How to age coins. Patination of coins. Patination of copper coins with potassium permanganate and copper sulfate
Hello dear readers. In the next article, we will tell you what coin patination is and how to do it. Cleaning and patination of coins are almost always connected with each other. Often, after the cleaning process, we get an unnatural shine of the coin or an unpleasant shade of color. “Now cut off half of the initial price,” forum experts grumble, examining your freshly cleaned copy. To return the coin to its usual form, a means for patinating coins or pointing the patina manually will help. Coin patination methods depend on the metal with which we have to work.
patination theory
The word "patina" seems to us primordially Russian, like "old" or "homeland", but it came to us from the Italian language. It appears due to a chemical reaction that transforms the surface of the coin. On silver or copper, the patina looks beautiful, while the patina on an aluminum coin is a cloudy film, which is why such specimens lose value. Spotted or partial patina also does not add to the charm of the coin. Therefore, the patina that disfigures appearance coins are removed. It should be remembered that patina is part of the coin. If the oxidation processes have affected the deep layers, then after cleaning, instead of a coin, we will get a thin plate with shapeless ruts instead of a pattern. But even well-preserved coins can look unsightly after cleaning. This is especially true of copper coins, which take on a reddish color. However, it is possible to restore the appearance of undisturbed antiquity to the coin. For this, patination is used - the process of inducing an artificial patina.
Availability of patina guidance
It seems to an unprepared collector that in order to restore a patina, one must be almost a medieval alchemist or work in a large chemical laboratory. This is not true! Most types of patina are induced simple ways using available ingredients. Despite the fact that the patination of coins is the application of an additional layer that gives the surface of the specimen a beautiful color, the defects of the coin induced patina won't hide. Dark spots, ruts, nicks, smudges, etc. will remain in place, they will only change color. According to experienced collectors, artificial patina will not add anything to the price of a coin. But the patina, induced by experienced hands, is no different from the natural one, and the coin acquires a very attractive appearance in the eyes of potential buyers. The processes of inducing patina for different metals are fundamentally different. Simply put, there is no universal method. Let's look at some.
Patination of copper coins
There are many ways to put a patina on copper. The method using manganese and copper sulfate is very popular. If there is only a standard package (3 grams) of manganese, then take 10 grams of copper sulfate per half liter of water. If manganese is taken in the amount of five grams, copper sulfate will need 20 grams per liter. The solution is heated to 90 degrees. When the desired temperature is reached, we place the coins in the solution. The temperature should be controlled by heating the solution and periodically turning the coins over. The result: a wash-resistant bright brown patina. Pay attention to the toxicity of vitriol and take the measures required when working with toxic substances.
Fixer (sodium hyposulfite) puts a patina on clean and fat-free coins. We keep the coins in the solution from 10 seconds to half a minute. Removed coins are wiped with a cloth. When the coin dries, patination will give it a bronze color. The easiest way is to heat the coin in the flame of a gas stove burner when the test specimen turns light brown. Copper plating is also a simple option, although less popular. Patination of coins with sulfuric ointment is also not a difficult way. Work must be carried out in water. Rubbed with ointment, the coin gets a patina of dark brown or grayish color. For clarification, after a forty-minute pause, the coin is first polished with a napkin, and then washed with a soapy brush. Experts do not recommend sulfuric ointment, but for experiments with simple methods, it is quite suitable.
Patination of silver coins
Silver is advised to be patinated with ammonia (an ordinary vial of ammonia). For half an hour, the coin is placed in the freezer. Fixing the experimental specimen with tweezers by the edge, hold it from a minute to three over an open bubble. As soon as the coin acquires the desired gray color. Then we wash the coin in water and dry it. For those who don't want to mess around with ammonia, a simple hard-boiled chicken egg will do. It is cut into pieces and covered with a glass jar along with a coin placed on edge. Patination of coins in this way is fast: the change in color is visible to the eye. However, if the color does not suit you, it will not be easy to wash off the induced patina.
When everything happens by itself
If you put a patina on bronze coins, then you can use methods suitable for silver. But there is a way to patinate bronze coins in a natural way. To do this, bronze coins must be constantly exposed to sunlight. The sun helps to get a beautiful and even patina on bronze in one and a half to two years. Of course, this method cannot be called an express method, but there is no need to wait half a century either. Returning to copper, remember the advice to keep the cleaned coins in a jar of matches. The results are mixed, but you can experiment on inexpensive copies. At home, they try patination with wood. Certain types of wood release tannins, which contribute to the production of "cabinet" patina.
Silver is a beautiful noble metal. Products from it are simply mesmerizing - they shine, shimmer in the light and look like a real work of art. But as soon as you take silver in your hands or put on jewelry from it, a rapid oxidation process begins. The metal tarnishes and loses a fair amount of its appeal.
Therefore, many people prefer to darken silver. On the one hand, such products become similar to antiques covered with a touch of patina. On the other hand, shiny silver with dark patches looks more attractive.
Blackening and oxidation
How to darken silver at home? There are two ways to do this: oxidation and traditional blackening. And the difference between these two methods is enormous.
During oxidation, silver is covered with a thin film of oxides, so the product receives a dark coating. But the coating is short-lived and easily erased. The difference is especially noticeable when cleaning - if you polish oxidized silver, then it becomes covered with a grid of lighter spots.
Blackening is the coating of a metal surface with a mixture of silver, copper and lead sulfides. Such a coating is resistant to abrasion and completely disappears only with prolonged boiling or when exposed to acid.
Blackening on an industrial scale is carried out in various ways. But, as a rule, they all represent the application of a powder from a mixture of silver, copper and lead sulfides to the product. The patina is fixed by the “dry” or “wet method” - in the first case, the product is fired after applying the powder, in the second case, the metals are diluted with water to a creamy state, and after applying the mixture, the silver is heated in a muffle furnace.
If we talk about how you can generally darken silver, then experts distinguish the following methods:
- galvanic - this technology provides for the presence of special equipment, therefore it is not used at home;
- mechanical - using graphite;
- chemical - the most reliable method of blackening.
mechanical method
How to darken silver at home with graphite? This is a fairly simple technology, and its result is due to the same processes that occur with lunar metal over time. That is, particles of dust stick to it and tightly "eat" into the recesses. With the help of graphite, you can simply speed up this process.
For blackening, the products are lubricated with a mixture of graphite powder, iron oxide and turpentine, diluted to a mushy state. Then they wait for complete drying and wipe the silver with a soft cloth. The older the product, and the more uneven its surface, the more noticeable the result will be. But in general, such blackening is less durable than that obtained by a chemical or galvanic method.
Blackening with an egg
How to darken silver at home with an egg? The technique is quite simple and you do not need to buy any additional funds. Everything you need is already in the fridge. So, for blackening with an egg, you must perform the following steps:
- Boil an egg or two if there are a lot of silver jewelry.
- Separate the protein - it can be eaten, since it does not participate in the creation of a noble plaque. All the substances necessary for blackening are concentrated in the yolk.
- The yolks must be placed in an airtight container and crushed.
- Next, you need to place the silver in the same container, but so that the metal does not touch the yolks, otherwise the blackening process will be too fast and uneven. Therefore, decorations must either be hung or laid out on a wire rack, in the most extreme case, isolated with a paper towel.
- Products should be left with yolks in a tightly sealed container for a day. If after 24 hours the result does not look too impressive, then you can leave the silver for another 1-2 days.
- Take out the products and wash them with soap.
- Polish all protrusions with a soft cloth.
Use of iodine
How to blacken silver at home with iodine? When using this substance, the product must first be cleaned. Then apply an iodine solution with a cotton swab or a cotton swab and put the silver to dry best under direct sunlight.
When the metal darkens, it needs to be cleaned with toothpaste - it will replace a mild abrasive. After cleaning, the bulges will shine, and the recesses will remain darkened. If the result is far from perfect, then the procedure must be repeated as many times as necessary.
The disadvantages of this technology are obvious: this blackening method is suitable for embossed products, but is not suitable for jewelry with a smooth surface.
Sulfuric ointment
You can quickly and effectively darken silver with sulfuric ointment. This is a drug that is mainly used to combat scabies pathogens, both in humans and animals. Therefore, it is sold both in a veterinary and in a regular pharmacy.
Sulfur ointment is thick, yellow in color and has a rather unpleasant odor. It must be applied to the product, and then heated to a fluid state with a hair dryer. After the ointment becomes more liquid, it can be more accurately distributed on the surface of the silver. When heated, it will be seen how the metal acquires a rich black-blue or purple color. After the product can be wiped dry, if necessary, the procedure can be repeated.
Also at home, in order to darken silver, they use "sulphurous liver" - a sintered mixture of sulfur and soda, which is thrown into water with silver. But at home, this blackening technique is not recommended, since hydrogen sulfide, a dangerous gas with an unpleasant odor, will be released in the process.
How to clean blackened silver?
Applying a dark coating is much easier than removing it later. In order to get rid of blackening, you will have to make a lot of efforts, and most likely, you will turn to specialists for help.
But if you need to clean blackened silver, while maintaining a noble dark coating, then such a procedure will require special care. First of all, you need to abandon the brushes, and use only soft cloths for polishing. So the relief will remain darkened, and the bulges will be shiny. You can use toothpaste as an abrasive. The blackened product must not be boiled or cleaned with caustic substances.
And in cases where you give a pated piece of jewelry to a workshop for cleaning, you must warn the jeweler that you need to preserve the noble patina.
Everyone knows that collecting is a rather scrupulous occupation. Absolutely every numismatist can spend weeks looking for the coin he needs in a suitable condition, but unfortunately a small number of old coins are in a satisfactory condition.
And so you often have to buy coins that do not meet your expectations. Because of this problem, the numismatist community has found several methods for giving copper coins the desired appearance.
When and why is patination of copper coins necessary?
There are several reasons why numismatists patinate coins:
- The coin was bought or found in a bad condition. For example, now there are quite a lot of copper kopecks on the market, which were dug up with a metal detector. In this case, centers of corrosion are formed on the “copper”, which must be eliminated. There are cases where the find already has a beautiful patina, but this is rather an exception. It strongly depends on the soil and the place where it was found.
- The second reason for the manipulations is the ignorance of the previous owners of the value of the preserved patina. Most often, it is erased in an attempt to give shine. Or it is thrown into acid, after which its color turns yellow-orange.
- Increase in cost. Undoubtedly, a copper coin in a brown patina will interest the buyer more than an identical copy covered with green spots. At first glance, their safety is the same, but people are willing to overpay a little for the appearance.
Patination is the artificial aging of objects. It is carried out by a chemical reaction, during which a film or plaque is formed.
Today we will tell you in detail about better ways and instructions for applying patina. Do not think that this is a simple task, in the process you need to observe the proportions of substances, otherwise you can lose a rare coin forever.
Recipes for patinating copper coins at home
We will give you the best recipes for self-patination of coins. If you want to achieve a decent result, then do not be lazy to pre-prepare the material.
A copper penny of the Russian Empire in need of cleaning
These words mean cleaning from oxides and various metal growths.
We advise you to start this procedure on inexpensive specimens in order to practice a little. Don't be upset if something doesn't work out for you. The first time it is difficult to achieve the desired result. All comes with experience.
Sulfuric ointment
Sulfur patination is not the best option for a collector because it will easily rub off even with a sponge.
The color, too, cannot be called natural, it will give off a gray tint.
The technology is quite simple and is carried out in three stages:
- Apply sulfuric ointment to a coin immersed in warm water,
- Wait until she gets the right color.
- Wash off any remaining ointment with soapy water.
Warm water is needed for the reaction to proceed slowly. This will help you to more accurately match the color tone.
The use of sulfur ointment on the example of a copper cent in 2009
The only advantage of using sulfuric ointment is the simplicity and speed of the appearance of patina.
Manganese and copper sulfate
If you want the coin to be covered with a strong uniform patina, then the method using manganese and copper sulphate is best suited. It will give the most natural color to the product. Instructions for preparing the solution are not difficult.
A good example of the use of a solution of manganese and vitriol
In total, 3-4 grams of manganese, 10 grams of copper sulfate and half a liter of water heated to 90 degrees Celsius will be required. When patinating, do not forget to turn the coin over, otherwise the sides will differ in color.
Try to keep the proportions, otherwise you may not only not improve, but also lose the relief forever.
Also keep an eye on maintaining the temperature, so do not forget to heat the solution from time to time. There is no exact time frame for the stay of the coin in solution, you just need to wait until the patina evenly lies.
Conclusion
After reading our article, you can give a beautiful old look to copper coins yourself.
The main thing is not to be afraid to experiment and try each of the methods described above.
So you can compare the results yourself. Remember that the methods described are only suitable for copper coins, other alloys require different solutions accordingly.
Video: Patination or aging of copper coins
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. It has a variety of 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 easier way is to use ... 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 ordinary laundry soap, in which a coin is placed in a slurry 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 with the appearance of a coin is always equated with a disadvantage and significantly affects the collector's value of the specimen. 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.
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 it a special charm. 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;
- rubber 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 an aqueous solution of 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. At this method There are two implementation options:
- Pour ammonia into a small container, for example, into a cork from a plastic bottle, place it in a plastic container along with a 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 is easy to find in stores selling fertilizers. 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. In conclusion, the coin should be washed in soapy and clean water, dried 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.
