The truth on Q-Tips, cotton, and stern voices scratching coins

Hi all – I keep seeing claims that Q-Tips, cotton cloths, cloths in general, paper, and maybe loud music scratch coins.

I'm confused by these claims given the physics I thought I knew. I'm no tribologist, but the scientific claim I'm familiar with is that scratching requires that the scratching object be harder than the scratched object. Or possibly that it be at least of equal hardness.

Is that purported scientific claim incorrect? If it's correct, then what are people talking about when they claim that a Q-Tip can scratch a metal object like a coin? How is that possible?

Note that even if that claim is incorrect, it doesn't necessarily follow that a cotton swab can scratch a metal object. That would still need to be established. What's the mechanism, the physics, of a cotton swab, or cloth, scratching metal? What's happening down there in the weeds, so to speak, where the cotton fibers contact the metal?

To be clear, y'all aren't talking about foreign matter in the swabs and cloths right? Like sand or a tiny sliver of shrapnel your coin gear picked up in Iraq... The claims I've read seem to be saying that a Q-Tip is literally scratching a metal coin, all by itself, no contamination, just the cotton fluffy fluff. I'd like to nail this down to strictly cotton, fabric, paper as such, free of contamination.

I'm mostly thinking of gold and silver coins. They are indeed the softest of the coin metals, but even pure 9999 gold bullion is much harder than cotton or paper cellulose, so it's still a mystery to me how scratches would occur.

I'm also interested in your thoughts and experiences with paper in particular. Can clean paper scratch coins? Is there a certain type of paper that would definitely not scratch coins? (Maybe pure cotton or linen paper, like the primo Crane sheets?)

I've been thinking about using elegant paper envelope-like pouches or sleeves as packaging for individual coins, when shipped and so forth. Maybe brown kraft paper like grocery bags are made of. Not for long-term storage. And silver will tarnish without airtight storage of course, but even silver coins are normally shipped by dealers in crude plastic flips that are completely open on one end, so tarnish-proof packaging is not the norm anyway. I'm concerned about scratches though. Anything graded or precious will already be in a slab, so this really only applies to standard bullion coins and bars, like your standard BU 2021 Silver Eagles, Maples, etc.

Thanks.

 

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First, why are you wanting to use a cotton swab on a coin? Obviously to remove some type of debris. The debris embeds in the swab and becomes like sandpaper. As far as paper goes, what type, what contamination has it been exposed too, and what is the composition? Edit: spelling.

 

I don’t see the harm in a cotton cloth or Q-Tip or anything like that but I don’t see how they would be helpful either.

I guess my question is, why would you want to use either on a coin?

 

Lol

 

Sorry, I tried . Just couldn't get passed the first sentence ,

 

I use a Q-tip sometimes when I dip coins. Although I never put force down, as rubbing it against the surface can leave hairlines. Just lightly enough to get the solution on the coin and then a thorough rinse.

Q tips, Cotton, Paper, they can all scratch coins. In fact, just about anything can. The materials mentioned are known to leave hairlines on the surface of the metal.

I am not a scientist but I believe it is the malleability and finish of the metal that can be scratched by cloth. Cotton is still an abrasive material albeit softer than most other fabrics. Combined with force, a Q tip will leave very light scratches as it moves the metal. Hairlines are usually looked over on circulated coins (Unless it's strong), but become very noticeable in AU+ grades, usually leading to details grading.

Try taking two deep mirror proof coins, rubbing one a few times with a cotton cloth, and comparing them. It's the same as polishing a surface as it leaves small hairlines. Though in this case it is damaging to a coin.

Oh, and as other people have said, Q tips can pick up dirt and drag it along the coin, scratching it even further. If you use a Q-tip, make sure not to put firm pressure on it.

I am sure there is a more scientific answer than I can explain. Hope this helps.

 

I’ll forget coins and move straight to your point. Go visit the old Montana State Prison. Time is the best weapon a crimson has that is locked behind bars. Some of those prisoners took toilet paper, yes, regular soft to and twisted it into ropes and those toilet paper ropes were strong enough to hang a man. It’s the texture that counts and a soft q-tip can and will scratch a hard coin.

 

How do you think a coin gets worn down to an "About Good" level in circulation? It isn't because it comes in so much contact with things that are obviously harder than coinage metals.

 

Excellent point. If it takes something harder than the coin metal to scratch it or wear it, how does it wear away in normal commerce. Also, if you have a proof coin, take a Q-tip and scrub on the mirror finish and then examine it in a strong direct light at several angles and I think you will see hairlines. Try it.

 

How precious. This person's never heard of the concepts of friction or errosion. Where softer items produce wear on harder items through simple contact over time i.e. hairline scratches.

Psst. Kraft paper, because of the manufacturing kraft process, off gasses chemicals that are alkaline, and is unsuitable for coin storage. You may get away with a short term for shipping/delivery purposes but if the receiver doesn't know and leaves it like that for a long period of time they might find an ugly black coin when they look again.

And yes music can scratch a coin if it's loud enough and causes vibrations that move the coin against another surface which will cause friction and wear on the coin.

circulated coins have friction wear. hands/ pockets/purses, and other coins, all as hard or softer, but not harder than the coin, causing wear through friction slowing wearing a coin down to nothing. And yes even a little bit is detectable with magnification.

 

Most paper manufacturing processes use sulfur compounds. In general, coarser and darker papers seem to bear more sulfur. Sulfur is the main culprit in tarnishing (toning) coins.

Kraft paper seems like a terrible choice for shipping coins, unless you're trying to abrade and tarnish them.

As for "paper is softer than metal":

1) Paper is not pure cellulose. It usually contains mineral binders or fillers, and can have dust and grit on its surface (as can the coin itself).

2) It's not the case that "softer things can't scratch harder things". I got to try out an experimental diamond-coated frying pan, supposed to be "non-stick and the last word in scratch resistance". I scratched it up very nicely with a table knife.

3) Arguments from first principles are compelling, but they don't trump real-life experience. Grab a shiny metal object and a sheet of paper, rub on the metal for a while with the paper, and see for yourself.

 

So, If I used a Q-tip on a coin removing whatever you could tell I USED A Q-TIP you could tell .. agree paper is made from wood and will scratch.. your not sanding down the coin so if I gentlely dab on a spot and rinse you could tell.. guess I wont do that now.... that hip hop and rap music will scratch your head...

 

Great stuf. How about a stream or drip of actone for 1 or 2 hours would that damage the coin ?

 

No one mentioned water. One of the best solvents around. It made the Grand Canyon.

 

I agree, it is more the finish of the coin can be visibly disturbed under magnification.

 

Whatever happened to Ancients yes, any other coin no... That's my story and I'm sticking to it! Enjoyed the post, thank you.

 

Q-tips are for wussys.

Only real men use brillo pads! Gets the job done quicker!

 

Paging @physics-fan3.14 - I believe he once did an experiment where he rubbed an acetone Q-tip against a low-value modern Proof coin, and IIRC it was actually quite difficult to make hairlines.

However, that was a clean Q-tip - if there had been dirt from the coin accreted on the Q-tip, it probably would have been a different story.

 

With regrets, I know from personal experience that any solid material, no matter how soft to the eye or touch, will scratch the surface of a mirror Proof field or device. It will also remove the toning to a lesser extent. Some posters have stated this and they are correct. It is the accrued residue on the polishing material that creates the hairlines. The chemical structure of surface oxides on the coin are crystalline and thus have sharp points. The polishing medium picks up the crystal oxides and in turn rubs them against the surface. I have found a liquid medium with an airblast is the only way to prevent hairlines when cleaning a mirrored coin.