OPINIONS: If I treat a copper coin by removing PCV..

canadacolornut

Does PCGS considered it "preserved" or "cleaned"?

A serious question because I just did that to a copper penney with MS 70 and when the
sludge was removed it revealed gorgeous toning underneath.

I believe that what I did was consistent with preservation techniques used by NGC since
there are no acidics in the solution, just a power cleaner that doesn't affect the coin
surfaces or the toning of the coin as, say, acetone or EZ Zest does. Think Palmolive
liquid on steroids.

What I think is that I'm going to get the coin back in a body bad with either "cleaned"
or "questionable toning" in comments.

I'm going to send it in anyway but wondering how anybody feels about it.

Thanks......

OchoReales

Never had a problem in the past when conserving a coin. After 35 years as a collector, I learned on cheap coins and haven't had a coin come back yet as 'cleaned' (this, since 1996). Wishing you the best!

1jester

I commend you for wanting to preserve/conserve the coin. In my experience, MS70 alters the color of copper/brass/bronze coins and totally destroys the Nordic Gold alloy. Could you show us before and after pics of the coin in question? Also, acetone doesn't change the color or toning of coins, in my experience.

canadacolornut

Thanks guys. I really appreciate your comments.

I totally agree on brass; tried it and the coin is gorgeous. But there's no doubt that the surfaces have been affected.

That may well be true on the copper, but I'm giving it a shot anyway since the coin was absolutely worthless as it was.

I should have taken "before" pictures, but failed to do so. But I can tell you that the residue was so obvious, and so thick,
that you could hardly have seen the details of the portrait, let alone the surfaces of the fields.

These coins were in a non inert plastic pack for almost sixty years- so you can probably visualize what they looked like.

If MS 70 only removed the contamination, then the toning is consistent with what I believe that copper does naturally
over years as it picks up sulfur and other oxydizing agents from the surrounding environment.

If not-and that may well be the case-then the MS 70 did indeed alter the surfaces and the colors.

I've tried acetone, and don't agree that it doesn't affect toning by the way.

If you aren't careful, it will remove nice toning along with any other discolorants-positive or negative-from the surface of the coin.

All that said, I sincerely wish that PCGS would get into the "conservation" field as NGC has. I think the system addresses
a serious problem in the preservation of endemically natural surfaces that are adversely affected by contaminants such
as plasticized flips and wrappers that the coins have been stored in.

All that said I'm pretty certain that I'm on a Kamikaze mission in submitting the coppers.

And you've pretty well convinced me that the brass threepence will no doubt evoke:

"WE will,WE will BAG you!!..ump ump .."WE will, WE will BAG you!!" from the graders.....

syl

MS70 works well on AU or above coins with good luster, but will affect bronze that has lost its life if exposed too much. Acetone, if used moderately and carefully, will not harm bronze cents .. it will change the color of them if you leave it in a bath though. Mild ivory liquid soap and water, used carefully and gently, works wonders with the "Vicky crud". Nothing but acetone will remove the soft green slime of the beginnings of PVC contamination. Genltely and moderation are the keys.

Lancastercoin

There are plenty of other solvents that will remove PVC residue, it's just that they aren't available at the hardware store. Predicting the color of copper after removal of surface contaminants is extremely tricky with either surfactants or solvents. I can personally attest that both acetone and MS70 will drastically alter color on occasion. I've often had it happen as OP described, with color appearing after residue removal, so much so that I can't honestly say if the color was produced or revealed. But with MS70 I lean towards it being produced by the surfactant reacting with the copper.

As far as being consistent with NCS, they most definitely do use acids (and bases) when warranted. Any soap, detergent, or surfactant of any kind (MS70 included) is mildly to strongly basic, which often affects copper color even more than acid does. It shouldn't come back "cleaned" unless you really got on it with a q-tip, but getting color to holder with a number can really be a crapshoot (which given your dual love of color and certification you probably know from experience even better than I do).

OzzyAndy

"There are plenty of other solvents that will remove PVC residue, it's just that they aren't available at the hardware store."

Any chance you could share what some of these are, I've had similar problems. Have access to the school science order book so should be able to get my hands on many different solvents.

Thanks,
Andrew

sinin1

If you are sure you started with PVC, I would wager you still have it but at a much lower level


acetone does not affect metal structure if short term exposure


I am not sure why it would take off color unless color was in PVC or applied somehow


I have had the other problem with some toned Jefferson nickels - the MS70 occasionally takes off the color

Lancastercoin

<< <i>"There are plenty of other solvents that will remove PVC residue, it's just that they aren't available at the hardware store."

Any chance you could share what some of these are, I've had similar problems. Have access to the school science order book so should be able to get my hands on many different solvents.

Thanks,
Andrew >>



Are you a trained chemist with access to a fume hood? If so pm me.

canadacolornut

Aaron do you have a website or Ebay store? Where can I get your lists?

Thanks

wybrit

Are you a trained chemist with access to a fume hood? If so pm me.

Sounds pretty serious. HCl? H2SO4? Benzene?

Tip of the day for the aspiring chemists among you: "Always Add Acid"