Knowing how to clean coins is as useful for experienced collectors as it is for newbies. Cleaning the coins can make the images on both sides clearer and remove dirt and stains that have accumulated over the years or decades. However, if you do it the wrong way, you risk damaging and devaluing them irreparably, so much so that in many cases it is better not to clean them at all or just use a mild soap.
Steps
Method 1 of 3: Taking Care of Your Valuable Coins
Step 1. Leave the old coins as they are
While it may seem counterintuitive, the best thing to do in the case of a dirty coin is to simply leave it alone. If a coin is in good condition with only a few stains or imperfections on the faces, it will be worth more to a collector than if you clean it.
Almost all types of cleaners will substantially reduce the value of the coins, especially if one or both faces are damaged during the operation
Step 2. Have an expert analyze the ancient coins
If you are not practical, but you wonder if your ancient coins are worth anything, take them to an expert before cleaning them, so he can confirm if it is necessary to have them cleaned; if they are rare or valuable it is very likely that they will tell you not to clean them.
A numismatist, i.e. a coin (and banknote) expert, will also be able to give you an estimate of the value of your coin: the more it is worth, the less reasons you have to clean it
Step 3. Clean only low-value or very dirty coins
If you have coins that are worth little and you don't intend to collect or sell them to a collector, you can clean them for purely cosmetic reasons. Furthermore, it is up to you to decide whether or not to clean particularly dirty coins: if a coin is so blackened or stained that no images can be seen, you can consider whether to take the risk of cleaning it.
If you are in doubt about the value of a coin, if it needs to be cleaned or if you need to keep it in a collection, always take it to an expert before trying to clean it - it would be a shame to find that you have halved the value of a rare coin by cleaning it
Method 2 of 3: Practice Non-Destructive Cleaning
Step 1. Never clean your coins with abrasive or acidic substances
While abrasive products are often advertised on TV or in stores as effective in cleaning coins, there is actually no need to use them, because the acidic components of certain cleaners remove some of the material that covers the surface of the coin during cleaning. Even if the coin looks cleaner and brighter, it will get damaged and lose its value.
Likewise, you should never rub or scrape coins to remove stains or blackened parts: products such as steel wool or wire brushes will damage them irreversibly and make them lose their value
Step 2. Clean the ancient coins with water
Water is the only substance that allows you to clean the coins without risking damaging the surface and devaluing them. Take the coin from the sides and run a light stream of warm distilled water over it. Turn the coin on itself to wet the other side as well, then pat it gently with a soft cotton cloth: in this way you will remove the dirt on the surface without damaging it.
If you live in the city, tap water is most likely chlorinated. Chlorine is a chemical element that causes discoloration of coins: to avoid this inconvenience, you should buy distilled water in a supermarket or use that of the purifier to clean your coins
Step 3. Clean the ancient coins in a mild soapy solution
If distilled water proves ineffective in properly cleaning the surface of a dirty or encrusted coin, the only non-harmful option available is to use a mild soap and water solution. Pour a small amount of mild liquid soap into a large bowl, then fill it with warm distilled water, take the coin from the sides and shake it a little in the soapy solution; then rinse it under distilled water and pat it dry with a clean cloth.
Do not use dish detergent to clean coins, it is too strong and abrasive; Instead, use a light, gentle cleanser such as ordinary hand soap
Method 3 of 3: Cleaning Particular Specimens of Ancient Coins
Step 1. Scrape the old pennies with ketchup
To clean a copper penny, squeeze a small amount of ketchup on both sides of the coin; holding it firmly on the sides, gently scrub the flat surfaces with a clean brush: the salt and vinegar contained in the ketchup will remove oxidation from the penny. Once this is done, rinse the clean coin under distilled water and pat it dry with a clean cloth.
- The best results with this method are obtained on pennies minted before 1982, because genuine copper was used; pennies minted after 1982, on the other hand, contain zinc, which cannot be cleaned with ketchup.
- Be aware that ketchup is slightly acidic, so it may decrease the penny value.
Step 2. Clean the old silver coins with baking soda
Start by rinsing the coin with distilled water, then hold it firmly on the sides; apply a small amount of baking soda on both sides using your fingers or with the help of a clean toothbrush and scrub gently: the baking soda will remove stains and blackened parts from the surface of the coin. Rinse it again with distilled water and pat it dry with a clean cloth.
This procedure is especially effective on very old silver coins, while it will give less satisfactory results on more modern ones, which contain less authentic silver (or do not contain any at all)
Step 3. Clean the ancient coins with vinegar
White wine vinegar is a common cleaning agent that many use to clean metals, including jewelry. To clean an antique coin with vinegar, pour 250 ml of it into a glass or bowl, then gently dip the coin and soak it on the bottom for a few minutes; then take it from the sides, take it out of the vinegar and rinse it with distilled water.
- If the coin is still stained or dirty, try brushing it gently with a soft toothbrush, but being careful not to scratch the surface.
- If, after a few minutes, the coin no longer looks clean, put it back in the vinegar and leave it for a few hours. It may be necessary to leave very dirty old coins to soak in vinegar even overnight.
