Cleaning Coins with Pencil Eraser!

Another big problem with harsh cleaning is if the coin is liking in detail, its possible to removed the last remaining details for even being able to identifying the coin.

 

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Hey, welcome to CT. There are erasers and erasers...the usual one found on the end of a pencil (old-time spell-check ) will usually damage a coin. Some "gum" erasers have been mentioned by posters here as being less prone to cause damage. You would only notice any "damage" if you rotate the coin around under a point-source light while looking for parallel light scratches. Nonetheless, as you say, if the coins are already worth only spot price, no damage done. Stick around awhile and do some reading to see if we can addict you.

 

The erasers on ink pens were even better at shinning up dull coins. It had more abrasive materials in it then the regular lead pencil erasers had in them. Because lead pencil erasers rubbed the lead off of the paper, whereas the ink pen erasers sanded the ink off the paper.

 

Okay, I've been around some dirty coin in my history of metal detecting (sense the early 80's)
So, I've done different things to try and clean some of them (never a key date).
We've determined that cleaning is bad, even though coin grading services provide cleaning services, and the best I can gather they mainly use a chemical dip process, that if you do isn't acceptable. But, its probably not best to go there in any details.
If I had a coin that I was testing the results of cleaning it with a pencil eraser I would SKIP that altogether and go this route.
I would put the coin under a little stream of running water and get it as damp (wet) as possible,
Then I put a good sprinkle (cover it) with baking soda,
Then I would put a couple of good size drops of Dawn on top the baking soda,
Run it around with your finger just a bit, but just enough to make it a bit of a paste,
Do the same thing on the other side of the coin,
now take your thumb and index finger and lightly pinch the coin and rube the paste into the coin using a circular motions,
While your doing this every 15 seconds take your pinch off from the coin and reposition your pinch to help knead (mix) the Dawn/soda blend.
Continue this for say a minute or so, then rinse the coin.
DISCLAIMER!!! this is still a CLEANED coin, and could ruin the value of valuable coin.
This is amazing to how fast it will shine silver!!

 

Most chemical cleaning will be noticeable to many collectors as well. There are professionals, such as those working for the conservation services of the top TPGs that can clean some coins so it isn't noticeable, but that is very difficult to do. You need to be very knowledgeable of chemistry, metallurgy, and luster formation. Even at that, there are many coins that can't be conserved without the work being visible.

I like the disclaimer, but you should change the wording from "could" to ALWAYS lower the numismatic value (unless it is damaged to the point of being only worth bullion or face value)

 

It's not unacceptable for Joe Coin Collector to dip a coin. But he does need enough knowledge to know if it is an appropriate treatment, if the coin can handle a dip, and how to go about it without burning the luster off.
Now...an experienced eye can generally tell if there was a cleaning that involved friction. And that falls under "unacceptable cleaning". JMO.

 

They are your coins. Many respected people have carved them up due to being bored and later having excellent collecting /selling value, some have made them into jewelry and ignored any damage such as punching a center hole to make rings, some have (due to cultures) included them as wedding belts, some threw silver dollars to the air to shoot holes in them, some put them into milk to purify it. Most people would be happy receiving or purchasing some of these, but "cleaning" as a numismatic term is poorly defined as to severity and more often defined by intentions, which doesn't make sense chemically. Some solutions such as pure acetone ( except for the micro-quantity of horrible tasting, vomiting producing chemicals to stop you from drinking it ) does not affect copper, silver, gold, iron, etc. under conditions a human could survive.

The CDC has this about acetone.
https://wonder.cdc.gov/wonder/prevguid/p0000467/p0000467.asp#head004000000000000

Even the great and cautious state of California allows you to buy gallons if you are an adult.

It does not react or dissolve metallic coin materials by the vast majority of chemists. so it can remove dried secretions , common garbage and dirt, fresh fingerprints and not by itself damage the coins. Use of applicators though CAN cause scratching both visible and microscopic. Microscopic scratches can make the coin shine, but a grader can easily recognize the action. So dips and soaks can help "clean" coins and not leave any evidence or damage. Coinage made from ceramic or plastic ( such as older tax tokens coinage). IMO, Jim

 

Then look at all those beautiful sparkly scratches you have made...

 

So how do I clean my porcelain coins?

 

I was very clear with this method that it was vs a pencil eraser, and I was also clear about not cleaning a valuable coin at ALL!
If someone is looking at cleaning some coin with a pencil eraser of any kind, the baking soda & dawn is a better option, the puddle of slick dawn and light pressure is a FAR better option than a pencil eraser.
I never said there was a good way to clean a valuable coin, I've seen people use Comet Cleaner, I've seen gun cleaner solvent and a brass brush used, rock tumblers, get this, I've known people to have their wives save dryer lint and the soak it with salt water and put it and the coins in the tumbler, I've seen people soak them in Olive oil for WEEKS and brush them, but I've not seen anyone do any of the above to a valuable coin.
If the coin is one that a person is going to use a pencil eraser on (a worthless coin) then try the baking soda & dawn as a better option.
If some one is thinking about using steel wool, the pencil eraser is a better option.
Ol, I forgot this common method, a wire basket and a dish washer cycle.
But, again we're not talking about a valuable rare coin even in the OP (original post).

 

And good vs a belt sander...

 

Just not a valuable rare coin!

 

I've actually thought a lot about defining coin cleaning and I go back to this!
All the big Casinos in Vegas at lest at one time had GIANT coin cleaners that ALL the coins (millions of them) are ran through before they're circulated inside the casinos! They ALL did it (do it)! they want their coins to be shinny CLEAN! (Cleaned)
My wife pulls coins out of the washer machine from about every load of laundry she does, except for towels and underwear LoL! (Cleaned)
So, for the most part its possible that once a coin passes a certain time frame in circulation its not likely to NOT HAVE BEEN CLEANED! even purposely cleaned, even valuable ones.
I know people who will take yard sticks with a hook formed (cut) on one end and reach under the washer machines in laundry mats and drag coins out that falls out of the pockets and rolls beneath the washers (CLEANED)
I'm sure there is people here that has seen say copper cents in a collection that has finger prints etched into the surface of them, you know those raw brown well circulated Lincoln's ruined with a salty, maybe chemical coated factory worker finger print and the coin was put into the collection and LEFT for the salt or chemical to react to the metal because THEY CAN NOT BE CLEANED!!!!
Well, I know of only two somewhat ways to prevent this!
(CLEAN THEM) well, wash them, its not like its going to be their first bath.
But, how to do this???
Many very HIGH END collectors use acetone, but they use PURE! and they test it, how? they put a few drops on a clean mirror laying flat and let it dry, if it leaves a spots, its considered NOT PURE! and when they find some that test pure, they buy LOTS of it.
Next, for a single coin at a time they can be washed by putting a small amount of distilled water into a bowl, add a couple of drops of dawn and stir it together and let the coin soak in it for a couple of minutes, find a little brush (NON metal) with as soft of bristles as possible. Pull the coin out and gently brush it, have a second bowl of straight distilled water ready and put the coin in it for a rinse (make sure you have washed your hands with dawn just before starting the process) move the coins around in the rinse, remove it and pad it dry with a clean micro fiber cloth, then add it into your collection.

 

Most of the problems come from the surface of the coins being scratched, cracked , or chipped so cleaning solutions can penetrate into the more porous center, which can expand the coin enough to cause or increase breakage. I believe Europe ( Germany) and Asia ( China) made the majority of these. I have 2 someplace, but they had small surface cracks when I obtained them. So use a very small air hose Jim

 

I have quite a number of procelain notgeld, and have never cleaned any of them. Once fired, the ceramic surfaces are very stable and rarely react permanently with the environment (think of your coffee mug). Worst case seems to be dirt and that can be removed by soaking in water.

 

OK, as a follow up, and in the interest of full disclosure, here are some pics of some of the silver rounds I mentioned, that I used an eraser on. First I will address the 'Draped Bust' round. This is a problem girl. This round is un-reeded and was heavily tarnished, with black, ugly sections on both sides and the edges. Under close observation, you can see the micro scratches from the eraser treatment I did. It's 100x better looking than it was, and since it's just bullion, I'd say that's a plus. Also, this is really a no-name round, not even a date - I can hardly even find any examples of it online. She kind of looks like a hag. It checks out as 3-nines-fine, though, and 1 oz. of silver.

Next is the 'American Prospector' rounds. These had some ugly black places, but only needed a very gentle wipe to pick them up. These actually do have some collector premium (mine are from 1984). I hope I have kept that intact. With high magnification, you can see where I touched them, but only just barely, and it's only in a small place or two.

They don't look as nice as a 2022 Aussie Kangaroo, though!

 

oooh, me likey

 

Honestly, this is really a no brainer. It was an experiment. And no one has yet offered proof as to why using an eraser would be harmful. Where is the microscope evidence? For the coin collectors be more mindful of coin collecting history. Understand when the rules to not clean coins first started and why. Science and reasoning matter. Don’t shoot down an experiment just because your blindly following arbitrary rules without understanding why the experiment was done in the first place.

 

Honestly, this is really a no brainer. It was an experiment. And no one has yet offered proof as to why using an eraser would be harmful. Where is the microscope evidence? For the coin collectors be more mindful of coin collecting history. Understand when the rules to not clean coins first started and why. Science and reasoning matter. Don’t shoot down an experiment just because your blindly following arbitrary rules without understanding why the experiment was done in the first place.