Author Topic: Is Olive Oil safe for all metals?  (Read 6342 times)

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Offline Rishabh Jain

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Is Olive Oil safe for all metals?
« on: April 22, 2013, 06:12:39 PM »
Hello,

I know some people are against cleaning of coins but I want to try it so I can learn something.

So, I recently got some coins and most of them are dirty. I want to clean them and I thought it would be safe to soak them in olive oil for a  few months or maybe years.

I trust olive oil because it has worked on some of my coins in the past and it seemed way safer than electrolysis, which has destroyed some of my coins.

My question here is, is it okay to soak coins of all metals (Nickel, Silver, Copper, etc) in olive oil?

I am pretty much sure it is safe but this time it is about a pretty valuable coin (Not much, but it is my first Silver coin and it is pretty old too.) so I just wanted to be completely sure if it will be all right.

Also, please tell me for how long I should keep the coin in Olive oil. The silver coin has turned black but the inscriptions and readable. Some people might say that this does not require cleaning but I want to try it.
I would like to buy the Bull Anna series.

I will also buy single coins of this series.

Please message me with your price and an image of the coin/coins.

Offline Figleaf

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Re: Is Olive Oil safe for all metals?
« Reply #1 on: April 23, 2013, 01:04:30 PM »
In principle, olive oil is acidic. In fact, the quality of olive oil is measured by its acidity. In practice, the acidity of even the worst (Spanish) olive oil is so low, that it is quite safe. I once forgot some Chinese cash coins in (Italian) olive oil for almost a year. They came out fine, patina intact, dirt dissolved, oxidation diminished. Olive oil works fine (but very slowly) on copper, bronze and oxydized brass. It does not do anything with gold, silver and nickel. Use lukewarm water instead to dissolve dirt on such coins and dry well.

The greater danger is olive oil with additives, especially lemon juice. This is sold mainly in North America, but it could have made its way elsewhere. For information on origin and ingredients, consult the small letters on the label. Don't trust brand names, e.g. Bertolli uses mainly Spanish and Portuguese, not Italian oil. Using first press oil (virgin, extra virgin) is not necessary.

Peter
An unidentified coin is a piece of metal. An identified coin is a piece of history.

Offline Rishabh Jain

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Re: Is Olive Oil safe for all metals?
« Reply #2 on: April 23, 2013, 01:46:25 PM »
So how do you suggest I clean my silver coin which has turned black on the parts where there is nothing written?
I would like to buy the Bull Anna series.

I will also buy single coins of this series.

Please message me with your price and an image of the coin/coins.

Offline Figleaf

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Re: Is Olive Oil safe for all metals?
« Reply #3 on: April 23, 2013, 01:58:21 PM »
If the black is dirt, use water. If need be, boil the coin, then drop it in cold water and use a wooden toothpick to widen the cracks. If it is oxidation (hard, somewhat shiny, thin layer) and it doesn't hide any detail, I would suggest not to take it off. Silver oxide prevents further oxidation. If by chance you succeed in taking it off, you will be left with an ugly rough spot that should have been smooth. If you don't like the oxide, sell the coin and buy another one.

Peter
An unidentified coin is a piece of metal. An identified coin is a piece of history.

Offline Rishabh Jain

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Re: Is Olive Oil safe for all metals?
« Reply #4 on: April 24, 2013, 02:43:39 PM »
I cleaned my silver coin. :)

I forgot to take a picture before cleaning but I found the picture of a coin on google to show how dirty my coin was.

BEFORE



AFTER

« Last Edit: April 24, 2013, 03:29:51 PM by Rishabh Jain »
I would like to buy the Bull Anna series.

I will also buy single coins of this series.

Please message me with your price and an image of the coin/coins.

Offline ChrisHagen

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Re: Is Olive Oil safe for all metals?
« Reply #5 on: July 05, 2013, 05:07:17 AM »
That is terrible. You made the coin really ugly. Always leave the patina on for coins like that. Only clean coins that are encrusted in dirt. You ruined your coin and it is now practically worthless. Collectors will not buy damaged coins. A cleaned coin is a damaged coin.

akona20

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Re: Is Olive Oil safe for all metals?
« Reply #6 on: July 05, 2013, 05:16:12 AM »
Hi Chris,

There is a like in India for cleaned coins. And this goes for almost all coins. Given that this coin is over 100 years old and is therefore trade restricted there is at this time no real harm.

Offline ChrisHagen

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Re: Is Olive Oil safe for all metals?
« Reply #7 on: July 05, 2013, 09:48:39 AM »
Hi,
Thanks a lot for the information. I did not know that there was a cleaned coin market specific to India!

I do apologize about my rather harsh wording in my post.

Offline Coinsforever

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Re: Is Olive Oil safe for all metals?
« Reply #8 on: July 05, 2013, 10:14:00 AM »
I think as Indian Numismatics market become more mature with awareness among lot of  collectors .

Cleaned coin market will not exist.

However it is again a matter of individual perspectives .


Cheers ;D

Every experience, good or bad, is a priceless collector's item.



http://knowledge-numismatics.blogspot.in/

Offline Kopper Ken

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Re: Is Olive Oil safe for all metals?
« Reply #9 on: July 05, 2013, 10:36:46 PM »
I soak my coins in acetone or turpentine to get basic dirt off that is not water soluable.  It does no harm to the patina.  I do use Olive oil, monitoring it periodically and if verdigras is present (green stuff), I'll use a cotton swab to gently coax it off.  Leaving the verdigras on a copper coin is ultimitely detrimental to the coin.  I use time tested conservation techniques.  I do not consider this cleaning a coin.

KK

Offline dheer

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Re: Is Olive Oil safe for all metals?
« Reply #10 on: July 06, 2013, 09:01:33 AM »
I did not know that there was a cleaned coin market specific to India!


There is no cleaned coin market in India ... there were older generation coin collectors by far few ... however in recent times say a decade or so, quite a few youngsters have taken to coin collecting ... hence the preference is to have coins that look nice ... with quite a few olders coins not available in good grades, Indian dealers also indulge in cleaning coins and bumping up the price ... for a novice collectors a shining coin is more attractive ...

so yes quite a few collectors like cleaned coins ... agree there is a difference between a coin cleaned for conservation and harshly cleaned ... it would take a while for the market to mature and appreciate the real beauty of the old coins ...
http://coinsofrepublicindia.blogspot.in
A guide on Republic India Coins & Currencies

akona20

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Re: Is Olive Oil safe for all metals?
« Reply #11 on: July 06, 2013, 09:13:00 AM »
For those who are attending next Sunday night this subject will be discussed.

Offline ChrisHagen

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Re: Is Olive Oil safe for all metals?
« Reply #12 on: July 06, 2013, 09:14:28 AM »
When you get a crusty coin from a "dirty" lot of uncleaned coins, of course you gotta clean them. But that is different from cleaning a modern coin like that one, a 2 anna from 1908. It just doesn't make sense. There is no dirt on the coin, so you can't really "clean" it. You can only polish it so as to remove the natural toning, making the coin look like it just left the factory. It looks unnatural and fake at best, repulsive at worst.

I have a hard time believing that any seller would polish such a coin and bump up the price. It just can't happen. A coin dealer will be experienced enough to know that the coin would lose its value. Also somebody working with coins as their job probably likes coins. Who would somebody who likes coins take a beautiful piece and turn it into something that looks like a modern counterfeit?

akona20

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Re: Is Olive Oil safe for all metals?
« Reply #13 on: July 06, 2013, 09:32:56 AM »
Well firstly we know that grading services in America also offer cleaning services that include among other things the manipulation of coins that have suffered PVC damage. So let us not get too starry eyed about what is right or wrong.
parts of the coin market in any area is unsophisticated. dheer knows the coin scene in India very well and his comments reflect, absolutely, the current status in India (and a few other areas).

So saying it can't happen is incorrect, it does and will continue until education corrects the market. However there may end up a separate market in India.

Frankly I am personally sick and tired of seeing the manipulated finish on many expensive American coins sold in America. Each to their own.

Offline asm

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Re: Is Olive Oil safe for all metals?
« Reply #14 on: July 06, 2013, 09:33:50 AM »
I think we should use discretion. I am all for washing old Hand struck coins, most of which come out of the earth.Some have to be cleaned so that they could be read and attributed. In that case, there is no choice. I agree that cleaning of modern coins should be avoided unless they too have come out from the earth and have chemicals (considering the huge pollution in Indian condition today) on them. As for coins with patina or natural toning, I love them as they are. 

Amit
"It Is Better To Light A Candle Than To Curse The Darkness"