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Cleaning gold

Is there a good way to clean gold coins that mostly have dirt from handling? None of them are rare, but could benefit from a good cleaning. I've thought about ultrasonic cleaners like for jewelry, but not sure what it would do to them.
Previous transactions: Wondercoin, goldman86, dmarks, Type2
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I'd leave them alone !!!
"a good cleaning" - those words make me shiver when it comes to coins.
BTW - on occasion I have had to clean some common coins for a project and I can tell you that even a mild bath in soap and water will have an impact. Yes, they look "clean", but it is not a natural look.
Acetone will remove organic crud... just do not perform any abrasive action on gold. Cheers, RickO
Without pictures, the best advice will be mostly useless, but a 30 second buzz in water in an ultrasonic for a generic gold coin is no risk. Per @JBK, no detergents.
The advice is different for a 55 or better $5 Indian with European vault dirt than it would be for a $20 Saint in 62
Why would you want to erase the history behind the coin? If it looks like it was used in commerce it most likely was and that adds to the provenance and value in my opinion. Cleaning, no matter how slight, will only be detrimental to the value and the coin. Where dirt has protected the coin would likely look really different than the rest of the coin if cleaned off.
JUST LEAVE IT ALONE....if you want a clean looking one sell yours and buy a cleaned coin. Just don't ruin yours.
bob
So what do the good folks at places like NCS do?
Well, if you are talking cleaning they don't do that. Cleaning is a no no for coins. Lesson number 1: don't clean/polish/mess with your coins. Leave them as is.
NGC and PCGS will conserve a coin (removal of haze, etc but will not clean a coin for you). Conserving can be similar when you think of PVC residue or gas off from plastic on the coin but it is not cleaning.
When you see a haze all over the coin like you can see on many brown box Ikes they will remove that by means that does no harm to the surface of the coin.
INFO: https://www.pcgs.com/restoration
bob
From PCGS: PCGS Restoration will remove contaminants that are determined to have been deliberately and artificially applied, including putty, grease and other substances used by "coin doctors." Restoration also will remove contaminants on the coin's surface caused by improper care or storage, such as polyvinyl chloride (PVC) or verdigris. Recent fingerprints also can be removed.
I have had good luck with having bondo removed by the tpgs if the coin is certified; and acetone, etc. for removing pvc. "Dirt" removal can change an ms coin into an au without real recourse.
I've used MS70 on some xf British Gold Sovereigns and I think they were improved. These were "bullion only" coins. OTOH, I would have to give it a bit more critical thought before treating an "obviously collectable" gold coin the same way.
Generic US gold - hey, they are your coins and if they are crumby-looking, generic, run-of-the-mill coins, where's the problem from cleaning? If they turn out looking "cleaned" then it wasn't a good move.
Otherwise - again, they are your coins. If someone else thinks they are collectable and worth a premium, put them on BST and see if anyone wants to put money on it by paying you a premium.
I knew it would happen.
I'm buryng them in old coffee cans to get that Saddle Ridge look.
``https://ebay.us/m/KxolR5
Have some fairly generic quarter and half eagles with the same distracting "gunk" in the crevices of the design. I assume it comes from a bad clean job from a previous owner. Is it worth cleaning in anyone's opinion and what may be the best way to help them? I wouldn't call this circulation dirt or grime... thinking this may be a time where some minor cleaning could be warranted.
Acetone
I believe that would do the trick!
For sure...that is PVC.
I'm pretty sure gold does not get pvc damage. I've used a soft wooden toothpick to pick out grime like this without any negative side effects.
I’ve cracked out MS saints and Indian eagles then gave them an acetone dip. I liked the results a lot on the Indian eagles but I thought there was some loss of the classic patina on the saints. Use caution and don’t scrub them ever!
BECAUSE DIRTY COINS ARE LESS ATTRACTIVE. For example, I hate to see an incuse Indian with black crud in the recesses that can be easily removed yet not change the "skin" or color of the coin AT ALL! A $5 bill plus some time under the microscope is well worth it. A good cleaning job is called "conservation."
While gold does not get damaged, it does get a coating of film or lumps of green crud in the recesses.
On a circulated coin as this, Acetone will remove it quickly. If the coin were an original Uncirculated piece, there are proprietary options that someone besides me is apt to reveal.
you can "clean" Gold with most anything as long as you're not touching it with anything or trying to abrade the surface in any way. as with all coins and all contaminants it's best to figure out what it is before attempting to remove it. knowing what you're removing will tell you how to remove it.
this does look like PVC, so acetone will work. you can also use something like E-Z-Est to remove haze and give the coin an even appearance without affecting it in any way.
Thanks for the responses. Sorry I've been away for a couple days. Actually the picture is much more "washed out" looking than the coin itself. Color is much better in person... was just curious what the crud was from. I generally won't touch any coin but these are not high grade and actually paid bullion price. Spots are real distracting, planning on trying one or two this weekend.
Never clean a coin, you might accidentally wipe off hundreds of dollars. If you think there is a problem send it off to conservation at a 3rd party grading company.
PVC gunk.
Try acetone.
Try Dichloromethane. Best thing for pvc. Wet a Q-tip and gently roll it over it.