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Cleaning coins for beginners

NumisdocTips & tools

Written on February 5, 2019
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About cleaning your coins

Cleaning coins may be a very attractive issue, especially for those who have just started the numismatic hobby. However, this can be such a bad idea, as it may present serious deterioration hazards. This article's purpose is to instruct this first-time collectors how to proceed when they acquire an apparently dirty coin.

Step 1

First of all, you should make a thorough analysis to evaluate if the coin really should be cleaned. This might be hard and numismatic experts never reached a consent about it. Anyway, most collectors prefer their coins untouched.
Searching the internet for photos of the coin is a good idea because you can picture how the coin should be like in good conditions. If you have doubts, asking a numismatic expert might help a lot.

Common mistakes on evaluating

  1. "The cleaner the better"
    It's frequently wrong! Most of times, old coins have a higher value in their natural state. Cleaning these coins will probably lower their rating, even though it looks better to you.
  2. Patina and rust are not the same
    Although they seem to be the same, there's a huge difference! While the rust may spoil the metal, the patina is beneficial to it, because it creates a layer that protects from...rust. Furthermore, patina can also be a valuable charm, because it tells the story behind your coin, such as the age and the place where it has been before you get it.

     

Patina vs. Rust

Step 2

Now that you are sure that your coin can be cleaned, you should be aware of how to proceed. The method you should use depends on the metal your coin is made of.

The following instructions may be useful:

Advisable methods to all coins

  1. Use running water in tepid temperature to remove light stains and dust.
  2. For heavier stains, use a magnifying glass to see the exact spot and a soft stick to remove (like a soaked toothpick, for instance).

Never rub the stick or any metal against the coin surface, as it may cause definitive damage.


  3. Let the coin dry in the sun or gingerly pat it with a soft cloth.

Copper and bronze coins

  1. Using vinegar or lemon juice: in a cup, add 3 spoons of vinegar or lemon juice and 1 spoon of salt. Drown your coin in the mix for a few minutes and wash it with running water.
  2. Using ketchup: spread ketchup all over the coin's surface and rub it with your fingers. Wash it with running water.

You must be aware that these methods won't give your coin its natural shine.


A coin in three different states: dirty, new and clean


Silver and nickel-brass coins

  1. Make a paste using 50% of hot water and 50% of baking soda. Rub it on the coin using your fingers and wash it with water.
  2. Using toothpaste: rub the toothpaste against the coin, then wash it.

Nickel and copper-nickel coins

  1. Use the first method of silver coins.
  2. Using lemon juice or vinegar: Drown the coin in lemon juice or vinegar and let it there for half an hour, then wash it.

Aluminium and aluminium-bronze coins

Use lemon juice or vinegar the same way you do with nickel coins.

Common mistakes on cleaning the coins

  1. Rubbing the coin.
    If you see an encrusted stain, don't try to remove it by force. Rubbing things against it may scratch the metal, which can't be fixed. In this case, the best to do is to accept it or to look for a professional.
  2. Using home cleaning products
    Products like bleach, detergent or wax may be very harmful to metal, as it may cause a series of damages, including corrosion. The best product to use is mild soap.

Step 3

Whether you choose to clean your coins or not, you may want to protect it from future damages. Here you will find some tips to avoid stains, tarnish, scratches and corrosion.

  1. Never store coins made of different metals together, as they may react and oxidize.
  2. Don't touch the coin with bare hands. Our hands are always dirty with natural oils and sweat, which may stain and rust the metal.
  3. Don't use PVC packs because it will react with the coin over the time creating a thick, green, harmful layer on it.
  4. A safe method to store and protect your collection is to use cardboard holders or a coin album.