Coin patination is fast and effective method give them an antique look. There are many ways to apply a dark coating, you need to choose them depending on the type of metal and the desired shade. Most often, copper surfaces are subjected to the procedure, but sometimes coins made of nickel, bronze and even silver are aged.
The word "patina" refers to the terms Italian. For the first time, they learned about it after a chemical experiment, the reaction of which was the transformation of the surface of the coin. On a silver or copper alloy, a dark coating looks beautiful, but on aluminum it is a cloudy film, which is why such specimens lose value.
An important condition for patina is the complete coverage of the metal, because. individual spots will not add to the charm of the coin. Therefore, the uneven coating is removed and applied artificially. But, if the oxide film has penetrated deep into the alloy, it is not recommended to touch it. After cleaning, such products will turn into thin plates with shapeless ruts instead of a pattern.
Patination of coins is carried out for several reasons:
- the copy was bought or found in poor condition, with traces of corrosion, in need of cleaning. The appearance of dug out money samples largely depends on the area in which it was found and the quality of the soil;
- cost increase. Ancient coins with a noble brown coating are much more valuable than specimens with green spots on the surface;
- ignorance of the true value of a coin with natural traces of oxidation and the desire to give it shine leads to the loss of the product of its significance. Most often, the patina is erased or the coin is thrown into acid, after which its color becomes yellow-orange.
Patination is carried out by a chemical reaction, during which a film or plaque is formed. Many years of practice has shown what methods of applying patina exist and how to perform the procedure at home. In the process, you need to observe the proportions of substances, otherwise you can lose a rare coin forever.
Rules and methods of patination
It's no secret that metals oxidize over time under the influence of air and water. But this happens in different alloys in different ways. If steel or iron is destroyed as a result of such exposure, then copper is covered with a dark protective film. It is this layer that gives a special chic to antiques, testifying to their authenticity.
Often, in the desire to remove dirt from a coin, it is subjected to mechanical processing, as a result of which the patina is also removed. It is quite possible to return the noble insignia after this. Often, artificial patination of copper coins is justified from an aesthetic point of view, as it helps to hide the results of their cleaning.
Required Tools
Depending on the chosen method of applying the patina, it is necessary to prepare tools and materials. The minimum set includes:
- glass or plastic container;
- selected chemical reagent;
- beaker;
- stirring sticks;
- synthetic brush;
- degreasing liquid;
- latex gloves;
- respirator;
- soap;
- sponge
- unnecessary clean rags;
- cotton pads.
When all this is collected, you can begin to conduct the experiment.
The patina process
Of course, the presence of a “native” layer of oxides is much more preferable, because it not only speaks about the value of the copy, but also reliably protects the coin from damage. If it is possible to preserve natural plaque, then it is better not to touch it. When artificial aging is indispensable, the patina is applied independently. Patination is usually carried out by one of the following methods:
- dip the coins in the prepared solution;
- place a monetary sample in a vapor-gas environment;
- apply the composition to the surface with a brush.
The quality of the final result directly depends on the method of obtaining the patina and how well the coin was prepared.
First of all, the coins are cleaned of fat and oxides. Do this with a cotton pad soaked in white spirit or gasoline. These liquids are good at removing greasy traces that interfere with the oxidation process and the reaction of the patinating solution with copper. It is also necessary to wear gloves, because. on the left fingerprints, the patina will lie unevenly.
Features and methods of patinating coins at home
Depending on the metal, there are a fairly large number of methods for applying patina to a coin. All of them are feasible and do not require the knowledge of ancient alchemists and special laboratory. Most types of patina are induced simple ways, but do not expect super-effect from it. Coin defects, such as holes, ruts, nicks, smudges, the resulting layer will not hide, but only change their color.
The better the patination is done, the more valuable the coin will become. Experienced collectors know that artificial plaque does not add financial value to items. But the patina, induced according to all the rules, is no different from the natural one. The coin acquires a noble rare appearance in the eyes of potential buyers. There is no universal method of oxidation, and the most suitable of all is selected only experimentally.
Patination of copper coins
Copper coins are patinated with sulfuric acid. The tool is applied to the metal, and literally within a few seconds it darkens. After the procedure, the product must be washed with soap so that oxidative processes do not continue. The patina obtained from sulfuric ointment has a fairly rich black color, but it is unstable. If you rub the surface with a cloth, the plaque will be erased, so this method should be used as a last resort.
Patination of copper coins ammonia carried out in a well-ventilated area, tk. vapors of the substance are quite caustic. The processed coin is oxidized in a closed jar or container. To do this, it is placed in a container with ammonia so that it comes into contact only with its fumes, and not with the liquid. The container is tightly closed and wait 15-30 seconds. If the coin is left for a long time, then it can be ruined. The patina will not become darker, and pockets of corrosion will appear on the product.
Coping with the task of processing a coin with ammonia is easier in words than in deeds. It is either suspended or placed on a cotton pad inside the jar. This will allow it to patina evenly on both sides. Alcohol is poured at the very end, after preparatory manipulations. Then tightly close the container with a lid.
Vapors of ammonia are able to cover the coin with an even layer of pleasant patina in a few minutes. Brown. Glitter is eliminated, and the product acquires a beautiful rare look.
Patination of coins with potassium permanganate and copper sulphate gives a quick result and a brown tinge. Dishes for work are taken unnecessary, because. after patination, it is unlikely to be washed off and will have to be thrown away. To prepare the solution, take 200 ml of distilled water and one gram of powders. Everything is thoroughly mixed, brought to a boil on the stove and a coin is lowered into the resulting composition for 1-2 minutes.
The longer the coin is in solution, the darker the patina will be. After 10 minutes, the product will become almost black. This must be taken into account when achieving the desired shade of the oxide film.
Patination of silver coins
It is quite easy to give silver coins a dark color. To do this, you need ammonia or ammonia. The product is placed in the freezer for 20-30 minutes. After that, they take it out, take it with tweezers by one edge and bring it to an open bottle of ammonia. She literally immediately begins to react to vapors of ammonia and becomes covered with a gray coating of patina. I stop the procedure when the silver acquires the desired shade.
There is another way to patinate silver coins - boiled eggs. They are boiled to a steep state, cut in half and placed in a container with a fairly narrow neck. The coin is also sent there. The egg begins to emit hydrogen sulfide, which is why the coin is covered with a gray film. This method is good in that it achieves the most uniform coverage.
The nuances of patinating coins in a natural way
It is possible to apply patina to a coin without using the materials described above. There is a way to patinate bronze naturally. For this, the products are taken out into the sun and left there for quite a long time. For 1-2 years, you need to ensure that the coin is exposed to sunlight all the time. Of course, such a process can hardly be called fast, but its plus is that copper will take on a natural aged look. The "solar" patina will be difficult to distinguish from the natural layer of oxides.
At home, you can try to bring a dark plaque with a tree. Some types of wood release tannins that contribute to the "cabinet" patina.
If there is no experience in patination of coins and even a clear idea of how this process takes place, it is better to abandon the idea or leave it to a specialist.
Often, after cleaning, the coin looks really bad, I would even say not really bad. This is mainly due to the fact that the so-called patina was destroyed and the coin remained in the negligee. Selling such a coin is very problematic. It is necessary to prepare it a little for sale (like a car), i.e. apply patina.
Patination of copper coins, in principle, is not very difficult. The main difficulty is that the acquired color resembles natural as much as possible. There are many ways to patinate copper coins, each has its pros and cons. I only use three methods. I'll tell you a little about them.
Patination of copper coins with manganese and copper sulfate. Many numismatists consider this method to be the most “ideal”, since the color of the coin can be made from red to dark brown, and this induced patina will be very similar to natural. Patination occurs as follows - in water heated to 90 degrees (0.5 liters), add 3-4 grams of manganese and about 10 grams of copper sulfate. Mix everything and place coins in this solution. Warm the solution slightly as it cools. Turn the coins every 5 minutes and check their color. Achieve the color to become bright brown. A big plus of this patination is that the color is beautiful and relatively resistant to washing off.
Patination of copper coins with sulfuric ointment. "Real" numismatists despise this method, which is quite simple. Take a coin and smear it lightly with your fingers with sulfuric ointment. All this should be done in barely warm water. Water is needed so that the staining process is slower. At the output, the color of the coin will be from dark brown to matte black. The advantage is that the most dead coin can be revived a little, and the disadvantage is that the color is unnatural and the patina is very easily washed off. In order to make the patina natural, after patination with sulfuric ointment, the coin must be rubbed with a soft cloth dipped in oil. Sometimes you can achieve a very good color.
I really like to patinate copper coins in a natural way, i.e. sun and air. He conducted such an experiment - he put the coins, cleaned to the very "nudity", on the roof of the house. I turned over the coins every two weeks. For four months the coins were burned by the sun and washed by the rain. The result was normal - the color from bright red to dull brown. If the coins had lain in the open air for at least 7-8 months, then they would have become ideal. I highly recommend this method for those who are not in a hurry. The result will be amazing.
It has long been known that metals oxidize over time when exposed to atmospheric oxygen. And if iron is destroyed as a result of this, then copper is covered with a patina - an oxide-carbonate film that slows down the oxidation process. It is the patina that gives a special charm to an old coin, indirectly testifying to its authenticity. Unfortunately, during the cleaning process, along with the dirt, the natural patina has to be removed. However, by patinating copper coins, you can restore them to the look of undisturbed antiquity. Often, artificial patination of coins is justified from an aesthetic point of view, as it helps to retouch the results of their cleaning.
There are many ways to patina copper coins. With any patination method, the same set of tools is basically used. It is enough to have on hand:
- a glass or plastic container for preparing solutions;
- bath for washing;
- spoon
- beaker;
- table scales;
- glass and wooden sticks;
- brush;
- degreaser;
- latex gloves;
- respirator;
- laundry soap;
- sponge
- rags;
- paper towels.
Before and after patina
The patina process
Undoubtedly, the presence of a "native" patina reliably protects the coin from damage. Ideally, it is better not to touch it at all. However, sometimes the removal of collection merits is a necessary measure for the following reasons:
- due to the onset of corrosion;
- great pollution;
- strong uneven patination layer.
In such cases, you have to resort to self-patination. In this regard, a reasonable question arises, how to apply an artificial patina to a copper coin? The essence of this process is the impact on copper of chemicals and compounds.
For patination, the following methods are usually used:
- coins are dipped in a patinating solution;
- apply the solution to the surface with a brush;
- place a banknote in a vapor-gas environment.
The quality of an artificial oxide-carbonate film depends on the method of its production and on how well the base is prepared for it.
Preparing a coin for putting on a patina consists in cleaning its surface from grease and oxides. It is easier to do this with a cotton pad dipped in white spirit or gasoline. These solvents will help clean it of greasy traces that make it difficult for the patination solution to react with copper. From this point on, it is imperative to wear gloves, because the patina does not lie evenly on the left fingerprints.
Ways to build a patina
IN aqueous solution copper sulfate and potassium permanganate. To restore a beautiful golden brown patina, it is enough to dilute two teaspoons of copper sulfate and 1/3 teaspoon of potassium permanganate, commonly referred to as potassium permanganate, in 200 g of water. Heat the solution in a water bath, but do not boil. Dip the coin briefly into the solution several times until the desired color is obtained. Upon completion of patination, the banknote should be thoroughly rinsed under the tap and dried. Matte can be easily removed with a woolen cloth.
With the help of ammonia. This method has two implementation options:
- Pour ammonia into a small container, for example, into a cork from plastic bottle, place it in a plastic container along with the coin that you want to age, then close it tightly and leave it for a while. The result becomes noticeable after 1-1.5 hours.
- Fix the coin on any thin wire or thread. Place it in a glass jar with a small amount of ammonia so that it hangs over the ammonia. Remove the end of the wire from the jar, closing it with a lid. The reaction will begin very quickly, and changes will occur literally before our eyes. With the help of ammonia vapor, the desired effect will be achieved much faster than in the first version, after 10-15 minutes.
By the way! You should not resort to heating ammonia vapors, otherwise the patination result will be spoiled by the resulting condensate.
Sulfur ointment. In fact, this drug is intended for the treatment of scabies, but it is often used to induce a patina. It is worth noting that in this respect it is very effective, since it contains a lot of sulfur. Contact of copper with sulfur leads to the formation of copper sulfide. This compound quickly turns black and firmly covers the entire surface of the banknote. Therefore, to obtain a light brown patina, you need to act a little differently.
It is better to apply quite a bit of ointment on the pads of washed fingers, rubbing it over the surface with a thin layer. After that, do not touch the coin with sulfur fingers. Next, you need to pour hot water into the bath and lower the coin pre-washed in citric acid into it. Then, with sulfuric fingers, take it under water and begin to rub the ointment into its surface, without lifting it into the air. When you get the desired color, wash the coin with a brush with "Fairy" without removing it from the water. As a rule, the effect obtained exceeds all expectations. Whereas the performance of such manipulations directly in the air leads to the formation of an unattractive black patina, which, moreover, begins to fall off very quickly.
in a solution of copper oxychloride. Pour hot water into a half-liter jar. Dilute in it two tbsp. spoons of copper oxychloride (HOM). This substance easy to find in fertilizer stores. The result is a saturated blue-green solution. 100 ml of ammonia should be added to it. From now on, it is better to work in a respirator so as not to smell the suffocating smell of ammonia.
A copper coin must be immersed in the prepared solution and left for 30 seconds. Then take it out and inspect. This manipulation must be repeated several times until the desired effect is obtained. Finally, the coin should be washed in soapy and clean water, dry and admire the beautiful brown-olive patina.
In general, if you forgot that this should not be done and washed away the natural patina, it will be quite possible to restore it.
If the composition of the alloy from which the coins are minted includes copper or any of its compounds, then sooner or later a film will appear on the surface of the metal - patina. She has the most different colors and shades, and its appearance is justified by the oxidation of copper. It is also called noble rust, and all because the coin in such a shell is not subject to corrosion, has an attractive appearance. The patina is valued by collectors as it gives the collection an elusive sense of antiquity.
If a coin needs to be cleaned, but as a result it will lose its patina, do not be upset. Artificial coins will come to the aid of numismatists patination which can be done even at home. Now there is no need to wait long months for the patina to appear naturally.
Patination of metal banknotes containing copper
Patination of copper-containing coins is possible in three ways.
- In the first option, 20 grams of copper sulfate and 5 grams of manganese are required. They are dissolved in a liter of water, and then heated to 90 degrees. It is required to carefully monitor the temperature, avoiding boiling, otherwise the result is not guaranteed. Prepared coins are lowered into the hot solution, turning them over from time to time so that the patina is layered evenly. It is impossible to say exactly how long it will take you to fully patinate, since there are many options for the desired color. Someone needs to get a dark brown coin, and someone needs a reddish tint.
- For the second option, you will have to look into the pharmacy to buy sulfuric ointment there. Lubricate the coin generously with this ointment and set aside for 3-5 minutes. Patina with this method is formed very quickly, almost instantly. To prevent the metal from turning black, it is better to carry out the procedure near a tap with water. As soon as you see the coin turning brown, rinse off the ointment thoroughly. Didn't make it on time? It's not worth getting upset. Take Vaseline or vegetable oil, moisten a soft cloth in it and polish the coin to the shade you need.
- The third option for patination is possible in the presence of sodium hyposulfite, which can be purchased under the guise of a fixative for developing photographs from film. Slightly warm the 10% solution and dip a clean and pre-degreased coin into it for 10-20 seconds. The resulting brown tint will not only please your eye of a professional numismatist, but will also reliably protect the metal from corrosion. This method can also be used for patination of bronze items.
Patination of silver coins
- Applying a new patina to silver-containing metal is quite simple. To do this, you will need ammonia or ordinary ammonia. Send the coin to the freezer for twenty minutes or half an hour. After the allotted time, carefully take the money by the edge with thin tweezers and bring it to an open bottle of ammonia. A miracle will literally happen before your eyes: the coin will become grayish due to the emerging patina. Stop working on the instance as soon as it takes on the desired shade.
- An even simpler way is to use ... a boiled chicken egg. After it is hard-boiled, the egg is cut and placed in a container with a fairly narrow neck. The coin is also sent there. Under the influence of hydrogen sulfide, silver changes color, becoming covered with a patina. This method is good in that it achieves the most uniform coverage, without stains from tweezers.
Patination of coins containing bronze
As mentioned above, to apply a new patina to metal with a bronze content, a method based on sodium hyposulfite is used. In addition, with some haste, ammonia and sulfuric ointment are used. Numismatists advise experimenting with the usual laundry soap, in the gruel from which a coin is placed for 2 weeks.
However, bronze coins are best covered with noble rust in a natural way, under the influence of the sun, wind, and rain. In just one and a half to two years, they will have an even and beautiful brown tint.
So, patina can be created artificially, and, in some cases, this is quite simple to do. However, I would like to warn novice collectors: in professional circles, any interference in appearance a coin is always equated with a flaw and significantly affects the collection value of a copy. It is advisable not to bring your collection to a state where it would require patination from the outside.
Remember that a specialist will always easily, by eye, evaluate whether the real patina protects the metal or the shell was created artificially. So, the original “noble rust” envelops the coins in a rather thick layer, reliably covering chips and scratches. A remake can be scratched with any sharp object.
Over time, copper things lose their color and begin to acquire a dark or green tint. This happens naturally during the oxidation process, but modern designers are actively promoting vintage interior elements, it looks beautiful, sophisticated, expensive.
But in order to achieve a beautiful shade of patina, it is not necessary to wait several years, you can age the product artificially. There are many ways to do this. You can choose for yourself any that will be best suited.
Basic Tools
The use of various methods of aging involves the use of some tools or improvised means. But there are universal items that are used with any method:
- the product itself, carefully crafted;
- thick rubber gloves;
- goggles for eye safety;
- aging agent (vinegar, ammonia, prepared solutions, acetone, ammonia);
- soap or just water for cleaning;
- magnet for checking the composition;
- hot processing (hair dryer or any other heating agent);
- brush;
- special container (bucket, cans, plastic jars);
- means for polishing and polishing (sponge, cloth).
Use of ammonia
Before starting work, you need to process the copper product with a file (a special file for jewelry work) - this preparation helps to clean the thing from dirt and put it in order. To process with ammonia, you will need: the treatment itself, any container with a tight-fitting lid, a cotton pad and a lid the size of it.
A cotton pad should be put into a small cap, thoroughly soaked with ammonia and put together with a copper product in an airtight container. After 10 minutes, you can see how old the copper thing is. When opening the container, do not forget that you can smell a strong smell of alcohol, so it is better to use a protective bandage.
Application of vinegar
In order to age a copper thing with vinegar, you need to carefully prepare it. The preparation process consists of several stages:
- if the copper product is covered with a layer of varnish, then it must be removed. To do this, you must either hold the product in a container with acetone, or carefully brush it with a brush with the same product;
- further, the copper thing must be poured with hot water and rinsed so that the varnish comes off completely;
- if the copper thing does not have any additional coating, then it will be enough just to wash it with soap;
- the aging process cannot be started if the product is not dry enough. To speed up drying, you can use a hair dryer, but before that, make sure that there are no traces of a protective coating left on the copper, otherwise the copper product may catch fire.
After preparatory stage completed, you can start processing with vinegar. The big advantage of this method is that it does not need to work with harmful substances and vinegar is always on hand in the kitchen.
As in the case of acetone, you can either dip the product in vinegar, or apply it on a brush and carefully process the item. Also, if you need to get a green patina, you can add a spoonful of salt to the vinegar. After the desired result is achieved, the copper thing must be washed in warm water and gently dried with a towel.
Aging with a gray tint with sulfuric liver
First you need to cook sulfuric liver. This can be done like this:
- mix sulfur powder and potash in a ratio of 1: 1 in a tin, put the mixture on fire;
- after the mixture began to melt and darken, the sintering process begins;
- after 15 minutes, the tin can be removed from the heat and the mixture allowed to cool slightly.
Now you can start preparing the solution in order to start patination and age the copper thing. Mix 3 g of salt and 3 g of cooled sulfuric liver in 1 liter of water. Mix the solution thoroughly and lower the copper product into it. When copper has acquired the desired gray tint, you can take out the product, then rinse with water and dry.
Application of ready-made solution for aging
This method is the fastest, since the tool itself does not need to be prepared independently, it is sold ready-made. Since the aging solution contains substances harmful to the skin, do not forget to wear gloves and goggles.
Brass Black Metal Finish for copper aging, manufacturer - American company Birchwood Casey
Different solutions may have different information about how much to dilute the liquid, but you should always follow the instructions that are indicated on the label of the purchased product.
When the preparatory processes are completed, you can begin to process the copper product. To do this, you need to lower the copper thing several times into the solution at different angles so that the entire surface of the product is covered with the product. It is necessary to ensure that there are no bubbles, because then light spots may remain in their place.
Repeat this procedure until you get the desired color. Overexposure or, conversely, lifting the product out of solution too early is not a problem, since during overexposure it can be processed with a scraper, and if the desired color is not achieved, lower it into the product again. At the end of the process, the copper must be dried and varnished if you want to fix the result.
Use of ammonia
Of all the products presented, ammonia is the most caustic, but it is the best at aging copper and produces a greenish-brown patina. The disadvantage of using this tool is that this gas evaporates, which is why they need to be processed more often than with other substances. To use this method, you will need: ammonia itself without impurities, a sealed plastic bucket, small wooden blocks.
Patination or aging of copper coins
The ammonia application method consists of the following steps:
- put the bars at the bottom of the bucket so that you get a small but stable platform;
- pour ammonia into the bucket, without bringing its level to the upper surface of the platform;
- to put on wooden structure copper product so that it is firmly held on the platform. If it falls from it, then you just need to get it, rinse it with water and place it on the bars again;
- close the bucket tightly and check readiness every hour. The procedure usually takes several hours. When checking the appearance of the desired shade, do not inhale ammonia fumes.
Drying, as in the case of other methods, is an obligatory and final stage of aging. You can also dry it naturally, without using a hair dryer and other hot methods.
It is not worth varnishing the item, as you will have to periodically remove it, because, as mentioned above, ammonia treatment is carried out repeatedly during the use of a copper item.
The use of ammonium sulfide
In order to age copper, you can use the substance of ammonium sulfide, mixing which with other substances can give the product a patina of different shades:
- light brown - in one liter of water, 5 g of a solution of ammonium sulfide 18%, 124 g of sodium dichromate, 15 g of nitrogen acid with a density of 1 g per 1 cm 3, 5 g of hydrochloric acid are mixed. The mixture is applied with a brush to the product, washed off after 5 hours, and after drying, repeat this procedure 2 more times;
- dark brown - 9 g of ammonium persulfate and 50 g of caustic soda are mixed in one liter of water. The solution is heated to 95 degrees. The product is lowered into the solution for 5-25 minutes, depending on the desired color saturation, washed, dried. The procedure is repeated 3 times.
Use of others various substances, which help to age the object and give a patina of different shades:
- golden - 1 g of copper sulfide, 180 g of caustic soda and 180 g of milk sugar are mixed in one liter of water. The solution must be heated for 15 minutes to 90 degrees. After that, the product is also lowered into it for 15 minutes, and then dried.
- golden brown with a raspberry sheen - 50 g of copper sulfate and 5 g of potassium permanganate are mixed in one liter of water. The mixture is heated to 80 degrees, and the product is kept in it until the desired result is obtained.
If you are not an expert in chemistry, then you are better off using ready means for aging copper or in the simplest ways (using vinegar, for example). It will be more difficult for the layman to grasp the need for certain proportions and not make a mistake in creating the desired solution.
If you have experience with chemicals, you can try to apply the prepared solutions first on separate parts of the copper product, so as not to re-patinate with each unsuccessful result.
Solutions containing any hypochlorite should be avoided, since this substance is very difficult to control at home and its careless use will most dangerously affect health.
When using any method, you need to remember your protection: long gloves and goggles must be worn.
To fix the result, you can use wax or paraffin: they are better than varnish removed later, when you need to repeat the procedure. This will be more appropriate if the ammonia method has been chosen for aging.
If there is any doubt about whether the item is copper or not, you need to take it to an antique shop. The specialist will quickly be able to determine what metal the object is made of. You can also check the composition of the product by bringing a magnet to it. If a thing sticks to a magnet, then most likely it is not copper, but just a copper coating deposited on the metal. In this case, it is also possible to age the product, while eliminating rough processing.
Video: Copper patination at home
