Cleaning silver coins by electrolysis. Cleaning a coin by electrolysis

I would like to immediately warn you about precautions when using this cleaning method.
Among coin collectors, electrolysis cleaning is the most popular method of cleaning coins. At the same time, it is used to clean other metal objects that require this procedure. In principle, the method is quite simple and not dangerous, but there are certain precautions that must be observed when using it.

Thus, assembly and use of a device for electrolysis cleaning of coins should only be done in a well-ventilated and lit area using chemical and electrical protective equipment, such as rubber gloves and goggles. Even if, it would seem, the risk of getting an electric shock is very small and you have used all protective measures, you must always be careful and collected when working with electricity and chemicals.

Electrolysis- the fastest way to clean coins. If cleaning with olive oil will take you several months to clean your coins, then using electrolysis you will do it in a few minutes. However, keep in mind that this is a fairly serious procedure and when you go through it, the risk of causing damage to your coin or even destroying it increases dramatically.

It will be like gambling, since the outcome of the process can sometimes be difficult to predict and the coin that showed great promise may not live up to it. Since electrolysis destroys the patina that covers the coin, everything will depend solely on the safety of the core of the coin. It happens that a coin consists entirely of patina. In this case, unfortunately, it will collapse.

Manufacturing of an electrolysis device

First you will need to find a suitable power supply. Any used unit designed for a voltage from 6 to 12 volts will be quite suitable for you. If there is such an opportunity, and you are going to frequently clean coins, then it would be best for you to buy a universal power supply on the market with four plugs, which is used to power tape recorders and receivers. Be careful when selecting a unit, since if you choose a device with high voltage, you will increase the likelihood of electric shock, while the efficiency of the cleaning process will increase slightly.

If you were unable to find a suitable power supply, take a car battery and repeat the entire process on it.

The next operation will be preparing the solution. To do this, select a not very deep plastic tray or container, pour water into it so that it completely covers the coin, and dissolve baking soda or table salt in it at the rate of one tablespoon per half liter of water. It is better to take soda rather than salt.

Dip two clamps into the solution and plug in the power supply. Notice from which contact gas will come out and a hissing sound will be heard. This will be a positive contact, the other will be, accordingly, a negative one.

The clip with the plus sign will need to be connected to the coin, which guarantees quick, “breakdown” cleaning. The other clip will need to be connected to a small metal object, such as a spoon or key. There is no need to use copper or brass objects for this; take iron or steel.

The so-called “stall” electrolysis occurs when the plus of the contact is connected to the coin. In this case, the speed of cleaning the find increases significantly, while the efficiency of the process is also very high. However, in this case, a certain side effect occurs in which the so-called “knocking out” of the metal molecules of the same coin from its surface occurs. Therefore, if your find is of particular value, it is better not to use this method, otherwise later its entire surface will “ripple”, and the remains of the relief located on it will be destroyed. In some cases, it is even possible that cavities may form on the metal surface.

In such cases, it is better to use the so-called “reduction type” of electrolysis, in which a negative contact is connected to the object being cleaned. When working in this way, cleaning occurs much slower, but the structure of the metal is somewhat restored from the oxides that affected them. However, the layer “restored” in this way has a very porous structure and can be easily washed off with the dirt on the object being cleaned.
So, using electrolysis, it will not be possible to restore at least partially the relief on the coin, but with “soft” cleaning the metal core will not be damaged and, accordingly, the coin will not be lost, and dirt, oxides and patina will be well softened, which will greatly facilitate them later cleaning from its surface. The resulting black layer is easily washed off with hot soapy water and cleaned with a trimmed toothbrush.

Cleaning coins

The actual process of cleaning coins using electrolysis consists of immersing the coin connected to the contacts of the power supply in an electrolytic solution. At the same time, it is better to take table salt for its preparation in the amount of two teaspoons, no more. If necessary, you can use baking soda, but the effect will be much less.

Depending on the size of the dirt layer, the cleaning process will take from half a minute to several minutes for “breakdown” cleaning, and from 40 minutes to a day for “restorative” cleaning.

During the process, gas bubbles should be vigorously released from the coin, and it should make a sound similar to hissing.

After the cleaning time is over, remove your find from the solution, remembering to first turn off the electrolysis device from the network. Next, you will need to continue cleaning the item with liquid soap and a toothbrush.

If necessary, the electrolysis cleaning procedure can be repeated, but you should not get too carried away with this, since each time the coin is subjected to destructive effects.
Moreover, if the contaminants are long-term and they have created a strong structure, it is quite possible that they cannot be removed using electrolysis, and mechanical cleaning will have to be used for this using special tools.
The solution remaining after cleaning can be used several times, but it will need to be changed periodically. The positive contact (anode), which is subject to wear during the electrolysis cleaning process, is also subject to periodic replacement.

Cleaning coins video

To clean coins using this method we need: power supply
12 volt (suitable from radio charger
phone or mobile) 2 crocodiles (can be used instead of crocodiles
secure with the wire of the charger itself) plastic or glass
reservoir (bath in which electrolysis will occur, you can
use a regular glass), salt or soda.

First, let's take the power supply. Cut the plug at the end
devices, separate the 2 wires and strip the ends
wires from insulation. Next we take our container (the container is not
should be metal) fill it with water. Water
there should be so much that it could cover our coin
and cleaned power supply wires. Add to water
salt or soda. (Below will be an experiment with the addition of
water instead of salt water.) In order to find out
which end of the wire to attach a coin to - lower it, free from
wire insulation, in water and observed from
which of them will cause bubbles to appear. TO
to the end from which the bubbles will come, we and
We attach our coin to another - a metal object.
As an iron object at the end of the wire you can
use an unnecessary spoon, key, blade. Attention after the process
electrolysis objects (iron) attached to the end of the wire
will fall into complete disrepair. Don't use those
items that you may need in the future!

This cleaning method is considered aggressive. So to begin with
practice on objects that don't represent
numismatic or archaeological value. In the future, you
You will understand whether this method suits you or not.

Below is this method of cleaning Garry coins by a forum member
violity using soda instead of salt
detailed description.

I would like to add a couple of useful tips to this topic.
There is one thing!-- Why use saline solution? At first I
and I tried to experiment with this myself
solution. I measured time and currents, while controlling coins every
10–15 seconds. Standing in the bathtub over this miracle of modern
progress (oxidizes over centuries, is removed in minutes, and then
seconds) from a young thinker, slowly turned into
a cackling old man. And the whole point is in the selection (albeit
not significant) chlorine. Symptoms disappear quickly after
an hour or two, or even earlier (someone
can say, like chlorine in small concentrations is even useful). But
I didn’t poison myself anymore. One search colleague - (for
thank him so much) he advised me to use baking soda. And oh
a miracle - this is truly the right electrolyte. There is zero odor, the gas is harmless
(carbon dioxide), the solution is a pleasant blackish-brown color, and not
poisonous green and when you pour it into
the sink is much easier to wash the container. Coins after saline solution
after a while they often become covered with a purple-brown coating or brilliant green appears
(by the way, electrolysis is probably one of the effective ways to kill this
greens -IMHO), this doesn’t happen after soda. Yes
soda is much more neutral for fingers. It was
once.

Two - something to attach as an electrode (a piece
iron, spoon, Ptr-ovskaya sleeve, gold ring) All metals have
disadvantage, it oxidizes, while dissolving in
solution. In particular, the cartridge vitriol and the reaction
becomes slow until it stops altogether.
file or sandpaper and again all in a circle. If you clean one
coin, there is no particular discomfort from the sleeve
it will - it won’t have time to oxidize, but if you need to clean the Augean
stables, then the best option is GRAPHITE! For experiment, you can disassemble
Chinese battery (not alkaline) and up to
she will live on ten coins. But then her hands... You can take a trolleybus
a brush (which is located near the TTU or just along the road) and
saw off a piece from it. Still, the best option is a brush
from electric motors. Durable, different sizes with
convenient wire for connection and in addition
long-lasting.

Yes
and crocodile clips, ala de China for 50 kopecks, this
nonsense. Look at radio markets, flea markets or from a TV specialist
Uncle Fedot's Soviets, from the so-called switch tseshki.
photo below: lower nibbler, worked out for about 30–40 coins
just wiped with a cloth, without using fur. funds. Compare it
with the new one and those you have lying around
Houses.

It is advisable to have an adjustable power supply, I
I use a homemade product from 1.2 to 27 Vs with current up to
3 A. Holding the object with a crocodile, I give the maximum for a short time and
after 5–10 seconds, when gas begins to evolve from
the entire area of the product (and not just the clamp)
I reduce it to 6–9 V. And it’s not at all necessary to “boil”
coin constantly - just alternate the method [layer blasting-cleaning]
several times in a couple of minutes to achieve the desired
result.

The use of various cleaning brushes is also
necessary in our business. Previously, in addition to dental I others
I didn’t know, but now I have 5–7 different forms of them and
appointments. Separately, I would like to highlight the cleaning brush
suede shoes like “TWIST” or other jewelry
the same type costs 5-15 times more expensive. It is advisable not to take
completely metallized, and the one in which there are
and nylon hairs. Although for superficial cleaning of all kinds of pieces of iron
the first one rules more. Try using it in a cleaning complex
objects and you will like the result. Does not remove patina
-unless, of course, you try to make fire out of a coin.

Silver is gradually becoming the most popular precious metal. Some sources already say with confidence that gold is receding into the background, giving way to gold. Of course, the issue of carrying out refining procedures in relation to silver is becoming more and more urgent. It is the details of this procedure at home that will be discussed in this article.

What is the refining procedure?

Extracting pure silver from various alloys that make up many contacts, transistors and relays is a long-established practice.

To obtain pure precious metal, it is necessary to use special technologies to purify it from impurities, which are collectively called refining. The essence of this procedure lies in its stages, through which it is possible to obtain pure silver, gold or platinum.

In general, this procedure is a purely industrial process, but nowadays silver refining can be carried out at home.

The following objects are suitable for cleaning:

scrap silver jewelry;
sludge from electrical cleaning of silver;
technological scrap containing silver;
the so-called “silver foam” is waste from the lead industry.

Methods

Alternative methods for refining silver include:

cupellation;
electrolytic method;
chemical methods.

The choice of refining method depends on the following factors:

amount of refined precious metal;
continuity of production;
the state of the metal that can be processed.

Did you know that the electrolytic method of refining silver is used when the starting material is high-grade silver.

In the event that silver is dissolved in the state of sulfate or chloride, it is most rational to use chemical or electrochemical treatment of the precious metal.

Cupellation

Refining of low-grade alloys is carried out by the cupellation method, which is based on the unique property of lead, molten with silver, to oxidize in air and separate from the metal along with other impurities.

It is important! The cupellation process does not separate the only gold, platinum and platinum group metals.

For cupellation, a special furnace with a cup-shaped crucible, which is covered with marl, is used.

Reference! Marl is a special porous limestone clay endowed with a feature that promotes the absorption of lead oxide.

The step-by-step process of silver cupellation can be represented as follows:

The oven is preheated.
An assay crucible with technical silver and lead is placed in the furnace.
The crucible must be heated until completely melted.
Atmospheric air is passed into the oven.
After the thermal reaction, the crucible is removed from the furnace and poured into molds.

After the alloy cools, it will take on a rainbow color. This means that it contains both silver and other precious metals.

Thus, by cupellation it is possible to obtain exclusively an alloy of silver with other precious metals.

Electrolytic method

Electrolytic refining of silver must be carried out in special cells made of plastic or sandstone that contain a solution of silver nitrate. The coefficient of pure precious metal in such a solution must be at least 50 grams per liter.

In this process, the anode will be contaminated silver, and the cathode will be thin strips of stainless steel.

The anodes should be placed in fabric bags, in which undissolved contaminants in the form of silver particles that have escaped electrochemical dissolution will subsequently be collected. Silver will be deposited on the cathodes in the form of macrocrystals. Such crystals grow towards the opposite pole until a short circuit occurs, to avoid which the branches of the crystals break when the solution is stirred in a direction parallel to the electrodes, at a short distance from the cathode.

Such crystals spontaneously fall into a basket at the bottom, from where they must be periodically removed. It is from these crystals that the ingots are subsequently cast.

Chemical method

To extract silver from salt or solutions, it is necessary to use a chemical method, as a result of which the precious metal is released in the form of black silver sulfate. To use this method, it is necessary to add sodium sulfate. The operation must be continued until the release of silver sulfate completely stops.

In general, in this procedure, the precious metal is recovered as chloride only after the addition of one of the alternative substances: either ammonium chloride or table salt. The resulting liquid must be settled until it is completely separated into two fractions: transparent and cloudy.

It is important! If the subsequent addition of salt does not cause the solution to become cloudy, then all the silver is in the precipitate.

Silver can be extracted from silver chloride in two ways:

dry, namely casting in the presence of alkali metal carbonates;
from the solution, bringing the sample to the maximum value.

Required materials and tools

In accordance with the descriptions of each of the individual methods of refining silver at home, we provide lists of materials and tools necessary for their implementation.

Cupellation:

Bake.
The crucible is in the shape of a cup covered with marl.
Lead.

Electrolysis:

Special cells made of sandstone or plastic.
Nitric acid.
Fabric bags.

Chemical methods:

Sodium sulfite.
Ammonium chloride.
Salt.
Nitric acid.
Sulfuric acid.
Special utensils, the material for which is selected depending on the components of the procedure.

Step-by-step electrolysis of silver at home

It is important! All the methods described above are applicable at home. However, if you do not have “refining experience,” then it is best to use the electrolytic method of refining silver.

Conventionally, this process can be divided into three parts:

Dissolution of precious metal in nitric acid.
Cementation of silver and its fusion.
Direct refining.

At the first stage you will need:

nitric acid solution 68.8%;
glass container;
quartz stick.

Nitric acid 68.8%, deionized water, scales, glass container and quartz rod

It is important! When working with acids, do not forget that you need good ventilation (it is best to work in fresh air), protect the skin of your hands with gloves, your eyes with safety glasses, and pour the acid into water, and not vice versa.

The process of selecting proportions

To obtain dilute nitric acid, you need to mix deionized water with pure acid in a 1:1 ratio.
Mix the resulting liquid with a quartz stick.
We pour the acid into special containers for chemical reagents.
We prepare silver nitrate based on the entire process. We need a concentration of approximately 50 grams of silver per liter of liquid.
Dissolve silver in liquid. This process is usually accompanied by the release of NO2 gas and the solution turning blue.
The dissolution process is long. Silver will completely dissolve no earlier than after 8–10 hours.
The resulting solution should be sealed in a chemical jar.
Next we get “silver cement”. To do this, it is necessary to displace metallic silver from silver nitrate with copper.
Take a solution of silver nitrate, add copper.

It is important! Old water pipes that need to be cleaned to a shine can be used as a source of copper.

This is what copper tubes look like in solution

The addition of copper provokes an acceleration of the reaction. The resulting silver cement on the tubes is silver in powder form. To ensure that the speed of the process does not decrease, it is necessary to periodically shake off the cement from the tubes into the solution.

Silver on copper tubes

The reaction occurs due to the fact that the tubes “give up” copper to silver nitrate, so they can gradually dissolve completely. If this happens, add new straws.

As the silver is displaced, the reaction becomes slower, so you can safely leave it unattended for several days. You only need to monitor the presence of copper in the solution and the absence of foreign objects in it.

It is important! The completion of the reaction will be indicated by a cooled solution without signs of reaction, the presence of a clear blue liquid on top and a layer of cement at the bottom.

Now let's start filtering the cement. At this stage you will need:

funnel;
coffee filters;
capacity.

Items required for filtering

It is important! The filtration procedure must be repeated at least five times. This will remove any remaining copper nitrate from the silver cement.

After the filtration procedure is completed, it is necessary to collect the remaining cement, evaporate excess moisture or wait until it evaporates naturally.

It is important! The solution after filtration may contain silver. Therefore, we advise you to add table salt to the remaining solution and leave this liquid to wait for a precipitate in the form of silver chloride.

The resulting dry cement must be melted in a crucible. We heat the cement evenly and consistently.
We perform casting in water, which will allow us to obtain grains for further work with metal.
The silver obtained at this stage is a precious metal of approximately 980 fineness, that is, the alloy still contains foreign impurities. To extract them, move on to the next step.
Before this, the resulting alloy is melted into a bar (small ingot).

For the third stage (direct refining) we will need:

power unit;
the lower part of a plastic container with a volume of two liters;
tea or coffee filter;
stainless steel fork;
insulating tape;
brass stick;
heat shrink tube insulation.

Components required for the third stage

A strip of pure silver must be welded to a silver form (ingot, bar, etc.). Its edge should remain hanging.
Now let's create a cathode using a fork, insulating tape and pliers.
We pass the anode stick through the tea filter and place the objects (the lower part of the eggplant, the tea filter, the brass stick) as shown in the photo below.
The silver solution we prepared earlier is diluted with distilled water, bringing the total volume to two liters.
We immerse the cathode in the form of a fork into the electrolytic bath, fill it with electrolyte so that there is no contact with the junction of the tape and the silver bar.
Next, we connect the minus to the plug, and the plus to the brass stick, and apply current.

It is important! The voltage should fluctuate between 4-8 volts, and the current should not rise above five amperes.

The silver crystals will begin to grow, so it is important to ensure that they do not grow into the anode bag as this will cause a short circuit.

Once the reaction is complete, the silver bar will dissolve. The electrolyte needs to be poured into a jar (it can still be used). Silver crystals must be washed in clean water several times, filtered and dried.

This way we get 999 silver.

Video of obtaining pure silver from mirrors (in 2 parts)

Refining silver at home can be an interesting and exciting procedure for you, and its results can be long-awaited and exceed your expectations. Each method is unique. The effectiveness of the chosen refining option directly depends on the effort applied.

Cleaning coins with electrolysis is a risky method, especially for a beginner, so you should start with coins that are not particularly valuable. Even ordinary soda can ruin a coin, but electrolysis can cause serious harm to money - completely erase the patina or cause irreparable damage to the coin. It is impossible to get rid of such damage, which means that the value of the coin will decrease.

Cleaning a coin by electrolysis

What is needed for electrolysis?

Cleaning by electrolysis will require minor economic costs. The duration of the procedure is from 10 to 40 minutes, but sometimes cleaning can last for an hour. You should not leave money unattended, soak it in a solution or clean it by electrolysis throughout the day.

For the procedure you will need:

Two alligator clips or applicator clips, you can purchase them at a hardware store.
Deep dishes made of glass or plastic; if you don’t have one, a regular glass will do.
Adapter with power from 6 to 18 amperes.
Distilled or purified water from a bottle.
Baking soda or salt.
Concentrated lemon juice.
Stainless steel spoon.

Carrying out such a procedure requires the availability of protective equipment. You will need:

Latex gloves.
Safety glasses or mask.

The electrolysis process is usually accompanied by the release of gas, so the procedure should be carried out in a well-ventilated area.

If salt was added to the solution to clean money, then during electrolysis the salt ions break down into sodium and chlorine. Chlorine is released in the form of gas. Since contact with this substance is dangerous to human life and health, it is recommended to carry out the procedure with a mask or use soda instead of salt.

When cleaning banknotes, be careful; the adapter may become hot during the cleaning process. If it gets very hot, then you should not leave it without attention - there is a high risk of fire.

Particular attention should be paid to the solution. You need to add 2 tablespoons of soda or salt to the water. Cleaning coins by electrolysis can be done by adding lemon juice to the solution, 20–30 grams is enough. Lemon juice will increase the effectiveness of the procedure and help remove dirt from the metal surface.

How is the procedure done?

Step-by-step cleaning description:

first, disconnect the stamp from the adapter and expose the wires;
then install clamps to each wire;
prepare a solution for the procedure;
find out which terminal the negative charge goes to and which the positive charge goes to.

A wire with a positive charge should go to the spoon, and a wire with a negative charge should go to the coin. If you can’t figure out the wires yourself and you don’t have a tester at hand, you need to place a spoon and a coin in the water so that they don’t touch each other. If a wire carrying negative current is connected to a spoon, it will begin to bubble; if this wire is connected to a coin, it will begin to bubble.

Electrolysis cleaning steps

The minus is not capable of harming the metal of the coin, but it is still worth carefully monitoring its condition. Periodically remove the product from the solution and check the degree of cleaning.

Observing the process, you can see how dirt peels off the surface of the metal and moves away. Cleaning coins involves changing the color of the solution. During the procedure, it is able to change color, darken and turn black. This happens not only because the dirt moves away from the metal, but also because the clamps in the solution oxidize.

After the procedure, it would be useful to polish the money - they must be rinsed under a stream of water, and the surface cleaned with a toothbrush. The surface of the metal is then polished using a piece of suede. If there is no suede, then wool without lint and pellets will do.

During the cleaning process, you may notice how the surface of the coin becomes covered with black flakes. You can easily get rid of them by brushing: for this you need to periodically check the degree of contamination of the product, removing it from the solution every 15 minutes.

Don't go overboard as cleaning with electrolysis can cost you money. Minor damage may form on the metal surface and the patina will disappear.

If the dirt stuck to the coin cannot be cleaned, then you should not experiment and repeat the procedure using electrolysis; it is better to give the coin to a restorer for cleaning.

Peculiarities

Cleaning copper coins by electrolysis has a number of nuances that you should know about before starting the procedure:

lemon juice will enhance the effectiveness of the procedure, but the acid can harm the metal;
adding soda to water will also make cleaning more productive, but salt is more effective;
the release of gas and the appearance of bubbles indicates that the cleaning process has begun;
If the water does not bubble too actively, then the reason lies in the power of the adapter.

The work of a restorer is difficult to compare with cleaning by electrolysis, but if there are no other options, then you can use a similar procedure.

Coins that are valuable should not be cleaned this way. Before carrying out the procedure, you still need to practice on cheaper coins.

In general, the method is not bad and quite effective, but it is not recommended to risk a valuable piece of the collection. You can try cleaning the metal with a brush or simply washing the coin in warm water with soap.

Metals oxidize for several reasons, and sometimes you should leave a coin in its current state if there is a risk that cleaning will do more harm than good to the item. The collector is able to clean the coin himself after purchasing it.

Many collections contain good coins (without mechanical damage), but with dirt or dark spots. The problem can be solved in various ways to eliminate external defects. We'll talk about them in this article.

Types of coin cleaning

Depending on the degree of contamination, characteristics of the material and other factors, it is necessary to decide on the appropriate method. Among the main types of coin cleaning are the following:

chemical,
mechanical,

cooking,
electrolysis.

The chemical type of cleaning involves the use of ammonia, acids, soda, soap, detergents and washing powder. If you have concentrated hydrochloric acid, you can make a special bath with a solution and immerse coins in it. After the procedure, it is better to rinse the coins with alkali to stop the reaction.

Cleaning warm soapy water Suitable for most metals. You can consolidate and enhance the effect obtained with any dishwashing detergent; ordinary laundry soap will also give a good result. Coins with minor stains should be soaked in the resulting solution for 2-3 hours. Coins with heavy deposits can be kept in the prepared liquid for about a day.

How to clean a coin with soda

Cleaning with soda is an alkaline method of removing dirt and is suitable for items made of low-grade copper and silver. The process is carried out easily, without creating special conditions. First, a paste is formed from a spoon of soda and a small amount of water, then the mixture is applied to the coin. Dirt is removed with a regular soft brush. Baking soda can also be used after acid cleaning to extinguish the reaction.

How to clean a coin with vinegar

Cleaning using vinegar or citric acid Suitable for hard metals. A teaspoon of soda is added to the vinegar solution and the liquids are mixed. Coins are immersed in the resulting bath and left there until the stains disappear, and then treated with soap, warm water and a soft brush. If the dirt is not washed away, the procedure is repeated.

It is not advisable to use this method for coins made of gold, silver or copper.

Cleaning coins by electrolysis

Electrolysis– the most dangerous, but also the fastest method of eliminating defects. Cleaning is done by applying current to a lightly salted solution of water with a coin placed there. We will talk about this method in more detail at the end of the article.

Ammonia as a coin cleaner

Cleaning with ammonia is suitable for items made of silver, pure copper or alloys containing copper. The coin is dipped in ammonia for the time required to achieve the effect, then removed and washed. The room in which such cleaning is carried out must be well ventilated.

Mechanical cleaning

For mechanical cleaning, various objects and tools are used (drills, brushes, needles, scalpels, pieces of fabric, etc.). This method is quite effective and removes any contaminants, but there is a risk of damaging the surface of the products.

Boiling down coins

When cooking, the coin is processed in a boiling liquid; you can additionally use oil (vaseline or olive).

Several coins are placed in a pan with hot oil for 10 minutes(it is more convenient to clean in a special lattice box on a chain). After cooking, you need to wash the products with a brush and soap and remove any remaining oil by thoroughly boiling the coins in distilled water.

After cooking, the specimens acquire radiance and shine, but a noble patina disappears from them, giving the products additional value. It is better not to expose rare coins to such influence.

Rules for cleaning gold, silver and copper coins

The choice of the optimal method is made taking into account the specific properties of the metal. Cleaning carried out in the absence of the necessary knowledge and experience will not give the coin its original appearance, but will significantly damage it. For example, mechanical impact using acidol or jewelry paste leaves scratches and helps erase small details of drawings.

Cleaning gold coins

Gold coins do not require aggressive cleaning. If dirt appears on the products, it will be enough to wash them with warm soapy water, rinse with water and dry. You should not rub gold coins vigorously because even ordinary fabric leaves on noble metal small scratches.

Cleaning silver coins

Choosing the appropriate cleaning method for your silverware depends on on the sample and degree of oxidation of the metal. High-grade silver coins can be cleaned by placing them in a solution of ammonia (10% ammonia and 90% water) for an hour or in a soda solution (30 g of soda per 100 ml of water) for several hours. The process will speed up if the liquid is brought to a boil several times and the oxidized areas are treated with a soft brush.

High-grade coins with minor traces of oxidation are best cleaned with a mixture of toothpaste, ammonia and baking soda. The resulting mass should not contain abrasive particles. The coin should be covered with the mixture and rubbed with your fingers or a brush.

Suitable for cleaning low-grade silver coins Trilon B solution. When the green layer disappears from the surface of the coin, you can continue the process using a special mixture for silver of a certain standard.

Cleaning Copper Coins

Copper products are susceptible to the formation of a patina layer on the surface. If there are no signs of corrosion on the coin, and the film is uniform, then it is better not to risk it and not to clean the coin. Patina protects metal from corrosion and gives the coin a noble appearance. To remove traces of touch and grease, the product can be washed in warm water.

It is better to clean coins that have been corroded using aggressive reagents (acetic and citric acids, Trilon B). They will gradually separate the damaged layer of metal without affecting the solid base. To process weakly oxidized coins, soaking them in the solution for several hours will be sufficient, while highly oxidized coins can be left for a day or more.

Cleaning bronze coins

Bronze products are cleaned according to the same principle as copper ones. But you need to keep in mind that ammonia changes bronze color. The metal may turn brown or even black. The shine of a bronze coin can be easily restored by applying toothpaste to its surface and washing it in warm water. After cleaning, you need to dry the items by wrapping them in two layers of soft cloth and paper napkin.

Sulfuric and nitric acids should not be used to clean copper or silver coins as they destroy fine details of the design.

Coin Cleaning Tools and Supplies

In addition to the above methods, there are others. Tools that are suitable for cleaning:

toothbrushes of varying degrees of softness;
wooden toothpicks;
brush with natural bristles;
plastic dishes, tweezers;
reagents (soap, distilled water, soda, linseed oil and vaseline oil).

It is not recommended to clean rare and valuable coins yourself - professionals will do a better job. The following cleaning methods are suitable for dug metal. The main goal is to preserve the patina when cleaning, removing all unnecessary oxides. Before processing, coins are washed with soap.

The Best Safe Way to Clean Coins

The simplest and safest method is using laundry soap. Boiling water is poured into a hermetically sealed plastic container and grated 72% laundry soap is poured.

When the solution thickens, coins are placed in it. After a day or two, the coins are removed and wiped with a toothbrush with trimmed bristles. The procedure is repeated until the desired result is achieved. Some oxides can be carefully removed with a wooden toothpick.

The disadvantage of this method is that it takes a lot of time, but its undoubted advantage is that the excess layers are removed carefully and gently.

Exposure using caustic soda is a very quick method, but suitable not for all coins. Both products with a relatively flat field and those with an uneven thin film can be cleaned well.

When preparing caustic soda solution, safety precautions must be observed. Dissolve the granules (1 sachet per 500 ml) only in distilled cold water, take the coin with tweezers and be sure to work with gloves.

The product is immersed in the solution for 10 minutes. Then washed with water. After this, the softened oxides can be easily removed with a brush.

If during the cleaning process the oxide on the product turns blue or green, the process must be interrupted immediately.

Cleaning Copper Coins

Careless cleaning of a copper coin can cause chips and pits to appear on its surface. Depending on the type of corrosion, the appropriate method of exposure is selected. The reddish coating can be removed with a five percent ammonia solution or ammonium carbonate. You need to hold the coin in ammonia solution no more than 1-2 minutes. Green plaque can be removed with a solution of citric or acetic acid. The yellowish coating is dissolved with a 10% acetic acid solution.

After cleaning the coin using any of the above methods, it must be boil in distilled water. After several boils, you can check whether the coin is completely clean by dropping a 1.7% solution of silver azone into the water. If after this the water remains clear, then the cleaning process must be completed.

After cleaning, the product must be thoroughly dried. You can place the specimen in a special drying cabinet for two hours or dry it in acetone and then in alcohol (no more than an hour).

If the natural patina on the coin could not be preserved, you can apply artificial to give the product an attractive appearance. Per liter of distilled water, add 50 g of copper sulfate and 5 g of potassium permanganate. The resulting solution is heated to 80-90 degrees. Coins are placed in the heated liquid. Next, you should turn the coins over from time to time and wait for the desired color to appear. After the procedure, the coins need to be dried and coated with a 1:1 mixture of alcohol and benzene to protect them from corrosion. You can also read about artificial patina in the article “”

Electrochemical cleaning

Electrolysis- a quick and effective way to remove dirt, but its use is associated with some dangers inherent in the operation of any electrical appliance. The device should be used in a well-ventilated and lit area. Before carrying out the process, you must wear protective gloves And glasses.

When using electrolysis, the risk of spoiling a coin increases significantly (compared to other methods - several times). Assembly requires a power supply with voltage 6-12 volts. The plugs are cut off and the wires are divided into two parts. The ends of the wire are cleared of insulation. The copper strands must be twisted, soldered, or attached to metal clamps. Next, take a shallow plastic container and fill it with saline or soda solution (1 tbsp per 0.5 l).

Turn on the power supply. The clamps are held at isolated places at a distance from each other (if they come into contact, a short circuit will damage the power supply). The clamps must be immersed in a container with a solution. On one of them there will be hissing and gas release - this is “+”.

It needs to be connected to a coin, and the second clamp (respectively “-”) is connected to a small metal object (for example, a spoon or a key).

The second option is a reverse connection. The positive terminal is connected to a metal object, and the negative terminal is connected to a coin. The reverse connection gently cleans the coin and does not harm its metal core.

Depending on the amount of plaque and the degree of contamination, the cleaning process takes from several minutes (if “+” is connected to the coin) and from 40 minutes to 4 hours(if “-” is connected).

Having finished cleaning, you should turn off the device from the network, remove the coin from the solution and clean it with a brush and a small amount of liquid soap. To remove special, complex contaminants, the procedure will have to be repeated. The solution will become dirty after some time and will need to be replaced to perform repeated electrolysis.

Summing up the topic of cleaning

A method of cleaning coins that would allow them to return exactly to their original appearance, does not exist, but with due diligence you can significantly improve the condition of the coins. The safest option is to use a soap solution.

More serious stains may require soaking coins in the solution for a long time. Sometimes you have to wait several weeks for results.

With prolonged soaking the solution needs to be changed to a new one, and periodically remove the coin itself and clean off the softened layers of dirt from it. This cleaning method is ideal for gold coins.

After the procedure, the product is dried and wrapped in a soft cloth. Mechanical cleaning is also considered a relatively safe method, but is absolutely not suitable for soft metals that are easily scratched.

the main task– do not completely spoil the coin and do not deprive it of its noble patina. Some specimens are better not to be cleaned at all, but simply washed. It is recommended to practice on the simplest coins before starting work. It is imperative to follow safety regulations (chemical cleaning methods can be hazardous to health).