Ultrasonic cleaners

[Raoul]

Hi everyone, can anyone tell me if its safe to clean coins with a ultrasonic cleaner. Many thanks Raoul

[mint_mark]

I've only read about it and not tried it... I seem to remember the conclusion being that it can remove the dirt from coins but it can also remove any patina too.

Here's a good link which always makes me think twice before trying anything!!

http://www.ancient-times.com/info/cleaning.html

[Sylvester]

I'm usually of the old skool, quite ardently anti-cleaning, cleaned coins, i won't touch em.

Although i do realise for dug up coins and coins over a certain age like ancients it's a whole different ball game, then i'm a bit more understanding and liberal.

My advice is, if cleaning is non-essential (i.e you know what the coin is and you can see the date and everything) then leave it well alone. You should only risk cleaning a coin if it is encrusted and you can't identify it until you've 'curated' it.

[william]

Hi everyone, can anyone tell me if its safe to clean coins with a ultrasonic cleaner. Many thanks Raoul

What is an ultrasonic cleaner? Thanks.

[mint_mark]

Well, I did a web search and this one came top of the list... it has an explanation of what it does.

http://www.technika.com/Sper/s100005.htm

So, very high frequency vibrations caused by exploding bubbles of all things! I imagine the vibrations literally "shake" the dirt from the object, which suggests that the object has to be much more solid than the dirt. A metal coin is (hopefully) pretty solid, so this explains how such a cleaner can remove the patina from a coin... after all, a patina is just a smooth layer of accumulated dirt I suppose.

Learn something new every day...

[Sylvester]

So, very high frequency vibrations caused by exploding bubbles of all things! I imagine the vibrations literally "shake" the dirt from the object, which suggests that the object has to be much more solid than the dirt. A metal coin is (hopefully) pretty solid, so this explains how such a cleaner can remove the patina from a coin... after all, a patina is just a smooth layer of accumulated dirt I suppose.

They used them in the mineral collecting world...

[Emperor Oli]

I believe they use the machines for cleaning parts of pocketwatches too

[Sylvester]

I believe they use the machines for cleaning parts of pocketwatches too

so that's why my pocketwatch is playing up!

[Raoul]

Thanks Mint_mark, William check out Mint_marks web link it explains it spot on.

I have been thinking about buying one ,they start out at $100.00 and just wanted to know if it will harm the coins before spending the dollars.

Thanks Raoul

[william]

But the one on Mint marks site was $96!!

[Chris Perkins]

A Chinese chap once contacted me, keen to show me the results of ultrasonic cleaning. He worked in the jewellery trade and showed me some interesting before and after pictures of a Chinese coin (that I can't find now!).

It certainly looked more pleasing than if it had been polished/whizzed/cleaned, but it still look kind of artificial. Saying that though, I don't really know how high grade natural toned Chinese coins are supposed to look.

He suggested I could send him some coins for him to clean. I believe he was genuine, but he said that the post where he was was very insecure, so nothing became of it.