Experiment with Verdigone (tm) on copper cents

Thad,

Ever considered developing something for pure nickel, and AL3 coins?

 

Log in or Sign up to hide this ad.

Spock- I don't think it will come back at all if you coat the coin with Blue Ribbon or mineral oil. Mineral oil soak will cause the verdigris to become cut-off from from air and moisture. The second step is low humidity proper storage environment (IS or air-tite in zip lock bags with air sucked out). I don't leave Blue Ribbon on the coins ususally secondary to microfiber hairs won't come out as it is too sticky. I remove with acetone. In fact, I guarantee you I could get it off with a rose thorn after a long soak in mineral oil and you would never know anything was there except slightly removed outer layer of copper secondary to possible underlying damage from the verdigris in the first place.

 

i agree with you Boss but i cant coat oil on my modern coins. thats a no no. i have everything in airtites with dehumidifiers and in IS so storage cant get better. i might be tempted to use your method on some nickel coins that are in danger of being lost to humanity

 

Yes, but lab time is seriously in short supply for me. It's on my wish list!

 

I've never experienced that, but I only use ACS, reagent grade acetone. I only use acetone for drying, I prefer xylene for removing surface debris.

I respectfully disagree, it's all according to the degree of the problem. If done correctly, some problems can be "repaired" with no negative effects. Of course, NCS does this routinely.

That is FACT. The problem is two-fold: 1) most people do not possess the scientific knowledge to approach the problem correctly 2) the common commercial products are FAR TOO HARSH and contain ingredients that damage the metal surface permanently.

Absolultely, verdigris actually REMOVES metal from the surface as it forms the cupric compounds. Copper ions are physically pulled away. However, if the verdigris is not deep, i.e. "pitted in", it can be removed with virtually no trace and no noticable surface damage. It's all about serverity and also type (acetate, chloride, sulfate or carbonate), each one of them has a different degree of difficulty when it comes to removal.

Case in point, my 1909-S VDB which had very light, early stage verdigris. I was able to remove the verdigris with VERDI-GONE™ and pass the NGC grading process. If there was a detectable problem, they would not have graded the coin.....so verdigris CAN be safely removed in some cases.

Indeed again, these products are all EXTREMELY HARSH! IMO, they will do more damage than good!

 

well if you do let me know. i have an extensive collection of nickel coins that need help from the time of the british raj in india.

 

Agreed. Verdigris can be safely removed from a lot of coins i have had great luck removing it on 100+ coins with biox no problems. silver is the easiest to work with while nickel and al3 are the worst. although the verdigris has never created a pit in either al3 or in silver in nickel it has created nothing but pits. copper and copper nickel is all pot luck. what i am worried about it is how on earth did verdigris get on coins that are ina dehuidifed enviornment and in airtite conatiners or IS containers and why only indian coins and no usa coins?

 

No answer to that one. I know verdigris can spread from coin to coin. Can't explain how verdigris started on a coin in an airtight container in a dehumidified environment.

You're becoming the coin restoration expert spock. Maybe I should send you my problem coins.

 

7 day results:





I think I will continue the experiment one more day and then take both coins out, dry them, and let them sit in the air for a week and see what the end effect on the patina is. I am glad that Thad is on board and can comment or answer any questions. Thanks for sticking with me. Science can be interesting and somewhat boring at the same time :rolling:

Jim

 

So mineral oil is bad for coins? Not sure of the pH of mineral oil. It can't be as bad as olive oil, or can it? Many people use it, along with coin care and others. Personally I let the coins be. I think mineral oil is in baby oil which they use on baby's bottoms. Can it be that bad for coins?

 

you are more than welcome harry.

 

dear friend i hate to burst your bubble but there is verdi still left on the coin if it doesnt go it will cme back in full force. another idea might be to stop treating the coin after tomorrow and lock it up in ana airtite and see what happens with passage of time as a controlled experiment

 

well it depends ont he definition of the problem also if you repair coins traces will remain for the trained eye to catch. stains are another thing that can be removed via conservation and the coin will grade no problems but then is grading the only objective and what would u say if there was an 1804 dollar and it had a verdi pit for some reason does it diminish its value.

 

Jim - That last bit of verdigris is not going to be removed. I think continuing to use VERDI-GONE™ at this point if futile. This spot will require the stick + VERDI-GONE™ method, physical action is needed. This coin has already been soaked so many hours I fear for the patina.

 

Mineral oil has no pH. You must have water to have pH (negative log of the hydrogen ion concentration). Olive oil has no pH either, but it does have acidity from the organic acids present. One of the reasons I don't much care for olive oil, being a natural product, the acidity can vary greatly.

 

Great thread! Thank you for all of the effort you put into the experiment and in sharing the results.

 

I am glad we have chemist on this site!!. I did a bunch of research last night and started a post (reply) and fell asleep so it's gone. I will start a new post in the near future.. Read a # of chemistry atricles and found mineral oil has a" 0" reactivity rating in the MSDS. It is used to save metallic equipment/gears and copper products in industrial equipment from oxidation and sheering damage. The science behind mineral oil is that oils have covalent bonding (equal attraction for one another) in long polymer carbon chains. Carbon when bonded to other carbon chains is extremely stable. Water and sulfur, chlorine, etc are ionic elements reacting with other ionic compounds and do not react with oils except in high temperature sitauations. Oils coat the coins and protect it from the elements. Yes they attract fine dust, but in a slab or airtite that is irrelevant- if you left the coin in a plastic flip- that's a different story. I don't like Blue Ribbon so far as it is so sticky- I have just played around with it and removed with acetone. Some will argue you trap the junk in the coins by putting on the oil. Yes, of course- they are coated and rendered inert from reacting with air-contaminants. I wil not except "we learned in the 60's that oils were bad"- sorry Doug. Some one needs to tell the old time EACers this because they have got it wrong for a long time. If someone can present an explanation of why oils are "extremely harsh" from a molecluar point of view I am all ears and will humbly accept the facts. I don't believe in authoritarian arguments, though speaking of that Q David Bowers has a very good section on this his book "US Coin Colecting" under the conservation section. I have had coins soaking in oils for years with no ill effects. I have completely removed verdigris and grime with no trace it was there. I am now going to conduct extensive research over the next couple of weeks and then start a post. No anamosity here- to those who disagree. Just a friendly discussion of the science behind your positions for or against.