What's the best way to clean coins

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Thank you, everyone I have met here has been very help full and friendly, I'll be back.

 

Cool!! I'll look into this! The basic advice gives me a start!

 

Remember that not all 1942 nickels are silver, but the silver ones do have the mint mark above the dome.

 

Pure acetone is a pH7 same as pure water/distilled water. Tolulene [Bmim][BF4] (3.16 to 4.63)and [Bmim][PF6] (5.57 to 7.55)
With tolulene, you need to be sure of the formula for the right composition for the pH range (stay away from [BF4] but even then it's temperature dependent to maintain pH so results can vary considerably compared to acetone which is a stable pH7 at any temp and will just rapidly evaporate/vaporize as the downside in higher temps.

6.5 -7.5 isn't a big deal in my opinion below 6 and above 8 is getting either acidic or alkaline and starts to get sketchy when it comes to reactions with metals.

But I'm not a chemist or scientist, just a hobbyist. Someone that is and knows this stuff better than me with more experience I'm Sure can punch a hole or two in what I wrote or explain it better.

And yes as someone pointed out water is also a solvent. Water is the solvent, salt is the solute when dissolved in the water.. salt water is the solution. So yes it's a solvent that can dissolve solids. Same goes with "hard" or "soft" water. The dissolved solids in the water alter the pH of the water up or down. Which is why tap water could be bad or using the same pure water or acetone over and over could be bad as it picks up more dissolved solids.

 

Yes I'd say "never rub coins" I just don't feel that way about circulation coins that are not in Mint State or even AU that have seen a ton of rubbing already from circulation. Another rub or two isn't going to hurt anything in my opinion.

And I know people are going to say "any rubbing does damage".... OK fair enough.

Kenny Rogers might of said it best "you got to know when to hold em, know when to fold em, know when to walk away, know when to run."

The only way people figure things out and know what they are doing is through trial and error. I think everyone has a story about cleaning or conserving a coin that went sideways on them. Some of them expensive lessons to learn some practiced forever on common coins of little value to learn.
Reality is people are cleaning and conserving coins a lot and damaged coins happen on occasion from it but the more you know about how and what to do the less it happens.

 

Are you sure the coin owner wanted a bright coin or wanted to get rid of the finger prints and the terminal toning above Ms. Liberty’s crown?

 

pH is a property uniquely connected to water and water solutions. I have no idea what your references are to. Some dissolved solids do affect the pH of water and some don't. I am a fan of using tap water to soak/clean coins, but it should be followed by a distilled/deionized water rinse and a pat/blot with a towel.

 

Agree, as I said, I was being picky

 

Hmmm. Well yes. You are quite the stickler to thw details. Lol.
The pH scale is used to rank solutions in terms of how acidic or how alkali they are. ... This pH value of 7 is important because it indicates a neutral solution. All other substances are compared to this neutral point. Any solution that has a pH of less than 7 is considered acidic, and anything above a pH of 7 is a base (alkali).

Knowing this, pH only has meaning in an aqueous solution (in water). Many chemicals, including liquids, do not have pH values. If there's no water, there's no pH.

But in some chemical contexts, there is a hypothetical pH that exists as a requisite for equilibrium. Like concrete for example a liquid that becomes a solid but it has a pH value. You wouldn't want to soak your feet in concrete for an hour, your feet with split and toenails will fall off its a pH 13 alkali.

pH is more of a measure of free ions in an aqueous solution, not necessarily water but water is a necessary component as the solvent of the solution. Even pure liquid form acetone has water in it. I think if you purchased dry form acetone it would be free of water, but... not sure if it would function as a solvent in that form. I've no experience with that to say for sure.

Again I'm not a chemist or anything like that, just a hobbyist with interests. I could be way off base, I've no formal training.
Water is a solvent, acetone is a solvent, there are other solvents. pH is a measure of a solution. Perhaps I have it wrong.

 

So, I thought I'd see what a cleaning could do for a copper coin with verdigris. I grabbed a coin from the pound of coins I got from Littleton that had issues. I tried soaking it in olive oil for 3 days with minor effect.

Here's a pic after olive oil. I don't have a pre-shot unfortunately, but with the olive oil soak and some light work with a cotton swab, significant verdigris was removed. You'll see the remainder stuck around the relief elements.

However, the dark toning over "GEORGE VI" was where I did a no-no:

I did what we're told not to do and really scrubbed at some of the verdigris with a cotton swab after the oil, leaving the black toning behind. I sort of considered this my experiment coin anyway (honestly, I was frustrated after 4 days of oil with minor effect).

I didn't want to take that approach with the rest of the rot, so I moved on to testing with a dip I ordered off of Amazon. The results were... interesting.

This is the coin after one 15 second dip and rinse:



It still had some verdigris on the reverse, so I gave it one more 15 second dip:


Verdigris is pretty much gone, just some toning left behind on those spots. Of course the coin is zorched: toning stripped and the metal pock-marked. I'm not sure how much of the pock-marking was already there from wear and rot, but I'm sure the dip didn't help any. However, the verdigris seems removed - my goal achieved.

One of these days I'll figure how to treat verdigris without too much collateral damage to the coin. Maybe I'll stay with the olive oil for a few weeks next time or move to mineral oil. There may be a trail of burnt copper coins in my wake, though...

To those gasping right now my justification was that I didn't want to leave the rot in place and eventually lose the coin - plus I did want to see the results.

Anyway, just thought it would be an interesting FYI to show what a harsh cleaning did to my copper cent.

 

Without experimentation and trial and error there'd be no progress. I know nothing about that coin, but if it were basically 'pocket change', using it as your sacrificial lamb was worth the loss.

 

oops

 

Don't mean to pick on you, but I am (well....retired now) a chemist. pH is meaningful in water. Concrete is not a liquid any more than oatmeal is. Most solvents that have any solubility in water will actually pull water out of the air. 100% acetone would only last till you opened the bottle unless you used a dry box.

 

That's not fingerprints that is how many 1921 peace dollars tone with an often motted toning pattern, toning above the crown is very pleasing and that could would be welcomed in any serious toned registry set (think sunset collection).

And how i know? ...I was the buyer and after finding out the listing photo and PCGS photo was completely different I contacted them to cancel the sale.

Reasons for PCGS taking a nice toned coin and turning it into a duller coin(that should have lost a grading point) was informed to me by seller as exactly repeated in my prior post.

 

Cool, the 80's I think was when those were popular. You're mama's so fat, she's got her own zip code.

 

The 70's

You're so ugly, when you were born the doctor slapped your momma.

 

Ok, I thought it was the 80's. In the 70's I remember the "in your ear with a can a bear" or "up your nose with a rubber hose" etc. one liners. I really don't remember who started those but I think it may have been Lenny & Squiggy on Lavern & Shirley. Because I vaguely remember an episode where I think the lines were used in the dialog.

I just googled it. It was on Welcome Back Kotter in 1976. I was close, same era as Lavern & Shirley.

 

Your Mama's so sweaty the Navy uses her to Swab the Decks.

 

Yo Mama so big when she lays around the house, she lays AROUND the house...