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Author Topic: Some Tools and Tips  (Read 628 times)

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Offline Virgil H

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Some Tools and Tips
« on: May 24, 2023, 04:10:19 pm »
I just attended the last session of the ANS Lyceum on Collection Management and Conservation. This session was by David Hendin. I have communicated with him in the past on some specific bronze coins of mine that need cleaning and he was super nice and helpful. He gives a great presentation. From my notes, some items that people may find helpful and interesting. These notes all apply to bronze coins only. Some of these are pretty well known, others maybe not so much, some might be controversial.

1. Manual cleaning is always better than chemical. Chemical cleaning is a last resort.
2. He is fairly adamant that the average person shouldn't try to clean coins as it is so difficult to do well and the potential for making a coin worse is high.
3. Never use olive oil or any oils. He is a distilled water guy.
4. He showed a photo of his tools. This is what really interested me and surprised me. Not a scalpel in sight. Tools are: binocular microscope 10x-30x; one soft bristle brush made with hair (very soft toothbrush also works); one whetstone for flattening needle points; one pencil with eraser; and four pin vises that hold various sizes of flattened needles, all very small needles. That is it.
5. For bronze  disease, he uses 2-5% solution of Sodium Thiosulfate or 5% solution of Sodium Sesquicarbonate, either in distilled water. The numiswiki article on one of these substances seems to track Hendin's recommendations, although some other stuff in the article he wouldn't agree with, such as olive oil and Ren Wax.
6. He does not like Ren Wax. This somewhat surprised me because it is recommended a lot. I personally just don't like the look it creates, although I am sure I have a few coins where it was used. To me, it looks unnatural. I suspect Hendin feels the same way. In any case, it confirmed I will never use it.

There was a lot more, this is what I remember best. I have some Phillip II bronzes and late Roman coins that have been soaking in distilled water for ages. Time to get a couple pin vises (they are cheap) and pins and get going. His method is pretty slow, but he gets incredible results. He also discussed chemical cleaning and how difficult cleaning silver is. The pins will scratch a silver coin.

Virgil

Offline SC

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Re: Some Tools and Tips
« Reply #1 on: May 24, 2023, 06:45:05 pm »
I used pins, a pin vise and a sharpening stone before starting to use x-acto gives and scalpels (and a sharpening stone).

I think both have their uses.  I find it easier to scratch a coin with a pin, though it can easy with a blade too. 

But if you have to clean a relatively large flat surface (more than a few mm wide) I find a blade beats pins.

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(Shawn Caza, Ottawa)

Offline Virgil H

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Re: Some Tools and Tips
« Reply #2 on: May 24, 2023, 11:33:12 pm »
I was looking at these needles. He said he uses sewing needles he cuts and then flattens. These needles are tiny, but I assume they are large for a sewing needle, maybe for wool work or something, but not as thick as one for leather, so this must be some serious detailed work and here is where I can see using a 20X microscope maybe. I use a number of tools, most that are not overly hard like the needles or scalpels, but I do use a scalpel, which is needed for getting off a lot of crustations. What size needles do you use? There are also needle tools sold for working clay that are in various sizes, some pretty small. These are all-in-one type tools, I worry about getting a vise that might not hold needles below a certain size. None of this stuff is at all expensive, so no harm no foul, and I would like to give it a try. Sometimes I think the scalpel is too large, although it works pretty well most of the time.

Thanks,
Virgil

Online Joe Sermarini

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Re: Some Tools and Tips
« Reply #3 on: May 25, 2023, 02:03:36 am »
I believe chemical cleaning is better than manual cleaning for good silver and gold. They are not damaged by the chemicals I use and are easily scratched by manual cleaning. (I have not actually cleaned with chemicals for a few years.)

For gold, I use sudsy ammonia. A coin can be soaked, then wiped with a very soft cloth. Rinse very well with distilled water and dry. This will remove oils and dirt on the coin and restore the shine (if it is there under the oil and dirt).

For silver, I use ammonia gas created by slowly pouring boiling water into a little baker's ammonia with the coins suspended above in a screen (must be done outside and do not breath the fumes, they will damage your lungs at least temporarily). Pour the water slowly (but not so slow that you are breathing the fumes) until it covers the coins and leave them in the solution until the bubbling stops. Repeat as needed. Rinse very well with distilled water and dry. This will remove all toning. Don't use it if you want to keep the toning. If the silver is debased, the surfaces may be slightly rough (frosty) after cleaning. Don't do too many coins together. I hesitate to describe this method, it really can hurt your lungs if you are not careful.

I use Ren Wax mostly on coins that have been treated for bronze disease. (Again, I haven't actually used it for quite a while.)
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Offline Serendipity

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Re: Some Tools and Tips
« Reply #4 on: May 25, 2023, 02:57:14 am »
I personally would never use metal tools like needles or scalpels to clean ancient coins. I saw a very interesting documentary on the conservation work involved in the Staffordshire Hoard which is the largest hoard of Anglo-Saxon gold and silver metalwork found in Britain. What stuck in my mind about the conservation work was how they always carried these plastic bags full of twigs with leaves. They would remove the leaves and painstakingly clean the hoard with the twigs no matter how many twigs got blunted and how long it took. This resulted in no telltale hairline scratches to the artefacts. It also saved their conservation funds from being squandered on loads of overpriced wooden toothpicks.

Offline Nathaniel N2

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Re: Some Tools and Tips
« Reply #5 on: May 25, 2023, 03:00:26 am »
I would add my two cents on non-professional coin cleaners. Most, if not all, of what I clean is worth less than $50. No professional is going to sit there with my 3rd or 4th century common coins and clean them because there is not likely anything special there and we already have millions of them. So long as I am careful and get good results, if not absolutely perfect, it's better than the coin staying dirty forever. There have been a couple of coins I've butchered but they were common and in extremely poor condition plus it was a while ago when I was extremely new. Gotta learn somehow.

I like to wax my coins as a protection for handling and I like the shine. Also, it has been important on some really fragile patinas to stabilize them as much as possible.

Maybe I'll upgrade to a microscope sometime but for now, a magnifying lens light is enough for me.

I use a bamboo skewer, pin, scalpel and lots of distilled water.
Looking for more underpriced uncleaned coins. Let me know if you find them.

Offline Nathaniel N2

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Re: Some Tools and Tips
« Reply #6 on: May 25, 2023, 03:04:52 am »
I personally would never use metal tools like needles or scalpels to clean ancient coins. I saw a very interesting documentary on the conservation work involved in the Staffordshire Hoard which is the largest hoard of Anglo-Saxon gold and silver metalwork found in Britain. What stuck in my mind about the conservation work was how they always carried these plastic bags full of twigs with leaves. They would remove the leaves and painstakingly clean the hoard with the twigs no matter how many twigs got blunted and how long it took. This resulted in no telltale hairline scratches to the artefacts. It also saved their conservation funds from being squandered on loads of overpriced wooden toothpicks.

It surprises me how much cleaning can be done with a simple toothbrush. It can be slow at times but the results are often worth it and you won't do any damage with a soft toothbrush.
Looking for more underpriced uncleaned coins. Let me know if you find them.

Offline Virgil H

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Re: Some Tools and Tips
« Reply #7 on: May 25, 2023, 05:40:06 pm »
Thanks for the interesting and useful comments. On silver, what Joe said is pretty much what Hendin said. I will probably never try to clean silver, I don't think I have any silver that "needs" cleaning. I agree that I almost only clean coins I can afford to ruin, late Romans. I do have a handful of Phillip II bronzes that, monetarily, were not expensive, but those I really want to be careful with. And, for all my coins I plan on cleaning, I believe doing so will increase their value (even if a low value, my per coin cost was very low for the lot I got). I like the pin idea because they are so small and, with a microscope, I think they will be useful. I use a lot of brushing and bamboo skewers, etc., but the metal of a scalpel or pin can really get crud off.

Virgil 

Offline Ken W2

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Re: Some Tools and Tips
« Reply #8 on: May 31, 2023, 10:57:23 pm »

Nice thread guys. On silver, I rarely clean at all, but occasionally I’ll prod a little with bamboo or carefully with a No. 11. On bronze, I have used cut off sewing needles and straight pins, but never flattened them with a sharpening stone. Might try that. Of course I start with dw and brushing, but have pretty much migrated to No. 11 exacto blades as my tool of choice. I also like diamond encrusted dental bits for tougher encrustations. 

Offline v-drome

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Re: Some Tools and Tips
« Reply #9 on: May 31, 2023, 11:50:28 pm »
My biggest problem comes when I try to remove an encrustation and it pops off with a big ole chunk of the surface, leaving a big ugly hole in the patina. :(  I guess that is where experience comes in, to know which ones are worth trying and which ones to leave alone.  Any advice would be appreciated.

Offline Nathaniel N2

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Re: Some Tools and Tips
« Reply #10 on: June 02, 2023, 08:40:15 pm »
For big encrustations, in my experience it is better to go from the top rather than the bottom. Slowly break them down with a diamond dusted tool from the top rather than prying from the bottom, you can only pull up patina if you pull up.

For silvers, I have found a few really dirty denari in my uncleaned lots, yay! I have used Q-tips and lemon juice to remove this dirt. I'll post a few before and after pictures. I roll the Q-tips, not even swirling them, until they come up clean.
Looking for more underpriced uncleaned coins. Let me know if you find them.

Offline Virgil H

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Re: Some Tools and Tips
« Reply #11 on: June 03, 2023, 04:24:46 pm »
Those look great, Nathaniel. Hendin also mentioned lemon juice for silver. I haven't bought an "uncleaned" lot in a long time. My experience with them was just not very satisfying. I also never found any silver!

Virgil

Offline Nathaniel N2

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Re: Some Tools and Tips
« Reply #12 on: June 03, 2023, 09:01:26 pm »
Thanks. Good to hear that Hendin also condones lemon juice.

I've had mixed results with uncleaned coins depending on the dealer. Spending more than $10 normally gets some great coins. Alternatively, auctions sometimes have uncleaned coins that you can purchase and clean up resulting in some major savings. I'm still kicking myself a bit for not getting a Trajan Sestertius that I saw two months back It went too high for me though (but did it really?).
Looking for more underpriced uncleaned coins. Let me know if you find them.

Offline v-drome

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Re: Some Tools and Tips
« Reply #13 on: June 03, 2023, 09:33:22 pm »
This is a repost from an earlier topic.  I have come to really appreciate uncleaned silver, though in some cases it may be necessary to treat them.  Uncleaned denarii are much rarer than cleaned ones, these days.  "Here are some denarii from Caesarea Maritima to show the variety of surfaces that can occur with silver coins in a moist seaside environment.  All are as found with the exception of the Hadrian, which was even more coated in green than the Pius.  This was cleaned about 40 years ago, probably with household ammonia, which as I mentioned can be risky if the silver has a high copper content.  Ammonia dissolves copper and can leave a shiny surface that may be porous or brittle in the worst cases.  I was lucky with the Hadrian and I think it looks very nice, but I have left the others as they are."   https://www.forumancientcoins.com/board/index.php?topic=112296.0

 

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