, shall we?

Much better picture of the verdigris we are trying to remove.

 

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Ok ran it three cycles in the shot glass within the ultrasonic bath. It did remove the verdigris, but had some unintended consequences. Here are the pics of after using sodium hydroxide to dissolve verdigris.



Obverse looks better huh. No damage to the carbon or more importantly the copper.


This is where things went too far.. That hole appeared where the verdigris was, and exposed this hole. Also it appears that some AT occurred at the upper left leaves. This I am sure is due to the temperature of the water. Somewhere betwern 120 and 140.

I think I'll just buy the aforementioned Verdi-gone for my large cents and I know I'll have to be cateful in exposing holes where the copper oxidized.

All in all not a bad experiment. I learned that although some things that are supposed to work in theory can use some finesse and genuine expertise. Had fun trying though. Good night.

 

Looking forward to SuperDaves results.

 

That is a really impressive performance for VerdiCare.

Acetone is totally safe as long as you are careful about open flames, and you're not made of styrofoam. Basically, don't chug it or huff it, and you'll be fine handling small quantities. There's a reason it's the main component of fingernail polish remover.

I have a rose bush literally outside my door.

 

What Materials on a coin's surface would acetone take care of?

 

I need something for carbon spots. Anything for that? It has to be almost impossible to attain because we are carbon based right. Probably would damage the coin's lustre too and turn it strange colors.

 

I don't have the facilities to work with HYDROCHLORIC acid or aqua regia. I can handle a little Lye (mild strength base) , but when it comes to acids I need a real lab.

 

I've found that, working with large cents, if the vertigris is hard or compacted that you can get it off with a combination of thorns and chemicals. However, once you get the hard stuff off, you will find that there is a hole/pit/depression where the metal has physically corroded into the copper. Many times, when I get the hard green crap, I just leave it like it is, because that is less noticeable than the black hole/pit that it leaves. The soft green oily stuff from pvc comes off easily with acetone.

 

Except on gold.

 

I need to correct my post: carbon spots on copper are black; that's why they call them carbon spots.

The spots on gold that I said were easy to remove are called copper spots.

The person who discovers how to remove them from cents without a trace will end up richer than Midas!

 

First round of work with the Verdi-Care. I shot this quick and dirty, without much attention to "presentation" appearance (the detail pics are merely 100% crops of the first image, which is forced to half-size for posting here):











First takeaway - Verdi-Care works. I did very little mechanical work, a little with hawthorn (every bit as tough and sharp as Bill said), and a little with Q-tips. Half an hour's contact with the stuff, total, and there's nothing left on the coin I'd characterize as "green" any longer. This has isolated the places which do need detailed attention, and that's the next step.

At this point, I don't believe this coin is a candidate for "complete removal." We'll get most of it, and preserve it for the future, but there are a couple places I think the damage is permanent.

 

Someone please PM SuperDave and tell him he needs to keep his day job! Let him know that I will help him out if he takes me off "IGNORE" and PM's me. I have a very big heart and don't wish to see coins mistreated.

VerdiCare is probably a great preservative (I bought a bottle and have used it); however, that coin is not even halfway done. I know, I know, first round; but I cannot wait a month to see the results.

Somewhere on CT, I've read about a much better corrosion remover (used at NCS) that in less than a minute does a better job and gets the coin ready for a final application of VC if you don't choose another common product - Coin Care.

Earlier I posted that the coin was corroded. At this time there is no way to remove the brown spot damage to the surface that remains after the coin was treated.

 

This is true. Would you also agree that the presence of verdigris can accelerate further corrosion, and that removing it can help prevent further damage?

 

I put Coin Care and VerdiCare in the same category...a preservative that is capable of removing (so also a cleaner ) some types of stuff on coins too.

BTW, some forms of oxidation can protect the metal after they form on its surface.

 

Yep. Otherwise, aluminum would be attacked by water.