How can you wash a coin. How To Clean Coins - The Best Methods From Experienced Numismatists. Ways to clean copper coins from rust and oxidation

It is difficult to find a numismatist who has never faced the problem associated with the appearance of oxides and rust on collectible items. Therefore, every collector asks the question of how and with what to clean coins at home. In fact, caring for coins requires adherence to a number of rules, especially when it comes to cleaning old specimens of high historical value.

Cleaning coins with soapy water

Rules

Before choosing a coin cleaner, you should pay attention to the alloy from which the specimen is made, because each metal can react differently to the same substance that is part of the cleaning agent. Still, there are tools that can spoil any coin. For example, a powder with abrasive particles that leave scratches on its surface can be detrimental to the state of the metal.
It is not recommended to clean copper coins at home with concentrated acids, for example, hydrochloric or sulfuric acid.
If the coin is proofed, then it cannot be cleaned by any means. It is enough to regularly wipe the specimen with microfiber.
Before cleaning old coins, you should pay attention to the peculiarities of their patina. If the layer of plaque is uniform, and the images on the coin are clearly visualized, then cleaning such a specimen is not worth it, since removing the patina may result in the loss of the noble appearance of the coin and a decrease in its value.
Before using any cleaning product, you should test it on less valuable collectibles. An unsuccessful cleaning experiment can end up negating the value of expensive items.

Copper-Nickel Coins: Cleaning

Coins, consisting of an alloy of nickel and copper, were made from 1931 to 1935 in the USSR. On such specimens, brown-red oxides appear, which are rather difficult to remove. So how do you clean nickel and copper coins?

1) Electrolysis method: its essence lies in the supply of electric current to the electrolyte, which is a salty aqueous solution. Important: by choosing this method of caring for coins, you should provide protection against electric shock, as well as protection against electrolyte ingress on the mucous membranes! To clean coins by electrolysis, you should prepare a power supply with a voltage of up to 18 volts (this can be a power adapter from an old phone). Its plugs must be cut off, the wires must be divided into 2 parts, and the insulation must be removed from the ends of the wires. Copper veins are twisted and soldered to metal crocodile clips. After preparing the adapter, you can start preparing the electrolyte: take 1 teaspoon of salt and dissolve it in a glass of cold water (the prepared liquid is poured into a plastic bath).

Cleaning a coin by electrolysis

After the work done, it is necessary to determine which wire will be the cathode and which will be the anode. To do this, a simple test is carried out: a metal spoon is immersed in a container with a solution and one clamp is attached to it, and the other is connected to a coin. Before starting the adapter, make sure that the coin and spoon are not in contact, otherwise the adapter may break. If there is a hiss near the spoon after turning on the equipment, the clamps must be reversed.

The wires with the "-" sign are connected to the coin, the positive wire to the metal spoon. The coin is left in the bath until it is completely cleaned. Electric current through the metal will push out rust and dirt.

2) Trilon-B: This product is widely used for cleaning nickel-copper coins, so it can be used to clean old coins. A solution consisting of 1 part of the product and ten parts of water is prepared from Trilon-B. Then a coin is immersed in such a solution and its cleaning is monitored. Finish cleaning by rinsing the coin in clean water and drying it.

3) You can clean the coin in an unusual way: take tobacco ash and water, after which a thick gruel is prepared from these two components, which is applied to the coin. After 20 minutes, the ash is rubbed into the copy, after which it is washed off with water, and the coin is dried.

Copper-nickel coins can be damaged by:

Vinegar: This cleaner is often used to clean coins, but can be destructive for copper and nickel. Acetic acid gives coins an uncharacteristic pink color. In addition, the minting becomes fuzzy, due to which the value of the coin decreases.
It is known that patina is effectively cleaned from metal with hydrochloric acid. Its household counterpart is a tool for cleaning plumbing fixtures from corrosion deposits - "Toilet duck", because the tool contains hydrochloric acid. But it is not suitable for cleaning nickel and copper coins, since hydrochloric acid can turn a valuable specimen into a shiny metal disc without any images.
Do not clean coins of the period of the USSR with GOI paste, as this tool contains abrasives that can disrupt the images on the coin and make it unnaturally shiny.

How to clean old copper coins?

How and how to clean copper coins:

Soap: if copper coins have insignificant contamination, it is enough to use a soap solution. It is necessary to immerse coins in it for several hours, then take them out, rinse in water and dry. If collectibles require more cleaning, you can use baby soap to make a paste. To do this, finely grate a bar of soap and combine with water so that a thick gruel is obtained, which should then be completely covered with coins. The gruel is left on the coins for 2-3 days, after which it is washed off.
Vinegar: For pure copper coins, this agent is approved for use. It is enough to fill the coins with a bite and constantly monitor the degree of their cleaning. It is important not to overdo the specimens in vinegar, otherwise the metal may deteriorate. For cleaning coins, you can also prepare a "vinegar dough" consisting of wheat flour and vinegar taken in equal parts. Coins are covered with "dough", wait for it to dry, and then cleaned off with a soft brush.
Ammonium: it is used in extreme cases at the risk of the numismatist, when the coin is densely covered with oxides that cover the image. You just need to put the coin in ammonia and take it out every 20 minutes to brush it with a toothbrush. The procedure is performed until the desired effect is achieved.
Self-made cleaning product: consists of one gram of oxalic acid, five milliliters of ethyl, four milliliters of turpentine and a milliliter of water. All ingredients are mixed, mixed thoroughly, and then the resulting product is applied to a cotton swab. They carefully wipe the coin with it, and then wipe it dry with a microfiber.
Calgon: This product effectively dissolves rust deposits. Calgon is combined with water in a ratio of 1: 5, then the solution is brought to a temperature of 60 degrees. Coins are dipped into the resulting product and wait for rust to separate from them.
Olive oil: This cleaning of coins at home takes several months, but at the same time, olive oil is absolutely safe for copper. All you need to do is take olive oil, pour it into a bowl and completely immerse the coins in it. After 60 days, the specimens need to be removed and cleaned with a soft brush. After that, the oil must be renewed and the coins must be immersed in them again. Actions are performed until the final disappearance of contamination.
Vaseline: This oil can be used to clean non-essential copper coins. Fill a small saucepan with Vaseline oil, dip coins into it, close everything with a lid and put the vessel on very low heat. After the oil boils, the fire must be turned off, and after another 10 minutes, take out the copies and gently brush them with a brush.

Ammonia

Also, copper coins can be cleaned with "Trilon-B" and the electrolysis method.

A universal method of cleaning coins from dirt and oxides is the use of ultrasound. For this purpose, an ultrasonic bath is purchased - a portable equipment that acts on the items to be cleaned using ultrasound. Thanks to this equipment, you can clean not only coins, but also jewelry. The ultrasonic cleaner is battery operated. How to clear coins in it:

A coin is placed in a removable tray container.
Pour water so that it completely covers the specimen.
The bath is turned on and the process of cleaning the coin is monitored.

If the coin is expensive and valuable, then it is recommended to entrust its cleaning to an expert who probably knows how to properly care for valuable specimens.

Over the years, coins accumulate dirt, microbes and various plaque, which impairs the shine of the metal and reduces its attractiveness. It is for this reason that you may be tempted to clean the coins and give them their original appearance. We warn you that cleaning collectible, trial, not put into circulation coins or samples of precious metals may affect their value, and in case of damage, the price may drop to the cost of the material from which they are made.

Steps

Washing coins

Keep the coin under warm water. A stream of warm tap water can remove the top layer of dirt. You do not need any additional devices, the pressure of water from the tap will be quite enough. Leave the coin under running water for a couple of minutes. Then place the coins on a paper towel or cloth.

Place coins in a solution of water and dishwashing detergent. Make the solution in a small bowl using warm water and dishwashing liquid, and then dip the coins in the solution one at a time. Pinch the coin between your thumb and forefinger, then gently wipe off any plaque from both sides of the coin. It will become cleaner before your very eyes.

Heavily soiled coins can be left in the solution for a while.
Non-abrasive liquid solvents, consisting of distilled water and a mild detergent, have sufficient cleaning power to remove dirt from coins and do not contain acids that can damage metal.

Scrub the coins with a soft toothbrush or paper towel. Scrub the coins with a brush while they are in the soapy solution. Clean until the sides of the coin are shiny again. Wash the coin frequently in water to avoid visible scratches. This cleaning method can damage valuable or antique coins and reduce their value.
- After brushing, coins must be rinsed thoroughly.
- Don't rub the coin too hard. Focus on a small area and work with gentle strokes.
Dry the coins with a towel. Wipe each coin with a towel and place them in a dry place. There should be no moisture on the coins, otherwise they will start to deteriorate over time. Your coins now look like new again.
- It is best to use a non-cotton cloth to remove the liquid.
- Simply dabbing coins with a cloth or towel will prevent micro-scratches.
Soaking coins

Make a cleanser using isopropyl alcohol and salt. These chemicals are abrasive and acidic to remove any dirt. To create a solution, add two tablespoons of table salt to a glass of over-the-counter isopropyl alcohol. Stir the solution and place coins in it. Leave the coins in the solution for two hours to a week, depending on how dirty they are.
Rinse the coins with distilled water. Tap water contains chlorine, which gradually eats away at coins. It is best to use distilled water for rinsing to completely remove all chemicals.
- Distilled water is water that has been purified from all contaminants.
- You can buy distilled water at any supermarket.
Blot the coins with a cloth and air dry. Flip the coins and repeat the steps. Do not fold coins immediately after drying to keep moisture away. Any remaining moisture will have a negative effect on the coin.
- Exposure to extreme temperatures degrades the patina of coins. Do not use heated air for drying.
- If, after getting wet, traces of cotton or dust remain on the coin, then they should be blown away without using compressed air.
Store coins at room temperature in acid-free plastic folders. Common storage materials such as paper, cardboard and some types of plastics can damage the surface of coins. Do not use containers containing polyvinyl chloride (PVC) as they are dangerous for coins. Extreme temperatures are also detrimental, so it is best to store coins at room temperature and low humidity.
- Do not store coins where they can fall (high, wobbly shelves).
- For demonstration of coins, you can use a folder for two pockets, made of lavsan (special polyester for storing coins).
Cleaning collectible coins
1. See a professional. Be sure to consult a professional appraiser before cleaning collectible coins. Cleaning collectible coins can significantly reduce their value; sometimes “tinting” or discoloration of the coin and patina on exposure to air can increase the overall value. So it's best not to clean up valuable or antique coins.
  - When handling antique coins, always hold them by the edge, not the flat sides. Grease and fingerprints can negatively affect sample cost.
  - There is a standard classification of the condition of coins, so even the smallest scratch from wiping can greatly reduce the value of a coin.

When choosing a tool for cleaning coins from rust and oxidation, you should take into account the type of metal from which they are made. Improper cleaning can damage valuable items and significantly reduce their cost. None of the alloys withstands treatment with compounds with aggressive particles - the latter leave scratches on the surface of products.

It is generally best not to try to clean copper coins to a shine. Patina - a natural finish in black or dark brown colors - protects the metal from environmental influences.

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General rules

Before you start cleaning, you should study several recommendations that will save you from common mistakes novice numismatists:

1. Do not use abrasives and aggressive compounds for processing valuable coins. They leave scratches on the surface and can ruin the pattern on the product.
2. You should not try risky methods that require a lot of experience (for example, electrolysis).
3. Do not use digestion. If the coin has a scratch, crack or traces of rust, it should not be heated - this will permanently damage the money.
4. Do not leave items in the cleaning solution for a long time. Even if the contamination is strong, it is not advisable to try to get rid of it with prolonged soaking. This will not lead to the desired result, but it can cause irreversible changes in the coating.

To prevent the metal from darkening, each valuable specimen should be kept separate from each other, avoiding their contact. If you need to get the item, then before putting it into an album or other permanent storage, the coin is washed with soapy water and dried thoroughly.

Choice of detergents

The table will help you to choose the right means with which you can launder old money.

Metal	Care features	Cleaning products	What cannot be used / done?
Bronze	Clean only from rust or other contaminants, do not remove patina	Citric acid, vinegar, "Trilon B"	Treat with sulfuric or nitric acids
Gold	Frequent cleaning is undesirable. Scratches easily on soft metal surfaces	Laundry soap	Abrasive compounds, aggressive substances, rub intensively when cleaning
Silver	Clean if the coins show signs of oxidation	Soda, ammonia, toothpaste, formic acid, hydrogen peroxide, "Trilon B", hydrochloric acid	Rub intensively
Copper	Removes rust, removing patina reduces the cost of coins	"Trilon B", hydrogen peroxide, vaseline or vegetable oil, ammonia, vinegar, distilled water, oxalic acid, sodium hexametaphosphate solution	Clean copper coins if there is no rust or other contamination on the surface, trying to get rid of the patina
Iron	Can be brushed with brass wire bristles	Weak hydrochloric acid solution	Use aggressive means
Cupronickel	It is subject to oxidation and turns black. Remove plaque with mild means	Ash, dishwashing powder	Use compounds with abrasives
Brass	Products made of copper-zinc alloy are weakly susceptible to corrosion; various means can be used to remove dirt deposits	Oxalic acid, Trilon B, Coca-Cola, soap, citric acid	Treat money with aggressive substances
Metal alloy	Bimetallic coins require gentle cleaning	"Aksidol"	Use aggressive and abrasive products

Universal remedies

There are three methods that work quite mildly. They can be used for most metals:

1. Baby soap. The bar is rubbed on a medium or coarse grater. Add some water to the shavings. It is necessary to get a thick plastic homogeneous mass. Then coins are inserted into this mixture, periodically pulled out, inspected. When dirt, rust and traces of oxide have come off, rinse with running water and remove the remaining moisture with a napkin.
2. Laundry soap. Boiling water is poured into a plastic container, soap shavings are added. Mix thoroughly. As a result, you should get a jelly-like mass. Put coins in a soapy solution, leave for 24-48 hours, depending on the degree of contamination. After this period, take out, gently clean off the remnants of dirt with a brush with soft bristles, rinse and dry. You may need to repeat the procedure more than once to completely restore the original appearance of the coin. This is the only method that works for cleaning gold coins.
3. Sour milk. At home, you can remove rust from metal money with the help of sour milk. Combine 50 ml of liquid with 100 g of vaseline oil, apply the mass on a cotton pad, treat surfaces with corrosion. Then wipe dry with a clean cloth. The acid in milk will soften the rust.

Effective ways to clean a silver cross at home

Silver

Before trying the methods listed in the table, you should try to remove plaque from silver coins in the mildest way - with soapy water. Only if it does not help, apply soda or other cleaning compounds.

Means	Cleaning method
Baking soda	A method to help cleanse silver to a shine. A small amount of water is added to the powder to form a thick paste. They put money in this mass, leave it for a few minutes. Then wipe with a sponge or cloth, rinse with water and dry
Formic acid	A 5% solution will remove oxides. Pour liquid into a glass container, put products there. Leave it on for a few minutes. If dirt remains, the acid can be heated to 50-70 ° C, applied to coins, gently cleaned with a soft brush
Ammonia and soda	Copes with green stains, dirt, oxides, blackness. Ammonia and soda are mixed to the state of gruel. Apply mass to coins, rub. Rinsed with water
Lemon acid	1 part of the powder is dissolved in 3 parts of water, placed in the solution of the coins so that the liquid completely covers them. Leave to soak for a while. Flip over to the other side periodically. Heavily contaminated areas are cleaned by rubbing with a cotton swab
Silbertuschbader	Silbertuschbader is a liquid substance used by professional restorers to clean silver with a fineness of 626 and above
Hydrochloric acid	This method is not suitable for cleaning old coins - the acid removes the patina, reducing the cost of the product. It is impossible to buy acid in its pure form, but there are household products that contain it. The liquid is diluted with water in proportions of 1 to 10, pouring into porcelain dishes. Money is put in a solution, left for 10-20 minutes, taken out and tried to clean, washed with running water. If the rust and dirt have not left the first time, they are again placed in a cup with acid. When working, it is important to observe safety rules: hydrochloric acid is a caustic and toxic substance

Copper, bronze and brass

On the surface of copper coins, under the influence of carbon dioxide, hydrogen sulfide, and water vapor contained in the air, a patina is formed. Its color can vary depending on the composition of the alloy and the age of the plaque itself from green to brown.

Antique Coin with Patina Not Requiring Cleaning

If there is no other damage to the copper product, it is not recommended to remove the patina. However, if there are signs of corrosion, the coins should be carefully cleaned. The tool is selected based on the color of the plaque.

Patina color	Means	Mode of application
Black	Vaseline or vegetable oil, alcohol	Put oil in a saucepan, put on fire. Bring to a boil, put coins in the liquid. Keep until the contamination disappears. Then they take out the coins and wipe them with a cotton pad moistened with alcohol to remove greasy marks
Black	Hydrogen peroxide	Mix 30 ml of liquid with a teaspoon of ammonia, dissolve in a glass of water. They put coins there, leave for a quarter of an hour. Then they take out and gently clean off the softened oxide with a piece of flannel cloth
Yellow and light yellow	Vinegar	Covered with a light bloom, money is placed in a container with a 10% vinegar solution. Contamination will dissolve under the influence of acid, it will be easy to remove them with a sponge
Reddish brown, cherry	Ammonia, ammonium carbonate solution	A 10-15% solution of ammonia or 5-10% solution of ammonium carbonate is poured into a container, coins are immersed there. The liquid must completely cover the product. Leave for a few minutes, then clean with a soft cloth and rinse
Whitish	Distilled water	Copper products are placed in a glass of distilled water, left for 2 days. Then remove the white patina with a soft bristled toothbrush
Black	Oxalic acid, turpentine, ethyl alcohol	1 g of acid is combined with 1 ml of water, 4 ml of turpentine and 5 ml of alcohol. Shake, moisten a cotton pad in a liquid. It is applied to the blackened surface and left for 10 minutes. Then remove the remnants of the product and dirt with a dry soft cloth
Black	Flour and vinegar	Combine the components in such proportions to make a paste. Apply the mass to the coins, leave to dry completely. Then remove the remnants of the dough with a brush or rag
Black	5-20% sodium hexametaphosphate solution	Pour the solution into a saucepan, put coins in it. Put on fire and heat the liquid, stirring constantly, to 60-80 ° C. During the process, patina and corrosion will soften and can be easily removed with a soft brush.
Black	Lemon acid	In a bowl, combine half a teaspoon of acid and 200 ml of water. They put a coin in the liquid, periodically turn it over to the other side. After a maximum of 10 minutes, remove and remove residual solution under running water. Dry thoroughly
Black	Trilon B	A 10% solution of ethylenediaminetetraacetic acid is heated to 80 ° C, stirring constantly. This is necessary for the acid to completely dissolve in the water. After the liquid is cooled, the surfaces covered with corrosion are treated with it.

For cleaning bronze and brass coins, use "Trilon B", citric acid and vinegar in the same way as described in the table. You can also use a Coca-Cola drink. A carbonated drink is poured into a flat container, contaminated products are placed on the bottom. Leave for a week, turning the coins to the other side daily. After the specified period, take out, rinse and dry. This method will help remove weak patina, it is not suitable for dealing with serious dirt.

Cupronickel

An alloy of copper and nickel is susceptible to blackening and oxidation, and to remove such contaminants from Soviet kopecks, they use:

1. Ashes. Cupronickel coin is dipped in water, then cigarette ash is immediately applied to it. Leave for 15-20 minutes, then rub the wet powder into the surface with gentle movements. Rinse with running water and wipe with a paper towel.
2. Soda and foil. The bottom of the container is covered with foil, soda is poured there. Pour boiling water over, stir. They put coins on the bottom. Covering with a lid, leave for several hours. Then washed with soapy water, removing plaque with a soft-bristled brush.

Cupronickel coin with rust

Bimetal

Coins in denominations of 10 rubles are made of 2 types of metal: the main part is made of silver or steel, and the rim is made of copper, gold or various alloys. Therefore, in order not to damage such products during cleaning, you should use products that are safe for both types of metal.

Means	Application procedure
Ammonia	A 10% ammonia solution is poured into a saucer, a coin is put there. After 10 seconds, they take it out, wipe it with a piece of cloth until it shines. If after the first treatment not all the dirt has been removed, the procedure is repeated. The main thing is not to overexpose the product in solution.
Dishwashing gel	Dissolve 30 ml of liquid in a liter of boiled warm water. Place the coins in the solution for half an hour. Remove, wipe with a piece of flannel or other soft cloth
Lemon acid	Will help remove dirt and dust. Dissolve 3 g of powder in a glass of warm water. Clutching a coin in tweezers, dip it into the solution for half a minute. Take out and polish with flannel. It may be necessary to repeat the cleaning several times.
Soda	10 g of powder is dissolved in a glass of boiling water. Coins are immersed there for a quarter of an hour. Taking out, rub
Toothpaste	Apply a white paste to dirty surfaces, remove plaque with a soft brush. Washed and dried
Vinegar	Soiled money is immersed in a 5% vinegar solution, left for a couple of hours. Rinse and wipe dry
Coca Cola	They put coins in a container of soda overnight, wash them with water in the morning and dry them on a napkin
A mixture of vinegar and citric acid, ammonia and soda	For heavily soiled coins, the following method is used. Metal dozens are washed with soap. A small amount of acid is dissolved in vinegar, the liquid is heated. Coins are immersed there for a few minutes. Then they are washed off with water, a paste of ammonia and soda is applied to the surface. Rub the mass into the coins for a few seconds with gentle movements, then rinse and dry

Citric acid and soda can also clean aluminum coins.

It is quite easy to clear the coins of the USSR. The main thing is not to use aggressive compounds. The most popular are 2 methods of processing Soviet metallic money:

1. A mixture of toothpaste, ammonia and soda. All components are mixed in equal proportions, applied to a piece of clean cloth, wipe the contaminated surfaces. Brush off the remnants of the product with a soft brush, rinse and wipe with a paper towel.
2. Citric acid. 1/2 teaspoon of the powder is dissolved in a glass of boiling water. Taking a coin in tweezers, immerse it in hot liquid for 20 seconds. Take out, rinse with cold water and wipe dry.

Money should not be soaked in a citric acid solution - prolonged exposure will destroy the coating and the metal will lose its shine.

To prevent the coins from being damaged after cleaning, you should adhere to the general rules for cleaning and use only approved products.

Over time, all coins begin to rust, and many collectors find it important to clean the coins for a presentable look.

Cleaning coins at home requires adherence to all sorts of rules.

House cleaning is simple and easy for everyone.

You can also rely on professionals to ensure that coins are cleaned from more expensive metals that are coated with oxide and require the right expertise. If you are cleaning coins yourself, you must use the best cleaning agents.

Copper

Lemon acid;
Vinegar;
Ethanol;
Electrolysis;
Soap solution;
Boiling in baking soda;
Trilon B;

Since the coins may be old, it is allowed to use the above methods, but very carefully.

If green dirt has accumulated on the coin, then the safest method is to leave the coins in kefir for three hours or soak them in soapy water using baby soap.

It also effectively removes ammonia from plaque on the coin, in time it is enough to immerse it for 30 seconds and immediately clean it with a brush. The action is repeated three times until the coin is completely cleaned.

Baking in baking soda can also provide good cleaning. Add 5 tablespoons of baking soda to 1 liter of water and boil the coins for about 30 minutes.

A fairly effective method is purification with Trilon B. The metal from the use of Trilon B does not collapse and allows you to quickly clean it from various contaminants. After this cleaning, artificial patination should be done.

Bronze

There are several ways to clean bronze coins:

Lemon acid. The coins are immersed literally for 15 minutes in 30% acid and water (3: 7).

After immersion, the coin may turn pink, but do not panic, this reaction is quite predictable between acid and bronze, so after two weeks the color will appear as before.

Laundry soap. Rub the soap on a coarse grater, add hot water (1: 8), mix. The coins are placed for about two weeks.

This is sufficient to treat the patina with alkali. If there is little dirt left, you can wipe the coin with a regular cloth. The method is used only if initially the coin did not acquire a green plaque.

Boiled oil. Bring vegetable oil to a boil, put a coin there and boil for 5 minutes over low heat.

After boiling, the metal must be rinsed and placed in ammonia.

To begin with, it is best to test this method on a less valuable coin, otherwise the more expensive one may go bad.

Use a spoon and tweezers for the hot vegetable oil treatment... Be sure to wipe the coins with a dry soft cloth or napkin.

Bimetal coins

The processing of bimetal coins is carried out very carefully so as not to damage the structure of the coin and its peculiarity in the future.

Vinegar 9%;
Whitening toothpaste.

Coins are placed in a jar, poured with vinegar in such an amount that will cover the coins.

Coins should not sit in the vinegar jar for more than two minutes.

We take out the contents and only after 10 seconds we clean it with a toothbrush with a small amount of paste without any extra effort. We wash off the particles of dirt and paste, wipe it with a napkin or dry, soft cloth.

Folk remedies for cleaning coins

There are various cleaning methods that can be used at home:

soap solution using baby or laundry soap, this method is suitable for absolutely all types of coins,
boiled vegetable oil,
aqueous solution with,
oven cleaners.

Before resorting to such actions, you need to know what metal the coin is made of or consult with professionals for the selection of a cleaning agent.

Chemicals

Chemical cleaning is a popular method for recovering coins.

It implies the use of various reagents, such as: acids, baking soda, ammonia, washing powder, toothpaste and other products... If possible, you can use a solution of hydrochloric acid with clean water without impurities.

It is enough just to put a coin in a jar of acid, and the accumulated dirt or plaque will come off it.

As the procedure is completed, you should rinse them with alkali, in order for the reaction to stop completely, dry with a regular cloth or dry napkin. A soda-based solution acts as an alkali.

Drying coins after cleaning

Then it is necessary to carry out drying in acetone, followed by ammonia after 1 hour.

For drying, it is advisable to use a thermostat, that is, a special drying cabinet, keeping coins there at temperatures up to 100 ° C for no more than 2 hours.
So that, on which there are at least some signs of bronze disease, they are immersed in a humidifying chamber.

If copper coins have an unpleasant shine, then it is possible to artificially create a patina from light to dark; it is necessary to dilute 50 g of copper sulfate and 5 g of potassium permanganate in 1 liter of liquid.

The solution is heated to 80 ° C, coins are immersed there and held until a certain color is obtained.

After drying the coins, they are covered with a protective layer, paraffin.
Another method is a solution of polybutyl methacrylate 5% in acetone, a mixture of benzene with alcohol (1: 1).
Storing expensive coins should not be in piles, but in special trays with compartments, collectible coin albums. Thus, this is how coins can lie for a long time.

Precautions When Cleaning Coins

To cleanse coins, the chemical compositions require a clear definition of the alloy from which the coin was made.

As a precaution, the coin should be cleaned of dirt, but do not thoroughly scrub off the dirt, as coins may contain abrasives that can subsequently damage the surface.

It is enough to dip the coins into the water and wash off the remaining dirt.

Coin cleaning is required to avoid re-staining. After the primary cleaning, proceed to the main one. Coins are laid out with tweezers at the bottom of the jar with the solution. Take them out after 3 minutes.

For example, bimetallic coins are cleaned with bleaching paste or detergents to remove rust. For a modern coin, acetic or citric acid is suitable, which is rubbed in with cotton pads, washed with warm water and dried.

Silver coins can be wiped with a cotton swab dipped in ammonia.

When giving preference to dry cleaning, it is important to observe all precautions and its conduct. Any coin is considered valuable and good when there is not a trace of dry cleaning on it, which is why avoid contamination and carefully store your collection, which will delight you for a long time.

Which coins cannot be cleaned?

Like all valuable coins, there are those that cannot be cleaned at home, otherwise very expensive coins may lose that part because of what they are so valuable. Let's go through the categories of coins that don't have to or shouldn't even be cleaned at home.

The types of coins that are properly cleaned and the types of means used for cleaning were analyzed.

Pay attention to whether there are chips, deep scratches or dents on the surface of the product, whether there are irregularities, since then you can only use the usual rinsing under running water.

With a soft brush, you can remove dirt and simply rinse and dry the coin. It is possible that cleaning with any reagents or abrasives will damage the item and make it unusable for collection.

Where can you go for coin cleaning?

Basically, the question of where to go to process coins appears quite often, but no one can give an exact answer to it. If a hole is formed on the coin, you can contact the jewelry workshops.

In the modern world, there are many ways to cleanse, but nowhere is it mentioned about the places where they do exactly this, so all that remains is to take matters into their own hands and use various methods to cleanse valuable coins.

In order not to subject old coins to frequent cleaning, they should be well taken care of and preserved. Store in a dry place and hide from direct sunlight.

Try to avoid touching the coins with your hands; take them by the edge. If it turned out that you took it in your hands from the front side, then wash it with soap and dry.

Proper care and respect for rare coins pleases any numismatist with their grace and beauty. Old coins are passed down from generation to generation and can bring good profits.

Storage and cleaning recommendations for novice coin collectors. Valuable coins carry their own history and, more than ever, they should not undergo chemical or mechanical processing without the inability to use these methods correctly.

If the coin is not heavily soiled, you can do with the usual washing using a soft brush. Polished coins of excellent quality and patina are not recommended for these cleaning methods.

Unskillful attempts to lead to an improved appearance, a rare coin, will definitely lead to its deterioration and the loss of the historical numismatic superiority of this subject.

It is necessary to resort to cleansing and patinating in order to improve the appearance of the coin and preserve the collection of valuable coins and to replace this specimen with a better and higher quality one.

With the most valuable coin, to resolve the issue of exchanging or replacing a coin, you can contact those who are engaged in this service, they will help you not to spoil the look of the coin and ensure the safety in the collection. If necessary, this operation, to ensure an improved look, will facilitate the sale of the coin on the numismatist market.

A distinctive form for storing coins, collectors are provided with such a possible option at their discretion and capabilities.

Try to shield coins from environmental influences. Changes in room temperature or contact with human hands.

Many were and are fond of this lesson in collecting rare coins. A collector's expression was quoted a long time ago: "first you feed the collection, then this collection feeds you."

Many connoisseurs - collectors of valuable coins strive for this statement.

We will acquaint you with safe methods of cleaning coins from an archaeological metal restorer with many years of experience in the Hermitage. An article about these methods of cleaning was posted in the book "The past of our homeland in the monuments of numismatics." The author of the useful material is OV Vasilyeva, an employee of the Hermitage. Let's move on to the most useful excerpts from the text.

Cleaning coins- one of the most important types of restoration, it is important for their study, dating, identification and storage.

Ancient coins made of silver and copper alloys found in hoards or in other archaeological excavations most often arrive at the restoration workshop heavily corroded, sometimes completely mineralized. Under the influence of water and salts, copper is destroyed in the soil with the formation of green carbonates and chlorides, red copper oxide and black oxide. Tin and lead compounds are found in the corrosive layers of bronze coins. Silver-copper coins are often coated with copper corrosion products. Sometimes silver under the influence of chloride salts turns into gray-violet chloride, horny silver. In air, copper alloys darken from oxidation, and silver as a result of sulfide formation.

Restorers are always very careful about the restoration of numismatic monuments. In particular, they make the right choice of the reagent necessary for cleaning them from corrosion, since a reagent successfully used for some coins may be unsuitable for others and will lead to their destruction or distortion of their appearance. It is desirable to achieve and preserve the noble patina, a kind of certificate of antiquity of objects.

So, starting to clean the coins, you should first of all find out what metal they are made of, whether they have a metal core, to what extent it has survived, what salts the coins are covered with.

Cuprous chloride

It is important, for example, in corrosion crusts on copper coins to determine the presence of copper chloride, which in humid atmospheric conditions causes an active corrosive process - "bronze disease". To detect copper chloride, a humidifying chamber is used: a glass vessel is filled with water to about 1/7 of its volume; a perforated plate made of plastic, plexiglass or porcelain is placed above the water, on which coins with a corrosion layer are placed. The vessel is tightly closed with a lid. In this state, it is left for 1-3 days.

The action of the humidification chamber is reduced to the acceleration of processes occurring under the influence of air humidity, which helps to identify foci of active corrosion and makes it possible to choose more successful cleaning methods. Also, the presence of coins in the chamber helps to loosen the surface layer of oxides, facilitating further cleaning operations. If there is copper chloride in the corrosive layer, droplets of liquid, colorless or slightly greenish, appear on the surface of the coins. Otherwise, the droplets do not protrude: copper carbonate, nitrous oxide and copper oxide are stable in humid conditions (horny silver on silver coins is also stable). And when copper chloride is found, it must be removed from the deepest pores and very thoroughly.

Sticky

Often during excavations, coins are found boiling, forming a shapeless mass. We do not recommend separating such coins by incandescence and immersion in cold water. To avoid losses, such a lump should be placed in a 5-10% sodium hydroxide solution and heated to 30-50 ° C. After that, the coins can be separated from each other, determine the condition of each of them and start cleaning.

Cleaning methods

The main methods of cleaning coins are mechanical, chemical and electrochemical. During restoration, a combination of the mechanical method with others is practiced.

Mechanical treatment consists in removing surface deposits: earth, sand and individual bumps of corrosion. It is produced with a variety of brushes, scalpels and dental burs of various sizes. But with rough use, they can easily cause scratches that distort the inscription, images, etc.

Copper coins

The chemical method, in combination with the mechanical method, cleanses coins covered with a thick layer of corrosion products, but retaining the metal base, as well as coins made of gold and silver.

To remove the cherry-red bloom of copper oxide from copper coins, the coins should be immersed in a 5-15% ammonia solution, but so that they are completely immersed in the solution, because in contact with air, the effect of ammonia on the metal will be destructive.

If copper coins are covered with salts consisting of copper carbonate (dark green), these layers should be removed with a 5-10% citric acid solution. It slowly dissolves copper salts and oxides and does not dissolve metallic copper.

There are also copper coins covered with a yellowish-pale coating of lead carbonate. This suggests that there is a lot of lead in the alloy of the coins themselves, or they lay in the ground with lead objects. To remove such plaque, a 10% solution of acetic acid should be used, which easily dissolves lead carbonate.

The restorer often has to deal with coins that are completely mineralized, which cannot always be preserved. The success of the treatment depends to a large extent on which compounds have replaced the metal as a result of complex mineralization processes. Surface deposits must be carefully removed first. If in this way it is possible to reveal this or that ornament, inscription, etc., then this should be limited. If mechanical processing has not opened the coin, a 5% solution of caustic soda or ammonium carbonate is used.

Attention! Since the degree of preservation of coins is different, it is difficult to give recommendations regarding their residence time in one or another reagent. Therefore, periodically removing the coins from the solution, the softened layers should be gradually removed mechanically, thereby accelerating the cleaning process.

Silver coins

Cleaning of silver coins is carried out mainly by chemical methods. Such cleaning is reduced to the removal of oxides and salts of other metals from the surface, mainly copper compounds. Copper connections on silver coins are recognized by their green color. To remove them, put a coin in a glass vessel or in a porcelain cup and pour 5% sulfuric acid solution. To speed up the process, you can clean with a heated solution, from time to time taking out the coin, rinsing with water (preferably running), then brushing off the mechanically softened salts with brushes. You can also use a 5-10% formic acid solution, preferably heated to 50-70 ° - the hotter the solution, the stronger its effect.

Formations of violet-gray horny silver are exceptionally soft. Such coins often lack a metal core, and during cleaning, the possibility of their complete loss is not excluded. But if the crust of horny silver is not too thick, the coin can be immersed in a 5-10% ammonia solution. In these solutions, horny silver is softened and then carefully removed mechanically.

The brass brush is a restorer's tool.

The method of electrochemical reduction can be applied to coins that have retained a metal core, but have very dense, hard, thick oxides, as well as to fragile coins. This method does not require special equipment. For electrochemical processes, zinc and aluminum are usually used. Practice has shown that for cleaning coins it is best to use plates made of sheet zinc or aluminum, with holes punched into them (like a grater). Formic acid of 5-10% concentration is taken as an electrolyte. A zinc or aluminum plate is placed on the bottom of the glass vessel. Several coins are laid out on the grated surface of the plate, which are covered with the grated surface of another similar plate. After that, the vessel is filled with the prepared solution so that the coins with the plates are completely hidden.

Processing in this way should be carried out especially carefully and carefully, with frequent monitoring of the process. Mechanically removing the reduced and softened corrosion products, the coin is examined with a magnifying glass to determine the degree of its cleaning.

Note that gold and new coins that have not been in the ground, but only have been in circulation for a long time, are cleaned quickly and easily. It is necessary to remove fatty substances from them with acetone, gasoline or alcohol and lower them in a 5-10% solution of citric or formic acid.

After cleaning

After cleaning the coins in one way or another, they should be thoroughly washed (boiled out) in several changes of boiling distilled water until the water is neutral according to the universal indicator. Following the washing, the coins are dried in acetone, then in alcohol for 30-60 minutes. For this purpose, you can also use a thermostat (special drying cabinet), keeping coins in it for no more than two hours at a temperature of no higher than 100 ° C.

If copper coins have an unpleasant sheen after cleaning, a light to dark brown patina can be artificially created. To do this, you need to take 50 g of copper sulfate and 5 g of potassium permanganate for one liter of distilled water. In the prepared solution, heated to 70-80 °, lower coins and keep until the desired shade is obtained.

After drying, the coins must be preserved with a protective coating - paraffin or synthetic resins. For this, 5% solutions of polybutyl methacrylate in acetone, toluene or xylene and polyvinyl butyral in alcohol or a mixture of alcohol and benzene (1: 1) can be recommended.

After conservation, it is necessary to store coins and medals not in piles, but in separate cells of albums or in trays with compartments.

Additional information on metal restoration can be found in the books by M. V. Farmakovsky "Conservation and restoration of museum collections" and H. D. Plenderlis "Conservation of antiquities and works of art".

Well, about more modern methods of cleaning coins using effective means, read on "MDRegion" and look at our channel on YouTube.