Conserving coins with acetone before storing 1 1

[CoffeeTime]

I’m interested in the best tips and tricks to using acetone to conserve coins before adding them to the collection.  What does your flow look like?
 

quick background.  I’m fairly new to collecting and I’m becoming very interested with my sons growing interest.  He is still in the “fill the penny / nickel book” phase and loving it. Some of the coins we find in rolls are fairly nice. I’d like to converse the nicer ones (AU+) before putting them in 2x2s while he gets the others for his book.  Basically, I want to get any finger oils off the coins before storing. That said, I have been reading everything I can on the hobby as I’m interested in starting a few sets myself.  

[Oldhoopster]

If there is no visible signs of PVC plasticizer residue or other asst crud, I just soak for 1-2 min.  Check the acetone for cleanliness by putting a couple of drops of a piece of glass.  If there is a dried residue, change the acetone.  If you keep the acetone clean, you really don't need to rinse

If you want to be extra safe, use 2 containers of acetone.  One for the initial soak and one for a rinse.

Edited August 7, 2022 by Oldhoopster

[EagleRJO]

The following are articles from NGC and PCGS about cleaning coins, with the NGC article making a vague reference to acetone for fingerprints, and with the PCGS article specifically mentioning acetone.  I am a newer collector, but my understanding is that submerging a coin in acetone to remove loose grime and fingerprints is okay, [edit] and NO NOT RUB OR WIPE a coin even to dry it.  That can move dislodged particles around the surfaces causing scratches.

Fingerprints And Conservation | NGC (ngccoin.com)

Detecting Doctored Coins, Part 1 (pcgs.com)

I got a kick out of the quote in the PCGS article about an astute numismatist who said: "All coins are doctored ... It's just a matter of degree and by whom, Mother Nature or Joe Dipper." 

Edited August 7, 2022 by EagleRJO

[Oldhoopster]

On 8/6/2022 at 9:32 PM, EagleRJO said:

The following are articles from NGC and PCGS about cleaning coins, with the NGC article making a vague reference to acetone for fingerprints, and with the PCGS article specifically mentioning acetone.  I am a newer collector, but my understanding is that submerging a coin in acetone to remove loose grime and fingerprints it okay, but it is an acid, so it needs to be rinsed with clean/distilled water (unless its copper), and NO NOT RUB OR WIPE a coin even to dry it.  That can move dislodged particles around the surfaces causing scratches.

Fingerprints And Conservation | NGC (ngccoin.com)

Detecting Doctored Coins, Part 1 (pcgs.com)

I got a kick out of the quote in the PCGS article about an astute numismatist who said: "All coins are doctored ... It's just a matter of degree and by whom, Mother Nature or Joe Dipper." 

You said

but it is an acid, so it needs to be rinsed with clean/distilled water (unless its copper)

Acetone is a solvent that won't react with metals or toning on coins.  Most/all will evaporate before you even get a chance to rinse in distilled water.  The only reason to rinse is if you use dirty acetone and it won't matter unless you are very, very quick.  A distilled water rinse doesn't hurt but it really doesn't help anything

Been using acetone for years and Freon before that, and have had no issues with not rinsing. But I usually do a double rinse and change it frequently.  

A little overkill for removing PVC plasticizer residue

 

[Sandon]

   It's important to remember that acetone is highly flammable, so don't use it anywhere near a flame or something very hot!  It's also unwise to breathe its fumes.

[VKurtB]

But acetone is NOT an acid. 

[EagleRJO]

You guys are correct that it's not acidic, I was thinking of the oil on ur fingers and @Oldhoopster that is quite the supply of acetone! 

Edited August 7, 2022 by EagleRJO

[CoffeeTime]

Thanks everyone, it sounds like the process flow is that easy   

@Oldhoopster  I like the two bowl method.  Im planning to buy standard hardware store grade acetone, and I will do the drying test.  I’m curious, where do you get the lab quality acetone?
 

 

[Oldhoopster]

Hardware acetone works fine.  Mine is definitely overkill.  Just be aware of the following:

* acetone is very flammable and evaporates quickly. Use in a well ventilated area

* acetone well react with many types of plastic.  Use glass jars with metal lids

* don't dump it down the drain if you have plastic pipes

* acetone can damage countertops.

 

[EagleRJO]

On 8/7/2022 at 6:42 AM, CoffeeTime said:

Im planning to buy standard hardware store grade acetone, and I will do the drying test.  I’m curious, where do you get the lab quality acetone?

Acetone that is ACS Grade is readily available on say Amazon which is where I got some pictured below. 

[USAuPzlBxBob]

Fascinating reading about acetone, here.  Takes me back to my R&D laboratory days.

The acetone would get transferred from the Fisher bottle to smaller polypropylene "squirt bottles," and maybe deionized water would be added to drop its flammability down.  The large bottles of reagent grade acetone would immediately go back to the flammable storage cabinet.  It was the way things were done.

This then brings up the question of how grime is removed from within the letters on coins, when conservation practices are used on coins by the the "big" grading companies.

Do they just perform acetone soaks of varying lengths of time, based on degree of grime-removal difficulty?  Or are shaker tables used?  Maybe impinging "squirt bottle" techniques?  Higher temperature?

All of the above?

Anyone know?

[VKurtB]

Please heed this: there is ABSOLUTELY NOTHING that is appropriate for all coins - NOTHING!!!!! Every coin is unique, even before it spends a lot of time with humans, and every coin must be examined and treated uniquely. There is no standard anything. 

[USAuPzlBxBob]

With my questions, the coin I had conserved by NGC had to be submitted twice to them, since the first time they only removed an unattractive fiber within the holder.  It was an 1849-D Gold Dollar, and when it came back the second time there was no longer grime in the "D," nor grime in some of the lettering near the reverse rim.

Also, the coin upgraded from AU 58 to AU 58+ most likely because of its improved appearance.

One thing I liked about submitting it for conservation was that it's a very small coin, and really just needed overall eye appeal, especially when placed anew in an NGC Scratch-Resistant EdgeView Holder.

[EagleRJO]

On 8/7/2022 at 1:01 PM, USAuPzlBxBob said:

The large bottles of reagent grade acetone would immediately go back to the flammable storage cabinet.

Sounds about right with all those "Danger" and "Flammable" warnings and symbols on the bottles.