How do you clean up old collector’s coins?

Are you really thinking of cleaning up an old coin? You should read the whole article before doing so, you are likely to find more than one surprise.

In this article I clarify the main doubts about cleaning collectible coins , and I will share with you some methods you can follow if you think it is a good idea to clean your pieces.

I warn you that the ideas that I summarize in this text go against what some journalists and media that have no idea about numismatics publish. So I hope you can make the most of the content I share.

Is it advisable to clean an old coin?

It is NOT recommended to clean an old coin in most cases.

Don’t be surprised and try to answer the following question:

Do you think there is anyone who has an old coin in their possession and does not want to clean it up to make it look new, shiny, free of dirt or rust? Well, I do know them, most of the collectors of antique coins.

Cleaning an antique coin is a very delicate process that can affect it. In some cases it can result in the numismatic piece losing all its value.

If you have a coin that you suspect has a lot of value, but you are not sure, it is preferable that under no circumstances should you think of cleaning it. Only in some situations, and following the methods I will tell you later, is it advisable to clean an old coin.

If you are not interested in preserving the value of the coin, then you could clean it.

Otherwise, learn from coin collectors that most of the time they don’t want to know anything about pieces with obvious signs of having been cleaned. Instead, collectors and numismatic professionals prefer to see the discoloration of time on the metal, or the green or brown patinas.

The bluish, greenish or brown tones of the patinas are the result of the antiquity of the coin, and no one interested in preserving the value of an old coin would ever think of removing them.

Even new collectible coins (such as 2 Euro coins) should not be cleaned either, since the brightness of the newly minted metal is lost once the coin enters into circulation and is not recovered in the same way.

How does the cleaning of an old coin affect its value?

From a numismatic point of view, and for most collectors who know about the subject, cleaning an antique coin is a mistake that significantly affects it.

In other words…

It is a mistake to clean the old coins. A mistake that can have serious consequences.

Deeply cleaning an antique coin or applying chemicals, such as ammonia, can bring out the shine, but will remove the patina, cores and other elements that tell the story of the numismatic pieces.

One question I see a lot on the internet is:

Should an old coin be cleaned if it has patina?

The answer is quite simple. Most likely you should not clean the patina of your coin, as it is possible to damage it and in that case it would lose all its collectible or commercial value.

Collectors don’t like coins that show signs of cleanliness such as small scratches on surfaces, or a shine that is not justified according to the history of the coin.

When can old coins be cleaned?

Without fear of contradiction, I would like to tell you about some situations in which it is advisable to clean the old coins in your possession.

These situations are:

• When the old coin accumulates a lot of dirt due to the passage of time and the passing of time from hand to hand. Mainly on old coins that were in circulation.
• When the coin has stains that have been produced by external agents or substances. This topic does not include the natural stains produced by different metals over time.
• When the old coins are oxidizing. It is something that commonly occurs in silver coins, and in these cases the coin is cleaned to save it from corrosion.
• When the coin has impurities adhered to the surface, but we notice that they can be removed without applying very rough cleaning processes.

There is another situation in which it is completely reasonable to clean the ancient coins, and that is when you want to analyze them from the archaeological point of view. However, you must take into account that in these cases the economic and collectible value of the piece will most likely be lost.

So…

Process for cleaning an old coin

If you insist on cleaning an old coin, let’s talk about the best known methods that many people use on their pieces.

The most common methods are:

• Cleaning antique coins with Lemon
• Cleaning of old coins with Vinegar
• Cleaning of old coins with Neutral Soap

Let’s review each of the methods listed for cleaning antique collectibles.

Cleaning of old coins with Lemon

On the internet there are many pages that advise cleaning the coins with lemon to extract all the shine from the piece. They promise that after “leaving an old coin as new” it will gain a lot of value and the opposite actually happens.

As I told you before.

Most of the times when coins are subjected to an extreme cleaning process they lose all their numismatic value and therefore the interest of collectors.

Lemon juice has a high level of acidity. When a coin is placed for several minutes the acid will release the accumulated rust leaving it shiny. It is a method used to clean copper coins, but it affects the value of the cleaned piece.

Cleaning Old Coins with Vinegar

Another product often used to clean coins is vinegar. You can find many tutorials on the internet that explain how to perform this type of cleaning of old coins.

As with the previous method, we recommend you to be careful if you don’t want to leave the coin of collection without value.

The method of cleaning old coins with vinegar is more or less like this:

• Place the coin under the cold water tap and allow the pressure to naturally remove the dirt and incrustations.
• Place the coin in a container with vinegar and hot water in equal parts.
• Wait between 10 minutes and half an hour.
• Take out the coin and rinse it with cold water so as not to leave traces of the vinegar on the surface.
• Use a cloth to dry the coins. Never use cotton or paper, because these materials will fall apart and make the coin dirty again.
• Is it advisable to clean old coins with vinegar?

The answer is NO if you want them to keep their commercial or collectible value.

If you plan to sell the coin do not clean it first, and if you want to collect really valuable coins do not buy those that have been cleaned.

Cleaning old coins with Neutral Soap

Now the method is recommended by prominent collectors such as Ruiz Calleja in his numismatic blog. This method basically consists of cleaning the coins with neutral soap, although the author comments that he has never cleaned a coin and does not intend to do so either.

The method is like this:

• Place the coin under the cold water tap and allow the pressure to naturally remove the dirt and incrustations.
• Add neutral soap with your fingers and rub your fingers very gently.
• You can go over the edges with a cotton bud, but be careful not to scratch them.
• Clean the soap with running water, under the tap.
• Dry with a cloth, never with cotton or kitchen paper.
• This is the only coin cleaning method that can be done by non-experts.

Anyway, if you have doubts about the possible damage you can do to the piece, affecting its value, it is better not to do any cleaning.

Recommendations for cleaning coin collections

Now I will share some general recommendations that it is important for you to follow, regardless of the method you choose.

First recommendation: Never use liquid or powdered chemicals to clean or polish an old coin. Chemicals often react with the precious metals in coins to cause changes or damage that affect their value.

Second recommendation: Only use cloths or towels to dry the coins after cleaning with neutral soap. You should never use brushes, no matter how soft, to remove dirt.

NOTE: Regarding brushes, it is only valid to use them to remove the soil from the unburied coins. The correct brush is a very specific fiberglass brush.

Third recommendation: Don’t be obsessed with the taps and skids. Many times they persist after a cleaning and are a consequence of the history of the ancient coin. Therefore, eliminating them with very aggressive methods could devalue the coins.

Fourth recommendation: On old copper or bronze coins, olive oil can be used to clean them. This product usually removes the impurities and dirt that are then eliminated by rinsing the coin with abundant water.

Fifth recommendation: Store your coins in places free of humidity or sudden changes in temperature that impact the metal. This prevents or slows down the normal process of oxidation or wear of numismatic parts.

Sixth recommendation: Never, ever use detergents or polish to clean old coins. These products have very strong chemicals that will surely affect the state of conservation of the pieces.

Do you want to clean your old coins?

I would love to know if you have the same idea now that you know the implications, methods and recommendations for cleaning old coins.

You may have changed your mind, and think it’s better not to clean the coins, or leave this process to a professional. In this case, my article would have served its purpose and I would be very happy.

The only thing left to do is to share this article on your social networks so that other people can avoid making a mistake that costs them dearly.