Patination of bronze watches at home - the best ways to develop and remove patina

Bronze watches are in great demand. This is largely due to the ability of bronze to become covered with a unique patina , acquiring a noble appearance characteristic of antique products. From a chemical point of view, patina is an oxide film that forms when reactive metals come into contact with anions (such as oxygen and chloride ions). The process of natural patination occurs slowly, but like most chemical reactions, the formation of patina can be accelerated by increasing the concentration of reagents, introducing catalysts and increasing the temperature. In this article, we'll look at some ways to artificially create (and remove) patina at home, using the Bell & Ross Diver Bronze BR 03-92 square diver as an example. A review article on this model can be read on our website.

Before you start experimenting, you need to understand what copper, brass and bronze are. Copper is a metal element, and brass and bronze are metal alloys based on it. Brass is an alloy of copper and zinc. Bronze is an alloy of copper and tin. Due to the different composition of these alloys, the patina formed on them also differs in appearance.

Patination of brass at home

I have long been planning to prepare an interesting composition for chemicals.
colors of brass, a bottle of which one of our comrades once filled me with. This composition is famous for its ease of preparation in ordinary apartment conditions and the availability/cheapness of components that our “mad printer” has not yet declared precursors. And also because it colors brass products in a deep black color, after which it is easy to mistake them for oxidized steel. The coating is no less durable. If, of course, you follow the technical process. And here is just the right case - the brass barrel of a Cybergun Sig Sauer with a shiny muzzle. I purchased the components and tried them out. Happened. I am sharing with the community a detailed description of how and what to do.

We will need the following components:

1. Copper sulfate. These are greenish-blue crystals, usually packaged in bags. You can buy it at hardware stores and gardening stores. 2. Baking soda. It seems that you can use calcined one, but I haven’t tried it, and it’s easier to buy drinking water; it’s available in any grocery store. 3. Ammonia, also known as ammonia: sold in pharmacies without a prescription, in 25 ml glass vials, under the racial name “Ammonia”. 4. Ordinary water. 5. Glass, ceramic or plastic containers, as well as a small frying pan or the like, which you don’t mind, or a flat stainless steel tray, or something similar.

The following proportions of substances will be required to prepare approximately 60-70 ml. composition. At least that's what I did. For those who don't happen to know, 1 milliliter of liquid is 1 gram.

We take two containers and pour 50 ml into each. boiled or distilled water. It can be warm or even hot, but preferably not below room temperature. In one container we prepare a saturated solution of copper sulfate, in another - a saturated solution of soda. This means that we pour the substance into the container, adding it in small portions and stirring thoroughly until we see that it stops dissolving in water. Copper sulfate dissolves rather poorly; Undissolved crystals must be discarded by filtering the solution or carefully draining the sediment into another container. The vitriol crystals can first be ground in a mortar to dissolve faster.

As a result, we get two liquids - translucent bright blue with a greenish tint (vitriol), and cloudy whitish (soda).

Now we take a third container, pour the copper sulfate solution into it and carefully, in small portions, pour the soda solution into it. You can’t drink the entire volume at once - a violent reaction occurs, the composition foams a lot. Poured in - wait and smoke: the foaming process should stop completely, i.e. bubbles should stop releasing (this is about 30-40 minutes).

At the end of the reaction, we obtain an opaque composition of bright turquoise color, quite thick, reminiscent of whipped sour cream in density. We keep it for some more time, during which its particles are cut off from excess water; Carefully drain the water from the surface. And pour the composition itself from the container onto a pre-prepared frying pan or the like.

Then there are two ways: wait until the water has completely evaporated, or speed up the process. I took the second route, placing a flat stainless steel container on a gas stove, and over low heat, stirring with a teaspoon, evaporated the water. You can’t heat it too much, the composition will bubble a lot, burn and turn black, this is of no use.

As a result of evaporation, we obtain a rather densely compacted greenish powder, the shade of which is warmer, rather light green, rather than turquoise, like the original composition.

After waiting for the container to cool, scrape the powder from its bottom: for example, with a small spatula. Next, we place it in a ceramic mortar and grind it with a pestle, turning it into fine dust. We keep it warm for some time, stirring: this is so that the last remnants of moisture evaporate from the powder. We take one more, final container, fill it with 50 ml. ammonia (this is 2 pharmaceutical bottles), and pour the powder into the alcohol. Mix thoroughly.

Note - ammonia is a highly volatile liquid, smelly, and its vapors are very active; if accidentally inhaled deeply, you can have a hellish failure in your breathing and nosebleeds, so be careful.

After dissolving the powder in ammonia, we obtain a transparent liquid of a very beautiful dark blue color with a strong shade of turquoise, which, when uncorked, emits strong ammonia vapors - this is the ready-made composition for blackening brass. It should be stored in a tightly closed container with the narrowest possible neck, for example in a suitable medicine bottle, just in case, away from sunlight. According to my estimates, he is good for use within approx. 2-3 years. After 6 years, the remainder of the composition that was once cast for me has not lost its beautiful color, but the ammonia has completely worn out and it has stopped working.

The process of painting brass parts in this composition is very simple. A clean part, freed from patina (if any), must be thoroughly washed with soap and degreased, and according to my observations, it is better with gasoline than acetone, and then immersed in the composition for a period of 10 minutes to half an hour. Then remove and inspect: if it is painted unevenly, without removing the resulting coating, repeat the degreasing process and immerse it again in the composition for the same period. Next, remove, rinse with water and wipe with gasoline/acetone, and coat with machine or gun oil.

If all conditions are met, we obtain a black, sometimes with a bluish tint, very abrasion-resistant coating.

A piece of brass capillary. In progress:

Sig Sauer barrel:

Brass leads, blackened according to the described method:

And a few more simple recipes can be found here:

How to darken copper at home - Metals, equipment, instructions

Copper plating is the process of applying a copper layer to the surface using an electroplating method.

The copper layer gives the product visual appeal, which allows the use of copper electroplating in design projects. It also gives the metal high electrical conductivity, which allows the product to be subjected to further surface treatment.

Copper plating can be used as the main process to create a surface layer, and also as an intermediate operation for the subsequent application of another metal layer. This method includes, for example, the process of silvering, chrome plating or nickel plating.

Copper plating can be done at home. This makes it possible to solve many everyday problems.

Copper plating by immersion

The process is carried out following the following steps:

1. The oxide film is removed from the surface of the steel part using sandpaper and a brush, and then the part is washed and degreased with soda and a final rinse with water.
2. Two copper plates are placed in a glass jar, connected to copper conductors, which serve as the anode. To do this, they are connected together and connected to the positive terminal of the device used as a current source.
3. The workpiece is suspended freely between the plates. The negative pole of the terminal is connected to it.
4. A tester with a rheostat is built into the circuit to regulate the current.
5. An electrolyte solution is prepared, which usually includes copper sulfate - 20 grams, acid (hydrochloric or sulfuric) - from 2 to 3 ml, dissolved in 100 ml (preferably distilled) water.
6. The prepared solution is poured into a prepared glass jar. It should completely cover the electrodes placed in the jar.
7. The electrodes are connected to a current source. Using a rheostat, the current is set (10-15 mA should be per 1 cm2 of part area).
8. After 20-30 minutes, the current is turned off, and the copper-plated part is removed from the container.

:

Copper plating without immersion in electrolyte solution

This method is used not only for steel products, but also for aluminum and zinc products. The process goes like this:

1. A stranded copper wire is taken, the insulating coating is removed from one end, and the copper wires are given the appearance of a kind of brush. For convenient use, the “brush” is attached to a handle-holder (you can take a wooden stick).
2. The other end of the wire without a brush is connected to the positive terminal of the voltage source being used.
3. An electrolyte solution is prepared based on concentrated copper sulfate with the addition of a small amount of acid. It is poured into a wide container, necessary for convenient dipping of the brush.
4. The prepared metal part, cleaned of the oxide film and degreased, is placed in an empty bath and connected to the negative terminal.
5. The brush is moistened with the prepared solution and moved along the surface of the plate without touching it.
6. Once the required copper layer has been achieved, the process ends and the part is washed and dried.

There should always be a layer of electrolyte solution between the surface of the part and the improvised copper brush, so the brush must be dipped in the electrolyte constantly.

Copper plating of aluminum with copper sulfate

Copper coating is a great way to update aluminum cutlery and other aluminum products used in the home.

Copper plating of aluminum with copper sulfate can be done independently. A simplified option to demonstrate the process is to coat a simple shaped aluminum plate with copper.

You can practice with this example. The process goes like this:

1. The surface of the record must first be cleaned and then degreased.

2. Then you need to apply a little concentrated solution of copper sulfate (copper sulfate) to it.

3. The next step is to connect the wire connected to the negative pole to the aluminum plate. You can connect the wire to the plate using a regular clamp.

4. A positive charge is applied to a device consisting of bare copper wire with a diameter of 1 to 1.5 mm, the end of which is distributed between the bristles of the toothbrush.

During operation, this end of the wire should not touch the surface of the aluminum plate.

5. Having dipped the bristles in a solution of copper sulfate, begin to move the brush in the place prepared for coating with copper. In this case, there is no need to close the circuit by touching the surface of the aluminum plate with the end of the copper wire.

6. Copper plating of the surface immediately becomes visually noticeable. In order for the layer to be of high quality, there is no need to rush to complete the process.

7. After completing the work, the copper layer must be leveled by additional cleaning, removing the remaining copper sulfate and wiping the surface with alcohol.

Galvanoplasty at home

Galvanoplasty is the process of electrochemical action on a product in order to give it the required shape by depositing metal on the surface.

Typically this technology is used for metal coating of non-metallic products. It is widely used in jewelry and the design of household items.

The coating of the work product must have electrically conductive properties. In the absence of such a layer, the object is first coated with graphite or bronze.

Electroplating at home is especially popular among craftsmen. To create the desired shape, a cast is made from the copy. For this purpose, easily melting metal, graphite and gypsum are used.

:

After the mold is made, the object is plated using an electrolyte.

Rules and methods for patination of brass

Many things and materials lose their attractiveness when they age, but this does not apply to metals and alloys made from them. Patina, or a coating of oxides, gives metal objects high cost and value. It is for this reason that elements made of aged metal can be found in a stylized interior. Many people wonder how to patina brass at home. In fact, this is not difficult to do, the main thing is to stock up on the necessary equipment and adhere to the rules for performing such work.

Patination: what is it?

In order to find out the essence of patination, you should learn about the characteristics of an alloy such as brass. The main part of its composition is copper, and the brass alloy is represented by zinc. Zinc can also be added to the alloy. When interacting with air and certain chemicals present in the air, many metals and their alloys begin to become covered with oxides and oxides, which look like a brown-red or green coating. This coating is called patina; it is formed during the oxidation process of the metal. The process of patina formation is called oxidation.

Many people believe that patination is the same as oxidation. In fact, this is not true, because oxidation is a natural process, while metal patination is artificial aging. During the patination process, the metal or alloy changes its color and takes on an aged appearance.

Do-it-yourself patination (blackening, aging) of copper, brass and bronze

Patination of copper, as well as other methods of its decorative processing (including at home), can make products made from this metal more attractive and give them a touch of noble antiquity. Items made not only from copper, but also from its alloys such as bronze and brass can be subjected to this treatment.

Using various methods of patination of copper alloys, you can achieve completely different shades

Patination and oxidation

The surface of many metals (and copper is one of them), when interacting with the surrounding air and various chemicals, begins to become covered with a thin layer of oxides and oxides.

This process, which also leads to a change in the color of the metal surface, is called oxidation.

For the most part, the process of metal oxidation occurs naturally, but people have learned to cause it artificially, in industrial or home conditions, which is done to give the product an aged look.

Oxidation should not be confused with patination, a process whose essence lies in the fact that a thin layer of sulfur or chloride compounds is formed on the surface of the metal when interacting with various chemical elements. Patination, which, like oxidation, is accompanied by a change in the color of copper and bronze, can also be performed artificially using special compounds.

Copper aging occurs naturally over time or immediately when the surface is treated with any preparations.

If under natural conditions the process of oxidation and patination of copper or bronze can take years, then when using special solutions, patination occurs in a very short period of time.

The surface of a product placed in such a solution literally changes its color before our eyes, acquiring a touch of noble antiquity.

Using various chemical compositions, you can perform such procedures as blackening of copper, patination of objects made of copper and bronze, and blackening of brass in production and even at home.

Preparation for processing

Having decided to perform patination or oxidation, you should not only carefully study the question of how to age brass, bronze or blacken copper, but also provide the necessary safety measures.

The vast majority of chemical compounds that are used to carry out such procedures are very toxic and emit vapors that pose a significant danger to human health.

Therefore, to store such substances both in industrial and at home conditions, you should use vessels with well-ground stoppers, which will prevent toxic vapors from entering the surrounding air.

Keep chemicals out of the reach of children

The procedure itself, carried out to change the color of the surface of a product under the influence of chemicals on it, should be performed in a special cabinet to which exhaust ventilation is connected.

It should be borne in mind that the doors of such a cabinet should be slightly open during the process of oxidation or patination, which will ensure effective extraction of harmful vapors from its interior.

Products made of copper, brass and bronze should be thoroughly cleaned, degreased and washed in warm water before patination. After the patination or oxidation procedure itself, the treated objects are also washed and placed in sawdust to dry.

Using sawdust is a more gentle drying method, since performing such a procedure with a fabric material can damage the thin film of the formed patina, which has not yet been fixed with varnish.

In addition, using fabric after patination, it is almost impossible to efficiently remove moisture from the recesses on relief surfaces, and sawdust can easily be pulled out.

The varnished surface can be polished with a felt pad.

Changes in color of copper and its alloys from gray to black

The grey, dark gray or black color of copper and its alloys makes the appearance of the product more attractive and presentable.

To obtain these colors, the degree of saturation of which can be adjusted, you need the “liver of sulfur” composition that has been used for decades.

It got its name due to the fact that during the cooking process it must sinter, that is, turn into a caked mass.

To make such a composition for patination at home, you must perform the following steps:

• one part of powdered sulfur is mixed with two parts of potash;
• the resulting mixture is placed in a tin can, which then must be put on fire;
• After waiting for the powder to melt and start sintering, it is necessary to maintain this process for 15 minutes.

To prepare sulfur liver you will need soda and sulfur

During the sintering process of the powder, a blue-green flame may flare up on its surface, which does not need to be knocked down, since it will not deteriorate the quality characteristics of the sulfur liver.

After sintering is completed and completely cooled, the resulting mass should be crushed to a powder state.

This powder, if placed in a glass jar with a tight-fitting lid, can be stored for a long time.

In order to patina various metal alloys using liver sulfur, several basic methods are used. Method No. 1

This method involves the use of an aqueous solution of liver sulfur. It can be used to change the color of products made from the following materials:

• copper;
• sterling silver;
• bronze and brass.

The colors that can be used to paint the surfaces of products using this method also vary:

• copper and silver - purple, blue (very difficult to obtain), gray, brown-gray, black;
• brass and bronze – soft golden.

Testing the solution on copper, bronze and brass gives different effects

If you did not know before how to age copper and form a durable patina film on the surface of this metal, distinguished by a rich black color, use this method. To implement it, a copper product is placed in a solution consisting of a liter of water and 1–20 grams of liver sulfur powder.

To color copper light gray, the solution is prepared according to a different recipe: 2-3 grams of sodium chloride and liver sulfur are dissolved in 1 liter of water.

A copper product is placed in the resulting solution, the color change of which should be carefully monitored.

After the color of the metal acquires the desired tone, the object to be patinated must be washed with water and dried in sawdust.

The duration of treatment of copper jewelry with a solution depends on the desired blackening effect

Method No. 2

To patina copper, you can also use a solution prepared according to the following recipe: ammonia is added to a saturated aqueous solution of copper sulfate and this is done until the liquid becomes transparent and bright blue. The cleaned and degreased product to be processed is placed in such a solution for several minutes, after which it is removed and subjected to slight heating. After such manipulations, the copper should acquire a rich black color.

Method No. 3

To use this method, which also allows you to qualitatively blacken copper even at home, the object being processed must be cleaned with fine sandpaper.

Do not touch the cleaned surface with your hands to prevent grease stains from forming on it. After preliminary preparation for patination, the object is treated with a solution of platinum chloride or completely immersed in it.

A small amount of hydrochloric acid can be added to such a solution, if it does not cause an acidic reaction.

Method No. 4

A durable oxide film, distinguished by a rich black color, can be formed on the surface of a copper product by immersing it in a composition prepared from nitric acid and copper metal. To make the color change of the copper part more intense, this solution can be further heated.

Getting a patina of other colors

To form an oxide film of a different color on copper, you can even use one of the following methods at home.

Red-brown

To obtain a red-brown oxide film, the copper product is placed for several minutes in a composition prepared from one part of copper sulfate, one part of zinc chloride and two parts of water.

Using the example of one part, you can see how the shade changes depending on the duration of stay in the solution

Range from light brown to black

To obtain such a patina, a copper object must be placed in a solution consisting of one liter of water and 20 grams of ammonium sulfide. By changing the heating temperature of the processed product before patination, you can adjust the intensity of coloring.

Light brown

To give the surface of a copper product a light brown color, it is necessary to treat it with a mixture of sodium chromium (124 g/liter), nitric (15.5 g/liter) and hydrochloric (4.65 g/liter) acids, 18% ammonium sulfide ( 3–5 g/liter). This solution is applied with a brush and left for four to five hours.

Cover the surfaces of the part until you achieve the desired shade

Range from dark to warm brown

To obtain a surface of this color, the copper part is placed in a hot solution for 5–25 minutes (90–95°

), which contains ammonium persulfate (9.25 g/liter) and caustic soda (50 g/liter). The procedure is repeated 2-3 times to achieve the desired effect.

Range from olive to brown

For patination, a copper product is placed for 10–15 minutes in a heated aqueous solution of berthollet salt (50–70 g/l), copper nitrate (40–50 g/l) and ammonium chloride (80–100 g/l).

Noble white-green

The most popular method of creating a green patina is to immerse a copper object in a composition prepared from water (1 liter), copper sulfate (50 g) and potassium permanganate (5 g).

There are many more methods that allow you to create a patina of various shades of green, brown-black, golden, golden brown with crimson tarnish and others.

How to age an alloy?

To apply patina to metal with your own hands, it is important to know not only how to age brass, but also how to work with the substances and tools used. First of all, you should take care to comply with personal safety rules. The thing is that the patination agent and its analogues contain chemicals that can cause irreparable harm to human health. Therefore, during work, hands and eyes must be protected from accidental contact with the skin (mucous membranes) of aggressive substances. It is necessary to organize work in a well-ventilated room.

Work on a metal object begins by preparing it for patination. First of all, the surface of the product should be degreased, and this can be done using acetone - just apply a small amount of this product to a cotton pad and thoroughly wipe the product with it. Then the brass product should be washed in running water and soap and dried.

A metal object can be patinated with a composition that is popularly called “sulfur liver”. It's easy to prepare:

1. Take 1 part of powdered sulfur and mix it with two parts of potash.
2. The resulting mass is placed in a glass container, which is then placed on low heat.
3. The powder should melt and sinter. As soon as this happens, you should count 15 minutes and only after they have expired, turn off the fire.
4. As soon as the mass is sintered, it should be crushed to the consistency of a powder. Store the powder in a jar with a lid.

There are several effective methods for aging brass using sulfur liver.

1. Take a liter of water and add 20 grams of powder to it. A brass object is dipped into the prepared solution and watch how the product changes color. After this treatment, the brass will turn a soft golden hue.
2. To make the alloy acquire a light gray tint, you need to take a liter of water and add 3 grams of liver sulfur and sodium chloride to it. The coloring of a brass product must be carefully monitored, and as soon as the desired effect is achieved, the object must be removed from the solution and rinsed with water.
3. Ammonia is gradually added to a concentrated solution of copper sulfate and wait until the solution acquires a bright blue hue. The cleaned object is immersed in such a solution for several minutes, after which it is taken out and heated a little. After this treatment, the product will acquire a brown tint. This method is also suitable for aging copper.
4. To age copper or brass, you will need sandpaper, which must be used to carefully treat the surface of the product. After sanding, you can apply a chloride patina solution to the product. You can also dip a product that needs patination into this solution.
5. To blacken brass, you can use a solution consisting of copper metal and nitric acid.
6. To obtain an olive-colored patina, you should prepare a solution consisting of Berthollet salt, ammonium chloride and copper nitrate. The solution should be heated and the brass product should be dipped into it for 15 minutes.
7. To obtain a golden-colored patina, you should treat a brass product with a solution consisting of 180 grams of milk sugar, 0.6 grams of copper sulfide and 180 grams of alkali. The solution is heated to 90 degrees, after which the brass product is dipped into it for 15 minutes.
8. To give brass a dark gray color, you need to use antimony. This substance should be applied to the surface of the product and rubbed with a stiff brush. Once the desired shade has been created, the product should be thoroughly washed and dried by placing it in sawdust.
9. You can also apply nitric acid to the surface of a brass product (to do this, use a cotton swab soaked in acid).

The recipes described for the products used to patina brass can also be applied to silver and pure copper.

Artificial patination

Next, we will test in practice and demonstrate the results of popular bronze patination recipes on the Internet, and also, out of curiosity, we will try something new. Some of these methods give the bronze a subtle, subtle patina, while others, more aggressive, produce distinct brown or green tones. After evaluating the results, you can achieve the desired look of your bronze watch without having to do all the experiments yourself, through trial and error.

Baking soda with vinegar

Baking soda and vinegar is a method that is used in households, such as cleaning plumbing fixtures. Such substances individually have excellent cleansing properties, but when they come into contact, a powerful “fizzy” reaction occurs, releasing carbon dioxide, which decomposes into water, salt and carbon dioxide. During this process, carbon dioxide can dissolve even significant contaminants. We tried to use the resulting solution as a cleaning agent. However, instead of cleaning, the bronze suddenly darkened.

The watch is placed in the sediment solution from the reaction of baking soda with vinegar

The result is a dark patina.

With the addition of vinegar, the cleaning properties of the solution improved, but for some unknown reason this showed up mainly on the bezel.

After adding more vinegar to the solution

Close-up: Patina has not been removed from the sides of the bezel and case

Boiled egg

This is probably the most famous way to patina bronze. You need to hard boil a chicken egg, cool it a little warmer than room temperature, peel it and crush it into small pieces, and then put it in a plastic bag next to the watch (the watch should not come into contact with the egg). The interaction of hydrogen sulfide released by a boiled egg with copper, an integral part of the bronze alloy, leads to the formation of copper sulfide, a black substance.

After 15 minutes, the bronze develops a light layer similar to the natural patina after two weeks of wearing the watch. After another hour, the patina turns dark brown.

A watch and a boiled egg are placed in a plastic bag

After 15 minutes of exposure

In detail: after 15 minutes of exposure

After 1 hour of exposure

In detail: after 1 hour of exposure

Vinegar

No, you heard right. As mentioned above, vinegar is an effective cleaning agent for removing patina. The trick is that vinegar can also be an accelerator if you expose the watch to its vapor rather than the liquid itself. It's all about oxygen, without which oxidation is impossible. That is why vinegar liquid cleanses, and vinegar vapors, mixing with air, on the contrary, accelerate the formation of patina.

Place the watch in a plate or glass on some kind of stand, and pour a little vinegar liquid into the bottom of the container. Vinegar gives off a not very pleasant pungent odor, so it is better to close the container. The result is the iconic green patina. The copper component of the alloy interacts with water, oxygen, carbon dioxide and hydrogen ions in often unpredictable ways, forming various shades of green and blue.

Beginning of the experiment: the clock is set with the dial up

30 minutes later a yellowish tint appears on the watch case

Green deposits have formed on the back of the case

Continuation of the experiment: the watch is turned upside down, and a little vinegar is added to the container

An hour later

The deposits revealed a previously undetectable fingerprint

Methods and means for blackening brass

Blackening of brass at home can be done using the following methods:

1. Ammonia is added to the aqueous solution of copper sulfate until the liquid becomes clear. Place the brass product in the resulting solution and leave for several minutes. Then take it out and warm it up slightly. A black film should appear on top of the product.
2. Thoroughly clean the brass product with sandpaper. After this, you do not need to touch the prepared surface so that no greasy marks remain. Soak for several minutes in a solution of platinum chloride. Then remove and leave in the air.
3. Prepare a composition of nitric acid and copper metal. Warm it up a little and place the brass product in the resulting mixture.

Means for blackening brass
There are many different means for blackening brass. But not all of them can be used at home. After all, some necessary substances are not available for free sale.

Artificial copper color

In addition to the methods described above, there are other methods for patination and oxidation of copper, which make it possible to give the material the following colors and shades:

What is made from artificial copper?

• brown-gray - when immersed in a solution of sulfur liver;
• dark gray - when heating the product in a mixture of liver sulfur solution and ammonia;
• brown-black - occurs under the influence of platinum chloride (if the result is not satisfactory, you can add hydrochloric acid);
• black - as a result of exposure to ammonium sulfur diluted in water;
• green - from the application of low concentrations of copper nitrate mixed with table salt, or from oleic acid;
• golden - from placing in a heated solution of copper sulfide, caustic soda and milk sugar.

The use of each method gives its own result and differs not only in the color of the patina, but also in the duration of preservation of the coating. Sometimes, to protect the product, varnish is applied, then the blackening does not disappear at all over time.

Blackening brass at home

You can blacken brass yourself using various means. But you must act carefully, strictly following the instructions, so as not to spoil the metal.

Preparation for the procedure

Most products used to blacken brass are toxic and can be harmful to human health. They must be stored in tightly sealed containers to prevent toxic fumes from evaporating.

Patination must be carried out in a cabinet with ventilation. The cabinet doors must be kept slightly open to ensure effective exhaust of vapors during operation.

Before patination, the product must be prepared. To do this, thoroughly clean the work surface from any dirt. First, rinse in warm water and then treat with a degreaser.

After completing the procedure, the product must be washed again and placed on sawdust. They will absorb remaining moisture without damaging the surface of the material. Using sawdust for drying is considered a more gentle method than using fabric for this. After all, mechanical drying can damage a thin layer of patina. In addition, this method does not completely remove moisture.

Uses of potassium sulfide

This is a common method of blackening brass. During it, you can use potassium sulfide in different states of aggregation - liquid, solid, gel. It must first be diluted with water in a ratio of 1:16. If potassium sulfide is used in a solid state, it must first be crushed to a powder, and only then filled with liquid.

Blackening of brass can be done using potassium sulfide

It is also necessary to prepare a soda solution. Sodium carbonate must also be diluted in a ratio of 1:16. First, place the product in a solution of potassium sulfide. Leave for a while and then place in a soda solution. This is necessary in order to stop the reaction.

Patination of copper: preparation for the process, methods

Copper is not a precious metal, but it can also be refined to give it an attractive antique look. For this, copper patination is used, which involves the artificial creation of an oxide film. Some material alloys can also be subject to the process: bronze and brass.

Purposes of using patination

Old copper products that have survived to this day have a natural film of oxides and nitrogens. The image of ancient, valuable things is attached to the patinated material.

Nowadays, artificial darkening is most often used to enhance products for the purpose of profitable sale.

This method makes it possible to give the product a rare look, increasing its exclusivity and, consequently, its value.

Copper patination

Preparing for patination

To carry out any chemical reaction, safety rules must be followed. In the specific case of artificial patination, it is important to remember that the process uses toxic chemical compounds, the released vapors of which are poisonous. For safety reasons, you must follow the rules:

1. Properly store substances necessary for a chemical reaction. Sealed containers should be used to prevent toxic fumes from being released into the air.
2. Carefully prepare the materials themselves: clean copper or its alloys, then degrease and wash in water at above average temperature.
3. Carry out the procedure itself in a safe environment. Most often, a special cabinet with a ventilation hood is used.

After coating, it is also better to follow certain recommendations. The products should be rinsed again in warm water and dried. It is not recommended to wipe with fabric materials, since they can damage the patina layer that has not yet hardened and remove water only on the surface layers. For safe and high-quality drying, sawdust is used in most cases.

Quick ways

At home, patination of copper can be done faster. This process does not require special compounds or special safety precautions. The simplest method is heat treatment.

If you expose a material to fire, it reacts instantly. The longer the firing takes place, the darker the color of the oxide film becomes.

After the procedure, it is better to immerse the material in water so that the effect is fixed, then the product must be treated with varnish.

Another simple way is using eggs. Once cooked and cooled, they need to be cut or mashed into small pieces (with or without shell, it doesn’t matter).

Then you need to put the crushed products in any sealed container (a saucepan, for example), where the product is placed. Boiled eggs will release sulfur, and within thirty minutes the first result will be visible.

The longer the procedure is carried out, the darker the effect.

Composition with sulfur liver

To implement this method you will need sulfur powder and water. One liter of liquid should contain up to twenty grams of liver sulfur. The longer the product is processed, the darker it becomes. To give a grayish tint, a few grams of sodium chloride are added per liter of water. The film after such processing turns out rich and durable.

Oxidation in ammonia vapor

A 10% ammonia solution will help give copper a brown, olive or even bluish tint. If you are trying to achieve a result with blue flecks, place the product in a solution of table salt before processing.

In this case, oxidation occurs quickly, in ten or fifteen minutes. For a more noble and deep olive color, the item should be kept for six to eight hours in an airtight container with a solution poured into a small bowl.

Copper coin before and after patination

Patination in sawdust

The method helps to achieve shades of black, blue and pink with splashes. First you need to prepare a solution by mixing the ingredients:

• 700 ml water;
• 600 ml of ammonia;
• 16 grams of salt.

The resulting composition then needs to be soaked in the sawdust until it becomes damp (but not wet). Products should be exposed to fumes from chemically saturated sawdust, but not to direct exposure.

The degree of reaction depends on the duration of the procedure, the level of saturation of the impregnation and the proportion of salt and alcohol in the solution. In principle, other materials that absorb moisture can be used to carry out patination using this method.

Electrochemical method

The most difficult method to carry out at home, but it is suitable for those who are looking for an unusual shade. Carrying out requires the use of electricity and a toxic mixture, so safety precautions must be observed!

1. The first step is to prepare the solution: add 60 g of copper sulfate and 90 g of sugar to 300 ml of warm water; separately, dissolve 45 g of caustic soda in the same volume of cold water; then mix both liquids slowly.
2. The second step is to heat the water to 80 degrees and keep the product in it for about a minute.
3. The third step is to apply electricity, for example, using a car battery: “plus” to the copper anode stick and “minus” to the workpiece. Power - from 0.5 to 1.1 watts.

The color turns out to be very different, depending on the feeding force and processing time. If you do not have time to catch the required color, do not worry and continue patination: it occurs cyclically, you can “catch” the desired shade after some time.

In general, it is quite safe to cover a product with patina, although you will end up with a somewhat trivial option. But to achieve an unusual effect, you cannot do without chemicals, so be very careful.

Security measures

When carrying out patination, it is necessary to observe safety precautions. After all, many of the substances used are very toxic and can be harmful to health. Therefore, it is important to follow the following rules:

• Use a specially equipped cabinet for work that has a hood.
• During the procedure, wear a protective suit, gloves, and goggles.
• Avoid contact of used reagents with skin and eyes.
• All containers must be clean for use. Do not use the same uncleaned glassware for multiple experiments.
• When heating test tubes with reagents, the containers must be held so that their necks point away from you.
• All experiments must be carried out above the table.
• Do not leave reagent bottles open as they may tip over.
• All reagents must be labeled to avoid confusion.
• There should be sand in the office to be used in case of fire.

Thus, you can carry out patination yourself. But at the same time you need to act very carefully, observing safety precautions.

Patination (aging) of brass and copper

I wrote an article based on my own experiences with aging brass.

I hope this information will be useful to someone.

Thanks for the tip Nyura! I wasn’t able to answer you in a personal message. ______________ So: In this article I want to share my own experience in aging brass. Brass is an alloy of copper and zinc, so this method will work for copper wire as well. First of all, let's take care of safety precautions. Let's put on rubber gloves and a respirator (I just bandaged my nose and mouth with a towel