Arresting corrosion on copper?

if Tommy says it works, I buy, let me check it out

 

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Does Verdi care work for bronze disease on ancients?

 

I can't speak to Ancients but this bronze medal was in pretty bad shape before I used Verdi-Care on it.

 

The Jackson guy strikes again. I grew up there. I have that medal with the ribbon still attached. My great grandfather got it.

 

This medal was available in three sizes. A 3" shown above, 1 1/2" pocket piece, and a 1 1/2" on a thin planchet with a suspension loop for the ribbon. I have pics somewhere of the three I own. In 1929 the3" was priced at $2.00 and the 1 1/2" sizes were $ .50.

The Centennial committee presented each child born in the County during 1929 one of the ribbon hung medals.

 

Personally, I endorse the return of lacquer as a coin preservative.

 

@GDJMSP - A little side note thread regarding verdigris/corrosion/conservation experience I had with a TPG that you might find interesting, if you haven't already seen it. It reinforces what you were saying to the OP.

https://www.cointalk.com/threads/ngc-customer-service.277199/

 

I think you mean shellac which is the 'lacquer' of old, before they started adding extra polymers such as acrylic plastics. Shellac can be removed, but once the acrylic type has hardened, it is almost impossible to remove, even with mixtures of solvents. Since most is used in wood finishing, which can be physically removed, they don't distinguish them by labels.

 

Yes, this, and thank you for mentioning it. Old-style lacquer straight from the insect is still available but most usually referred to as "shellac," while most of what's called "lacquer" today is acrylic lacquer, requiring careful ingredient research on the part of the user.

 

With lacquer, if you don't have an absolutely pristine surface, its protection is minimal. I've seen lacquered metals tarnish.

 

Uh...almost. If all we have is copper (Cu), air (O2 + N2) and water (H2O), the only thing we could form is some oxide of copper. To get verdigris you have to have more. Copper carbonate, copper chloride and/or copper acetate is what is normally considered verdigris. Perhaps @BadThad will grace us with his presents (intended).

 

That's interesting. That may be where it's from then. One grandparent may have been born in 1929.

 

You're right; that's why we occasionally see plainly-lacquered (contemporary to production) copper which has deteriorated all the same. It's just like anything else you intend to paint - surface preparation is key. *


* Do not construe this as a suggestion that you use TSP on a coin.

 

Question? It may be my computer screen but I see something that does not look conserved between the rim and the "E" in the "after" photo!

Tell me it's not there and the coin is pristine again!

IMO, you better send that puppy back to them if you still have it.

 

I do still have the coin.

It's not your computer. There is still slight corrosion there. You must have missed my text written between the first and second set of photos. They tried to fix it but they couldn't totally eliminate the verdigris/corrosion. It's much much better though.

I did like that older slab but now I have a much better coin. I just hope whatever it is they did, it lasts! That verdigris/corrosion obviously most have started after it was slabbed.

 

yes I agree, but I remember soaking model t screwjacks in diesel

 

Perhaps by one of those excellent storage methods you have suggested?

 

Given my propensity to overthink things, I try not to even think about that, living in a (relatively, for America) old city.