Author Topic: Harm to coins  (Read 5584 times)

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Offline $$

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Harm to coins
« on: August 25, 2011, 05:42:52 AM »
Dear All

Need help, suggestion and view.

1) Is it ok to clean the cu ni coin with water. (Exp: I have cleaned and the coin turned reddish some of the part of coin.
2) Should we clean the coin with chemical ?
3) How do we clean copper coin to remove green partical stick to it ?
4) By cleanning with water or other liquid the coin looses it original touch or value.
5) Why the coin turns black in colour ?

Thanks for help, suggestion in advance

Samir
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Offline asm

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Re: Harm to coins
« Reply #1 on: August 25, 2011, 08:02:11 AM »
See this board for details on coin coservation and cleaning.

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

Offline Figleaf

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Re: Harm to coins
« Reply #2 on: August 25, 2011, 03:15:34 PM »
copper-nickel is extremely difficult to clean. Much depends on the dirt. If it is mud, dissolving it with water and drying well will help. If it is fatty, soap will work wonders. If it is oxydation, look for another coin. You will not be able to remove it without damaging the coin. If it is something else, try remove it with your nails.

Copper oxydation can be removed safely. My favourite method is soaking it in olive oil and attacking the oxydation with a wooden tooth pick every two weeks or so. This can take months, but it is perfectly safe.

In principle, use chemical cleaners only when you know exactly what you are doing. Many chemicals will damage the coin. One extremely bad example is Cilit Bang, which can ruin any coin. It will spectacularly turn the "nordic gold" used in euro coins into a horrid pink.

Coins turned black may be because of treatment with the wrong chemical, handling with people who also handle acids (fish mongers and vegetable sellers!), but there are many other possibilities, like chemical treatment at the mint, lacquer (used by coin collectors 100 years ago) and heat.

When treated with water or water and soap, only copper and bronze coins change colour, (provided the coin is dried well.) Discoloured coins can be repaired by keeping them in polluted air for a long time, e.g. in a window looking out on a street.
An unidentified coin is a piece of metal. An identified coin is a piece of history.

Offline The Oracle

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Re: Harm to coins
« Reply #3 on: August 25, 2011, 07:53:13 PM »
Dear All

Need help, suggestion and view.

1) Is it ok to clean the cu ni coin with water. (Exp: I have cleaned and the coin turned reddish some of the part of coin.
2) Should we clean the coin with chemical ?
3) How do we clean copper coin to remove green partical stick to it ?
4) By cleanning with water or other liquid the coin looses it original touch or value.
5) Why the coin turns black in colour ?

Thanks for help, suggestion in advance

Samir

coin collecting 101 dont clean your coins

Offline $$

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Re: Harm to coins
« Reply #4 on: August 26, 2011, 05:50:49 AM »
Thanks a ton sir

"Thanks" word stand smaller in front of you all experts and do not have other word than this.

One point i missed in that was,

A) Can i laminate my coins ?

B) Keep it in plastic box is safe ?

Samir

copper-nickel is extremely difficult to clean. Much depends on the dirt. If it is mud, dissolving it with water and drying well will help. If it is fatty, soap will work wonders. If it is oxydation, look for another coin. You will not be able to remove it without damaging the coin. If it is something else, try remove it with your nails.

Copper oxydation can be removed safely. My favourite method is soaking it in olive oil and attacking the oxydation with a wooden tooth pick every two weeks or so. This can take months, but it is perfectly safe.

In principle, use chemical cleaners only when you know exactly what you are doing. Many chemicals will damage the coin. One extremely bad example is Cilit Bang, which can ruin any coin. It will spectacularly turn the "nordic gold" used in euro coins into a horrid pink.

Coins turned black may be because of treatment with the wrong chemical, handling with people who also handle acids (fish mongers and vegetable sellers!), but there are many other possibilities, like chemical treatment at the mint, lacquer (used by coin collectors 100 years ago) and heat.

When treated with water or water and soap, only copper and bronze coins change colour, (provided the coin is dried well.) Discoloured coins can be repaired by keeping them in polluted air for a long time, e.g. in a window looking out on a street.
S
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     S

Offline Figleaf

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Re: Harm to coins
« Reply #5 on: August 26, 2011, 06:55:06 AM »
Not sure what you mean by "laminate". In general, it is not a good idea to put any kind of coating on your coins. A century ago, some numismatists would put lacquer on their coins. It got opaque, brittle and generally ruined the coins.

Plastic of all kinds can be either safe or unsafe, depending on the ingredients used to make the plastic. It is be to wait and see. Often, the first to be affected by bad plastic are large size, new copper-nickel coins. I they lose their shine and develop a smelly grey coat you can wipe off, all your coins must be cleaned by wiping. Copper and silver will turn green at the high points. This effect may also occur on coins you have recently bought if they were kept in bad plastic.

Paper and cotton-wool will ruin coins. Young wood and painted good is no good either.

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

Offline Md. Shariful Islam

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Re: Harm to coins
« Reply #6 on: August 26, 2011, 07:13:45 AM »
coin collecting 101 dont clean your coins

Often we get desperate in cleaning our coins. 'uncleaned coins are better than harmed or destroyed coins'. Sometimes patina on coins adds value to coins. If we have a plan to sale coins, then cleaning will reduce value. So, think before you leap. One more thing, don't be harsh on your kids. Be soft and gentle. Remove dirts only, don't scratch on their skins and flesh.

Islam

Offline asm

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Re: Harm to coins
« Reply #7 on: August 26, 2011, 07:16:29 AM »
Not sure what you mean by "laminate". ..........

A coating with a plastic sheet with heat. Generally used to preserve paper documents. It shrinkfits on the coins due to heat. Would be difficult to remove if properly done...... Never tried it though the thoughts did occur many times when I was still not aware of how to store coins........ i do remember Barry and Oesho advising leaving the coins in trays....... the best way where you can feel the coin in hand..... study it, weigh it, re-read it in case there is an error pointed out...... but not in Indian conditions with heat, moisture, pollutants and sweat........ as well as theft.......

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

Offline Md. Shariful Islam

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Re: Harm to coins
« Reply #8 on: August 26, 2011, 07:23:34 AM »
....... the best way where you can feel the coin in hand.....

Amit

This is really important. Still no way that I could think. Another problem of leaving the coins nude is that risks scratch on them.

Islam