Is there a safe way to clean coins?
MCguire19701
Posts: 10 ✭
Hello all I am just sending in my first order to PCGS for grading but I had a question about cleaning everyone says to not clean them but just with normal dirt how would I remove that without damaging the value of the coin? I have been using a electric jewelry cleaner to just remove the dirt with just mild dish soap and that seems to be working fine but is there any other way to get the green corrosion off or just leave it as is? Is being dirty going to affect the value on grading?
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Comments
Don't clean them. Your attempts to "improve the grade" are almost certainly going to fail. The coin market is awash in material that has suffered from unsuccessful cleaning attempts.
Post photos here of what you have and get opinions from board members before spending money on slabbing your coins. They may not be worth the cost of slabbing.
The general rule is "Once a coin is struck, there isn't anything you can do to make it better. It only gets damaged and worse from there. Trying to clean or polish it will only further damage the coin."
But there are also people who swear by acetone.
I've not used acetone, so you would need to pick someone's brain about it.
The substantial truth doctrine is an important defense in defamation law that allows individuals to avoid liability if the gist of their statement was true.
As stated, never clean a coin. An acetone soak to get rid of the green stuff will work. Do not try to rub it off or make it look better. Just leave as is with exception to an acetone soak which will not harm the coin and may get the green and loose dirt off. Once soaked in acetone just rinse with fresh acetone.
See this other thread: https://forums.collectors.com/discussion/1103488/please-advise-how-to-conserve-this-1909-s-ihc#latest
bob
What is your objective with the submission?
Cleaning coins or just about any effort to enhance them will not produce TPG results that will be satisfying.
Consider taking a look other threads here that address coins that have been enhanced- if you seek bright white coins that have been stripped of originality, there is an ample supply that have been graded and you can buy those instead of asking about cleaning and being disappointed with the cleaning aftermath.
Experience the World through Numismatics...it's more than you can imagine.
If the coins are extremely valuable dates or types and need restoration, your best option is probably to have the TPG do the analysis and restoration, as they do it all the time and will then grade the coin in most cases. If they are low value coins reconsider submission.
Your open ended question without details or pictures makes it difficult to say anything other than don't clean your coins.
Such a large question with so few actual details.
As such, my advice would be to go ahead and clean them any way you want if you are willing to lose upwards of 90% of their numismatic value. Good luck!
In honor of the memory of Cpl. Michael E. Thompson
What Tom said.
As a general rule, please don’t try to ‘improve’ a coin. It’s just not worth the risk, IMO. Valuable coins are lost each year when well intended efforts go completely off the rails.
Dave
From everything I see below, don't!
Disclaimer: I'm not a dealer, trader, grader, investor or professional numismatist. I'm just a hobbyist. (To protect me but mostly you! 🤣 )
Dish soap can be a horrible mistake with copper.
"Dirt", as in actual, literal, you-can-grow-plants-in-it dirt, should just come off a modern coin with a regular wash in water.
"Dirt" isn't green.
If we're talking about an ancient or mediaeval coin that's been dug up out of the ground, with literal dirt still concreted onto it, this will need to be removed professionally, though again we'd like to see pictures before proceeding, because for certain ancient coins "dirt" (which should be removed) can look an awful lot like "patina" (which should not be removed).
A modern coin with "green stuff" on it is usually a bad sign; it's been corroded by something. Any attempt to remove the corrosion will likely leave a pit or crater on the coin, since the metal that used to be there is now gone, corroded away, the damage is already done and can't be undone.
If the green stuff is sticky, then it's "green goo" from being in contact with PVC or similar plastic containing acidic plasticizers. The green goo can be removed with acetone, but if the goo's been sitting on the coin long enough to turn green, then the damage has likely already been done and acetone will remove the goo but reveal the underlying damage.
If a bronze, brass or copper coin has a pale green, powdery deposit on it, this is a very very bad sign. This is most likely "bronze disease", a contagious form of copper corrosion that not only can slowly spread across a coin's surface, but can jump from coin to coin if little flecks of the powder break off and land on other coins. Bronze disease is often "terminal" in terms of a coin being acceptable by the graders, since it needs to be treated, and any treatment successful at removing the bronze disease will create a "cleaned coin".
I assume an "electronic jewelry cleaner" is an ultrasonic bath. Ultrasonic baths are great in theory, but fail in practice, for two reasons: First, you need soap or detergent in the water for an ultrasonic bath to work properly and soap is often not good for coins, and secondly, ultrasonic baths tend to make coins placed in them rapidly vibrate back and forth. Anything touching the coin - the sides or base of the bath, a plastic holding-rack, or even your fingers - will rapidly rub back and forth on the coin, creating a "rub mark" at the point of contact.
Roman emperor Marcus Aurelius, "Meditations"
Apparently I have been awarded one DPOTD.
I've used soap and water soaking with no bad reactions on coper. Have you has bad results? What happened? Did you rub the coin?
I know for a fact (I asked Mike Fazzari about cleaning coins after his lecture) that he uses one at NCS. Two things he told me must be done. The coin must be moved around in the solution so bubbles don't get trapped on the coin and bore a hole into its surface and nothing should touch the coin - even a plastic basket or tray will eventually cause a rub. He holds the coin with plastic tongs that only touch the edge and not even the coin's rim.
Thanks all
Please show your thanks by providing the missing details that several people have already asked for?
Do both sides of the coin 1-2 hours each side (longer if needed) then like he stated rinse under fresh acetone and put the old acetone in a glass bowl leave outside will evaporate fast then clean the bowl dish soap.
Always use 100% pure acetone. Pharmacies have them for sale.
Acetone use a glass jar with glass lid or full metal lid no inner plastic lining so the acetone does no affect the any plastic material. Mason jars are good.