Olive oil cleaning

[numismatic nut]

I have a dark (light, faint black) VG 1926 large cent. I have a cholate brown 1857 large cent next to it, and it looks bad. I was reading in a treasure hunting book, and the book said that olive oil takes gunk off copper. I know that you should only clean fresh metal detector finds, but still......

 

I want to know if I could use olive oil on the coin without causing damage. Is this possiable?

[bobh]

I have a dark (light, faint black) VG 1926 large cent. I have a cholate brown 1857 large cent next to it, and it looks bad. I was reading in a treasure hunting book, and the book said that olive oil takes gunk off copper. I know that you should only clean fresh metal detector finds, but still......

 

I want to know if I could use olive oil on the coin without causing damage. Is this possiable?

Surely this should be "1826" and not 1926??

 

I would only use olive oil if there were any green stuff ... "chocolate brown" is how old copper coins are supposed to look!

[just carl]

WOW! A 1926 Large Cent. I didn't know those were still used then. Might be for those large gum balls in the gum ball machines.

Just kidding of course. As to Olive Oils. I suggest NOT. The reason is sometimes what you read in a book, magazine, the internet, etc. is just something written by someone that has no idea of what they are saying. OR they may have left out many problems or differences in what they are discussing. By this I mean always remember that any product manufactured by people could be different than what someone else produces. Olive Oil is product of a manufacturing process and may well be different than the ones discussed in whatever you read. If all Olive Oils were the same, only one manufacturer would be required. If the one you try contains something that could eventually damage the coin, your loss. And then too there would be this oil film on the coin. So now you have to use something like Acetone to remove that. Then to make sure there is no residue, you now rinse in Distilled water.

Why not leave well enough alone?

[numismatic nut]

This coin is BLACK, not brown. I want it to look brown like the coin next to it.

 

This coin is also very strange. My scale meaasures to one tenth of a gram (.1g). The Red book weight is 10.89g. This coin's weight is between 10.2 and 10.3 grams. Under a through inspection, the surface fields look grainy. It looks like a counterfiet, but it has a good tonal sound. I am at a loss.

[numismatic nut]

Here are the pics of the coin. The top coin is the normal one. The lower is the 1826 that is dark.

[bill]

I'll defer to some of the copper collectors here, but I think both cents have natural toning. I don't think you can change the dark toning without ruining the coin. I think it is impossible to make it look like the other in the picture.

[just carl]

Here are the pics of the coin. The top coin is the normal one. The lower is the 1826 that is dark.

It does appear to be a nice coin. I really can not figure out why the less than what it should be for weight unless your scale is just off. If not the scale, then that is weird. As any coin tarnishes, tones, corrodes, etc it is actually combining with outside substances like Oxygen, Flourine, Chlorine, etc. And with Copper if in the worng area it could start combining with Carbon Dioxide and/or Sulfur compounds such as Sulfurous Acids in the air. Regardless as this happens the coin should acutally gain some weight, not loose.

I would still not recommend messing around with things you do not really know the end results of unless you just don't care about the possible end results of that coin.

[just carl]

However, taking a further look at that coin there is a definite amount of wear which could well explain the loss of weight.

In the past I've tried to bring back the original appearances of many coins. My best results were with the usage of a jewlery Cleaner from Walmart. Of course the end results was a obvously and extreamely noticable cleaned coin.

[UncleBobo]

Leave well enough alone, the old gal looks fine to me.

With the heavy wear, I think any attemped cleaning will leave you with dark outlines around the lettering and other raised surfaces, which I would find much more annoying than a uniformly dark coin.

[NumisMattic2200]

No. Don't clean coins!

[hiho]

No. Don't clean coins!

 

Save the olive oil for cooking and don't clean old coins!

 

There is no UNDO button.

[just carl]

When I saw this post again, I remembered I had a Large Cent I was given due to it being really dark and pitted pretty bad. So I took it and placed it in a glass jar with a layer of Olive Oil for experimentation. After over one day and nothing happening, I rinsed it off, dryed it and placed it in a jar of Acetone and placed it in my garage for one day. Then placed it on a picnic table for another few days in the Sun. Since someone mentioned a web story about Acetone and water in the Sun making Copper coins vanish, I added some water to that jar. One more day in the Sun and I forgot all about that. It's still there, I hope. I'll go look in few minutes and in case no kids have stolen that coin and if no changes, I'll try something else next.

[numismatic nut]

I have read to soak the coin for a week at least.

[bobh]

Since someone mentioned a web story about Acetone and water in the Sun making Copper coins vanish, I added some water to that jar. One more day in the Sun and I forgot all about that. It's still there, I hope. I'll go look in few minutes and in case no kids have stolen that coin and if no changes, I'll try something else next.

Just so people don't get the idea that I am making this all up:

Copper and acetone reaction

 

Since I'm not a chemist, nor do I pretend to be one, maybe some other readers who are chemists would like to comment.

[numismatic nut]

Since I save nasty looking lincoln's from circulation, I toyed arond with copper. I found that anything that I put on the coin had no positive effect. Acetone took the circulation 'grease' off, and the coin was open to enviormental factors.

 

I think I will not do anything untill I research it myself (and ask here).

[just carl]

Just so people don't get the idea that I am making this all up:

Copper and acetone reaction

 

Since I'm not a chemist, nor do I pretend to be one, maybe some other readers who are chemists would like to comment.

People constantly refer to that article and it does really sound authentic. However, many, many things on the internet do sound authentic. If you read the article carefully notice they used Copper Foil, not a Copper coin. Also, it is noted that green crystals appeared. The article does not specify how clean the Copper foil was, nor how pure the Acetone was nor what exact proportions and clarity of water was mixed in the Acetone. Also, omitted was the exact type of containers used.

Although this article appears to be authentic, way to much is left out.

I've already experimented with Copper coins in Acetone, with different proportions of water, in Sunlight, dark, for days, in glass containers and just about anything else to aquire those results.

My conclusion is I would need the same SUN they used, mine just doesn't work like theirs does.

[just carl]

Not sure if I mentioned this previously but I've had about 10 Copper cents in a glass jar of Acetone and some water now for several weeks. Occationally in the Sun, but put away at night since not wanting to temp a neighbor to borrow them. So far they all look the same as the day I put them there. The original reason was they were all really messed up with dirt, grime, corrosion, etc. So nothing to loose. I've also been playing around with a large cent someone gave me that was really dark and dirty. I've been taking periodic photos of that one and so far, not much difference.

[numismatic nut]

Not sure if I mentioned this previously but I've had about 10 Copper cents in a glass jar of Acetone and some water now for several weeks. Occationally in the Sun, but put away at night since not wanting to temp a neighbor to borrow them. So far they all look the same as the day I put them there. The original reason was they were all really messed up with dirt, grime, corrosion, etc. So nothing to loose. I've also been playing around with a large cent someone gave me that was really dark and dirty. I've been taking periodic photos of that one and so far, not much difference.

 

That is intresting. But the question is what will happen to the coins after you take them out of the acetone.

[jugoslavija_post]

Those are some nice coins, numismatic nut.

[just carl]

That is intresting. But the question is what will happen to the coins after you take them out of the acetone.

Nothing at all. I'll eventually take them all out and rinse them with distilled water, blow dry them and they will look pretty much the same as the day I put them there. I just took the large cent out and tried the Salt and Vinegar method, then some Lemon Juice and finally some jewlery cleaner Still can't seam to get rid of that dark coloration. I sometimes wonder about the accuracy in composition of our coinage way, way back. I know what the books all say but that is what the government told the ones that put those statistics in thier books. Now for instance if that is not exactly true of some large cents being Copper, HMMMMM.

[gemstocks]

I have a dark (light, faint black) VG 1926 large cent. I have a cholate brown 1857 large cent next to it, and it looks bad. I was reading in a treasure hunting book, and the book said that olive oil takes gunk off copper. I know that you should only clean fresh metal detector finds, but still......

 

If you don't like the coin the way it is you can't lose anything by trying olive oil. If it doesn't work remove the oil but putting the coin in kitty litter for a few days. That will remove it without making any other changes. However, use fresh kitty litter or your coin will smell like amonia.

 

Gemstocks

[numismatic nut]

I am trying to 'clean' the coin without damaging it. Kitty litter is abrasive, and would harm the coin.

[just carl]

If you don't like the coin the way it is you can't lose anything by trying olive oil. If it doesn't work remove the oil but putting the coin in kitty litter for a few days. That will remove it without making any other changes. However, use fresh kitty litter or your coin will smell like amonia.

 

Gemstocks

Once more a possilbly dangerous suggestion. People just don't realize all the differences in products that are possible. And true most kitty litters are abrasive, but without knowing exactly what that product contains, it well may do a lot of damage to the coin.

[bobh]

Thought I would get the discussion rolling again. Here's an example of how olive oil can be used to get rid of verdigris:

 

BEFORE:

 

AFTER:

 

I had these coins under the oil for 2 or 3 MONTHS. Only "extra vergine" olive oil should be used for this kind of thing because it contains the least percentage of fatty acids (less than 0.5%, I believe) compared with cooking quality olive oil, which can contain up to 2% fatty acids.

 

You can see that the "after" pictures are somewhat lighter, but most of the patina is still in place. No rubbing or scraping was used; on tough cases, it might be necessary if the verdigris is very thick. However, you might not like what you see once you get down to the bottom of it! In this case, it was a very thin, but annoying, patch of green on the reverse.

 

In order to remove the oil residue afterwards, I used a simple pH-neutral hand soap with distilled water and rinsed copiously afterwards (actually, the water wasn't distilled, but our household water in Zurich is very soft, i.e. contains very few minerals. But distilled water would be the best). I have had some strange reactions when using acetone to remove the olive oil, although after the soap and water bath and air drying, it shouldn't hurt to dip it quickly in acetone if you are paranoid about any remaining oil...

 

As with any cleaning methods, YMMV; caveat emptor; etc.

[thedeadpoint]

YMMV?