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Hello!! I need help with this green spots [solved]

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Emiliano01
Joined: 7-Mar-2015
Posts: 107
Hello, some months ago I received a large collection with silver coins, most of them in excellent conditions..

But they were stored in one of those German albums which make green spots!!!

I have already removed them from the pages, but I want to know if although I move them to a capsule, the green spots will grow more??

These are two examples:

This one is not easy to spot, the spots are not very visible
apuking Numista team
Joined: 31-Oct-2012
Posts: 3988
Thats PVC damage.
try to have it removed with Acetone.
Pre 1900 Quality Coins, Medals and Tokens only.
Steve27
Joined: 22-Mar-2016
Posts: 957
In addition to soaking those coins in acetone, I would also soak any other coins which came out of that album as well. In case you're not familiar with using acetone, you need to use a glass jar/container (acetone will dissolve plastic).
Emiliano01
Joined: 7-Mar-2015
Posts: 107
Quote: "Steve27"​In addition to soaking those coins in acetone, I would also soak any other coins which came out of that album as well. In case you're not familiar with using acetone, you need to use a glass jar/container (acetone will dissolve plastic).
​Hello Steve27, first i rubbed of with a cotton rag all i could without damaging the coin, i just have to soak them in acetone? For how many time? The album came with many pre-1950's coins in excelent grade wich are worth some money, copper and silver, will the acetone change the patina or destroy it??

The same has happened to a proof coin, should i treat it the same??

Thank you!!
apuking Numista team
Joined: 31-Oct-2012
Posts: 3988
Acetone should not harm your coins patina
Pre 1900 Quality Coins, Medals and Tokens only.
Emiliano01
Joined: 7-Mar-2015
Posts: 107
Quote: "apuking"​Acetone should not harm your coins patina
​Thank you Apuking, i will try with two cheap coins, it would be a shame to gave them a dark tone for a UNC coin
Steve27
Joined: 22-Mar-2016
Posts: 957
Quote: "Emiliano01"
Quote: "Steve27"​In addition to soaking those coins in acetone, I would also soak any other coins which came out of that album as well. In case you're not familiar with using acetone, you need to use a glass jar/container (acetone will dissolve plastic).
​​Hello Steve27, first i rubbed of with a cotton rag all i could without damaging the coin, i just have to soak them in acetone? For how many time? The album came with many pre-1950's coins in excelent grade wich are worth some money, copper and silver, will the acetone change the patina or destroy it??

​The same has happened to a proof coin, should i treat it the same??

​Thank you!!
​Acetone is safer on coins than water. The biggest problem you may have is damage caused by the PVC, which cannot be fixed.
Dato Mikeladze
Joined: 25-Mar-2014
Posts: 1880
Quote: "Steve27"​In addition to soaking those coins in acetone, I would also soak any other coins which came out of that album as well. In case you're not familiar with using acetone, you need to use a glass jar/container (acetone will dissolve plastic).
​Where your advise was 15 years ago... when I used acetone in plastic jar to clean 1762 Angola 5 macutas... and I killed my coin  :(

thanks god that there are people who are not lazy to give advises.
thanks !
best
D
Numista referee for  Georgia.  Also  for Belgian Congo, Congo free state, Katanga, Kenya, Ruanda-Burundi, Ruanda-Urundi, Seychelles
Emiliano01
Joined: 7-Mar-2015
Posts: 107
Today I will try it on a 1 peso coin 1957 in UNC condition

These are some examples of the coins that will need the acetone treatment (among almost 100 coins)


50 centavos (revolutionary) 1915 Zapatista issue in Morelos KM#703 Numista Rarity Index: 95


5 Pesos (Southeastern Railroad) 1950 KM#466 Numista Rarity Index: 59


1 Peso 1872 KM#408 Numista Rarity Index: 53


1 Onza 1985 (Silver Bullion) KM#494 Numista Rarity Index:25


500 Pesos (Commemorative issue: 75th anniversary of the revolution) 1985 PROOF KM# 511 NRI: 84

I really hope this works, thank you!!!
GSDykes
Joined: 12-Feb-2015
Posts: 8
I agree with the above advice - soak in acetone all of the coins (including proofs). The green seems to be PVC damage, however most of the coins you pictured have some copper mixed in. The green may be corrosion damage via the copper content. If so the acetone may not remove it. Copper may respond to a mild acid (not hydrochloric). I would try using plain old ketchup (a tomato paste). Just soak the coin in ketchup for about 3 minutes and then gently clean. Experiment with a low value coin. But FIRST try the acetone.
Gary in Washington State
Mr. G. S. Dykes
ANA #3179303
WBCC #578
Emiliano01
Joined: 7-Mar-2015
Posts: 107
Quote: "GSDykes"​I agree with the above advice - soak in acetone all of the coins (including proofs). The green seems to be PVC damage, however most of the coins you pictured have some copper mixed in. The green may be corrosion damage via the copper content. If so the acetone may not remove it. Copper may respond to a mild acid (not hydrochloric). I would try using plain old ketchup (a tomato paste). Just soak the coin in ketchup for about 3 minutes and then gently clean. Experiment with a low value coin. But FIRST try the acetone.
​Gary in Washington State
​I will use "Pure acetone" wich i can buy in a drugstore, then damage is not so bad, so i hope no other methods should be used, i once tried the ketchup method with bronze, and results where a pink coin, not very nice to sight, i will update this thread with the results.

Thank you!
Emiliano01
Joined: 7-Mar-2015
Posts: 107
I want to give special thanks yo Steve27 and Apuking, the acettone worked perfectly, only in the copper ones i didnt had antes 100 resultados, but everything went better than expected!!!
Garycrant
Joined: 30-Jan-2017
Posts: 14
Just to add on, make sure that it is 100% pure acetone (2-propanone, or, propan-2-one --> for the Chem people). Also, at the hardware store within probably a one meter radius of the acetone, look for methyl-ethyl-ketone, M-E-K. I prefer the results from that ketone a little better than acetone (M-E-K is also known as 2-butanone, or, butan-2-one). I think if you want a larger ketone, you may have to order it from a lab supply place.
Garycrant
Garycrant
Joined: 30-Jan-2017
Posts: 14
Garycrant
alfred1
Joined: 6-Mar-2017
Posts: 36
a saline wash is also quite good to get rid of verdigris
Garycrant
Joined: 30-Jan-2017
Posts: 14
"...saline wash..."

I haven't experimented with that method. Do you have data to support? Or, should we just look at pics of salvaged shipwreck coins?
Garycrant
Beekeeper
Joined: 9-Dec-2016
Posts: 133
Quote: "Garycrant"​"...saline wash..."

​I haven't experimented with that method. Do you have data to support? Or, should we just look at pics of salvaged shipwreck coins?
​The shipwreck coins would be misleading. When barnacles and coral start growing on your coins it would be considered more like a soak than a wash. The saline solution in an ultrasonic cleaner would be better at washing than throwing your coins in the ocean.
Garycrant
Joined: 30-Jan-2017
Posts: 14
Quote: "Beekeeper"
Quote: "Garycrant"​"...saline wash..."
​​
​​I haven't experimented with that method. Do you have data to support? Or, should we just look at pics of salvaged shipwreck coins?
​​The shipwreck coins would be misleading. When barnacles and coral start growing on your coins it would be considered more like a soak than a wash. The saline solution in an ultrasonic cleaner would be better at washing than throwing your coins in the ocean.
​ Beekeeper, thank you for posting and spreading the knowledge my way! I have just heard 'whispers in the wind' and read several nebulous posts over the past few years about using saline on verdigris. But that is where the information would stop. The other part that I haven't tried or heard is to use an ultrasonic cleaner along with the saline, correct? Such as an ultrasonic cleaner that most jewelry stores have? Sorry for this barrage of questions, but it seems like you're the person with the answers. What is your saline solution? Is NaCl the salt you use? And is it disassociated in distilled, D.I., or tap water? Also, how strong is it - as in molarity, w/w, w/v, standard medical 0.9% saline sol't (9g NaCl/1 L water), or just fully saturated at STP, etc.? Then, 'wash' vs. 'bath' or 'soak' with respect to time - is it on a scale of seconds, minutes, hours, or just keep an eye on it and it's done when it looks done?
If all that is too much, I understand. I am not trying to be rude or overwhelming (most likely underwhelming), I just want to learn. This is my main hobby, I picked it up a few years ago during a rough time in life and it got me through. And I still love numismatry because...all of it! I view this as just one branch of the hobby/discipline, this 'branch' being conservation and preservation of my collections. Anyways, thanks in advance for your time knowledge and be well.
Garycrant
Beekeeper
Joined: 9-Dec-2016
Posts: 133
The knowledge I was trying to pass on to you was that salvaged shipwrecked coins were pictures NOT to look at.
As far as the rest of your questions, I don't know. I just started experimenting with this myself with 1 spoon of table salt and tap water in the cleaner and some green copper coins to find out for myself. Will try TSP after if this doesn't work.The ultrasonic cleaner I have is; https://www.amazon.ca/gp/product/B001DKDAVW/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1 .
Garycrant
Joined: 30-Jan-2017
Posts: 14
Quote: "Beekeeper"​The knowledge I was trying to pass on to you was that salvaged shipwrecked coins were pictures NOT to look at.
​As far as the rest of your questions, I don't know. I just started experimenting with this myself with 1 spoon of table salt and tap water in the cleaner and some green copper coins to find out for myself. Will try TSP after if this doesn't work.The ultrasonic cleaner I have is; https://www.amazon.ca/gp/product/B001DKDAVW/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1 .
​Yeah, I gotcha. I keep forgetting that words are the only thing we were using to communicate with, the expression on my face would have let you know that I wrote that in jest. Shipwreck stuff are novelty items for tourists. The gold will still be there centuries later, and history for the ocean archeologists to sort out. I've done some goofing around with chems and coins made from almost any element used in coinage and a pretty wide array (ratios, purities, etc.) of all the alloys that can be made from those elements, even the clad and "sandwich" base-metal fiat coins like the U.S. and Panama. I just always wondered about the saline/verdigris. The key to it is the ultrasonic cleaner. I went ahead and put together my own solution for verdigris that seems to do the trick; the coppers, nickels, brasses, bronzes, silvers, irons, and WWII zincs still look nice and fresh after 2 years and almost a month. Have you tried anything other than saline in the ultrasonic cleaner yet? I just had a memory flash of a store near me that has one of those cleaners as part of their business and I'm pretty sure they haven't used on a coin...yet. I wouldn't want to mess up their machine experimenting. Have you tried distilled water or a weak buffer solution? I think the frequency of the 'ultrasonic' cleaner might be what really does all the heavy lifting and the saline just acts as a medium to carry the particles away after the high frequency sound (pressure) waves literally rattle and shake the verdigris off particle by particle. Does that make sense to you?
Garycrant

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