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 Replies: 23 / Views: 3,372 |
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Valued Member
Canada
242 Posts |
I was hoping for some expert opinions. I'm still very new to collecting coins. I've been buying both cleaned and uncleaned coins. For the uncleaned coins, I've been soaking them for months now in either oil or distilled water. There are 3 options that I've been looking into: 1. I'm probably going to buy a lab shaker - something like this: http://www.midsci.com/lp/Lab_shakers.htmlI would put some coins in a plastic container within distilled water on top of the shaker, so that they don't touch either other or any other metal. The shaker would create a miniature 'wave' of water that would go over the coins, and forth. In my undergrad, I did a lot of research where we used these. 2. I haven't picked which shaker to buy yet, but some of them are also incubators. e.g. something like this: http://www.diamed.ca/shakers-mixers...-p-4101.htmlThis way, you can heat the coins gently (e.g. 40oC), in addition to moving the distilled water over them. 3. I also have a sonicator coming in the mail. This is (I think) much more gentle than electrolysis, which I've read should never be used for ancient coins whatsoever. I've read both positive and negative reviews about sonication though - many think that it is safe to use, as long as you are very conservative with the frequencies used. Does anyone have a strong positive or negative opinion about any of these options? The most gentle to me would seem to be the shaker method (no heat), but I'm very novice at this, and I don't want to ruin any coins! I would first experiment on very poor quality coins/slugs to get the settings right. Thanks! |
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Valued Member
 Canada
242 Posts |
By the way I've been reading everyone's posts since joining and learning a load from this forum - I just say, it's a superb resource! My own goal right now is still to find a 12 Caesars' set...I've found 2 on ebay, one of which was mentioned on CCF...it seems overpriced. The other was about half the price, but had one replica. |
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Pillar of the Community
United Kingdom
3626 Posts |
Seems a tad expensive. Personally, mine are in plastic tubs and when I walk past them, I pick them up and give them a shake.
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Bedrock of the Community
Australia
21788 Posts |
pp has a more practical way of doing things.
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Valued Member
Canada
242 Posts |
I can most likely buy a used one from a university that is looking to replace their's... The advantage of the shaker is that there is a constant movement of water over the coins, so I thought that this might clean them more efficiently. I'm trying to create a bit of a set up for cleaning ancient coins.
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Pillar of the Community
United Kingdom
3626 Posts |
Lol Sel :)
I don't know that it would be more efficient. I don't know the science behind it but I was under the impression that the various minerals, crud etc, leach into the distilled water. But whatever floats your boat.
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Pillar of the Community
United States
4973 Posts |
if I had some of those things just lying around (i remember them well from my college days) I may give them a try, but I think any small benefit you may get from increasing the temp or the constant agitation wouldn't be worth the cost.
sometimes i'll but my coins in south facing window (or even outside on myd deck) and let the sun warm them up a bit. in the summer I've actually made the water almost to warm to touch. I think agitation would help with loose dirt (i'll give them a hand swirl as pish does every now and them), I don't think it would help much with most of the gunk on dirty coins.
I'm not sure about sonicators, I know they are used to clean jewelry sometimes, but I don't know if they are safe to use on coins or not. from a quick google search, i'd say they are also pretty darn expensive.
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Valued Member
Canada
242 Posts |
Thanks chrsmat. Very interesting about using the sun - I wonder if the radiation may also help to some extent. It seems that radiation may actually 'help' or further develop the patina in some cases - e.g.: https://books.google.ca/books?id=jh...tina&f=falseI have pretty good connections with a few universities, so I ended up finding a used, lab-grade sonicator for $50 (Canadian dollars). I've been searching theses and conservation groups' papers on this, and so far it seems promising...e.g.: http://www.digbible.org/restoration.htmlI don't know very much about patina composition other than it generally being copper oxide/cuprite. But I'm going to ask some chemists of their view, and likelihood of harm. I was thinking of trying to create some sort of step-wise process for cleaning, with manual cleaning in between, e.g.: 1. distilled water bath with a shaker, with or without heating 2. oil bath with shaker, with or without heating 3. sonicator |
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Pillar of the Community
United Kingdom
3626 Posts |
I have one of those sonic things for cleaning jewellery, never used it for coins. It is not a professional one and the longest it runs is for 4 minutes. I would be forever switching it on. Certainly wouldn't use "jewellery" cleaner in it though.
You will find that if you buy a batch of coins (unless provided by a metal detectorist) they will be different depending upon where they have been lying for the last 1700 years or so. Some may take a couple of hours, and some may take months of soaking.
There are a couple of chemists on the forum,they may put in their two penneth.
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Pillar of the Community
United States
513 Posts |
In theory heat may loosen up some things, and agitation should keep 'new' water flowing over the coins, so both should help. Whether the difference would be noticeable I have no idea. Neither of these would damage a coin in any way I can imagine unless you really crank up the agitator.
The sonicator I could see doing some damage to the parts of the coins touching the bottom of the machine or any coins running against each other. It might be effective in short bursts though. My advice would be to go buy one of those cheap vibrating toothbrushes and stick it next to a coin in a bath of water and see if that does anything.
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Valued Member
Canada
242 Posts |
chuy1530 - that's not a bad idea about the vibrating toothbrush...
I would put the coins on some sort of plastic base within the sonicator, and clear of adjacent coins, so there was no metal on metal contact. Or another idea I some somewhere was to have the coins individually hanging in the sonicator water bath within something akin to a tea bag.
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Valued Member
Canada
242 Posts |
pishpash - the sonicator I bought is a lab-grade one, so it should be fairly durable. We'll see how it works when I actually receive it though.
I figured the lab shaker couldn't be worse than just soaking in distilled water, and might be a bit quicker. I have some that are nearly a year old by now that have been soaking...they're very slowly improving, but at least to date, I haven't done much else other than rub them with my fingers for a bit every now and then. I've been trying to be as gentle as possible on these.
I figured the 3, now 4 variations I can try to experiment with are:
-sonication/cavitation
-constant agitation/lab shaker
-heat
-and now radiation based on chrsmat's post
I have to say, I really enjoy the idea of buying uncleaned ancient coins - it's almost like a bit of a treasure hunt...
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Moderator
 United States
23731 Posts |
I haven't cleaned coins for sometime now but when I did I used a ultrasonic machine in the process. In conjunction with soaking in olive oil I would run the coins in the heated ultrasonic machine. The results were excellent.
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Valued Member
Canada
242 Posts |
Thanks echizento...that gives me confidence that this might work!
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Pillar of the Community
United Kingdom
3626 Posts |
My ultrasonic is supposed to be for jewellery and it came with a plastic basket. I also have plastic baskets that came in jewellery dips.
By the way, I have used an electronic toothbrush for cleaning coins that have been in soak, and it appears to be no better than a normal toothbrush. Never thought of it as an agitator. Might be a bit heavy on the battery though.
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Pillar of the Community
1121 Posts |
I have been down this road and the four BEST things for cleaning 'uncleaned' coins are:-
1/- 'Demineralized Water' (PishPash) and
2/- 'Olive Oil' (Medieval)
They are undoubtedly the two BEST (safest) commercial cleaning agents for 'uncleaned' coins. You can add to that
3/- 'Picking' at the 'crud' with a wooden (Bamboo) pick (PishPash) and
4/- plenty of 'Patience' (Medieval)
I have also used a jewellery 'ultrasonic' cleaner which (in theory) would be excellent, however I have noticed no appreciable assistance in cleaning old coins when using this method.
I hope this helps you. It did me.
Edited by Topcat7
12/31/2014 3:43 pm
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Replies: 23 / Views: 3,372 |
Posted 12/31/2014 09:30 am
