OXIDATION OF THE SURFACE OF METAL ELEMENTS
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Dissolve the powder in water.
The presence of sediment at the bottom is quite acceptable and does not affect the result of oxidation.
Apply the compound to the copper piece with a brush.
Do not allow the blackening compound to come into contact with the surface. natural stones and pearls.
This can lead to changes in the structure of the stone.
In no more than a minute, copper and silver are covered with a brownish-violet oxide film.
When the composition is reapplied, the copper surface darkens, even black.
Let's take a break from the process :)
This is how the oxide film turns out if the liver sulfur solution was too weak:
Let's continue... :)
Sand the part in places where the artistic intent requires it.
The scroll on the right is oxidized with sulfur liver and sanded with a Dremel.
Features of storage of the composition:
Composition in granules
Storage conditions: dry and protected from direct sunlight
in a tightly closed container at a temperature not exceeding 25 degrees. WITH.
Shelf life and use: more than 1 year.
Ready aqueous solution
Storage conditions: in a tightly closed container in a cool place (for example, in the refrigerator).
Shelf life and use: no more than 1-2 days.
Natural method
1. Boil 2-4 eggs in boiling water for 15 minutes.
2. Take out boiled eggs from the water and place on a cutting board. Using a spoon, mash the eggs and shells together.
3. Place the crushed eggs in a plastic zip-top bag. The bag must be large enough to contain the product. As alternative option You can take a large airtight container.
4. Place the copper item in a plastic bag and seal it. If you place more than one item in a bag, make sure they are not touching each other so that they oxidize on all sides. Egg yolks are a must because they contain a large number of sulfur that oxidizes copper.
5. 20 minutes later, remove the copper item from the bag using metal tongs. You will notice that the surface of the copper has darkened. If you want a darker patina, leave the piece in the bag overnight.
6. Remove the product from the bag and rinse lightly warm water to wash off the egg.
PATINATION and OXIDATION of copper
To change the color of a reddish metal, they most often use PATINATED liver sulfur and ammonium sulphide or BY OXIDATION nitric acid.
PATINATION sulfur liver
The composition of sulfur liver includes potash and sulfur. Sulfur is flammable and therefore requires careful handling. Its vapors with air form explosive mixtures. Sulfur should be stored in a dry place, isolated from oxidizing agents (sulfuric acid, potassium permanganate, berthollet salt). Doses of potash and sulfur may vary. Most often, 1 part sulfur is mixed with 2 parts potash. Sprinkled together, both powdered substances are thoroughly mixed, placed in a metal vessel with a handle and set to heat. It is recommended to stir the contents of the vessel. Fusion of the reagents occurs within 15-25 minutes. The reaction produces a dark mass of liver sulfur. From high temperature sulfur smolders with blue-green fire. This shouldn't be a cause for concern since patination the properties of sulfur liver will be preserved. The finished hot mass is poured with water, in which the resulting melt dissolves. The water takes on an intense black color.
Pre-treated copper products are dipped into a hot aqueous solution of liver sulfur. If the leaf is large and does not fit into the vessel, it is watered on top with a solution or lubricated with a soft brush.
Copper turns black very quickly. From the interaction of sulfur ions with metal, copper sulfide is formed. This salt is black in color and insoluble in water and dilute acids.
The reaction is faster and PATINATION It will be of better quality if the plate is preheated. In this case, you should not use an open fire, but an electric stove. Then the plate is washed in warm running water and the convex areas are lightly wiped with pumice powder. The color is black in recesses, greyish on inclined surfaces, and shiny red copper on protrusions. An antique imitation is created.
An aqueous solution of liver sulfur can also affect items made of silver or galvanically plated with silver. They are also covered with a black coating.
Oxidation and patination of copper, brass and bronze.
Some chemical reactions lead to the formation of oxides and oxides, i.e., oxygen compounds, on the surface of metals. This process is called oxidation.
Often chemical elements, interacting with a metal or alloy, contribute to the appearance of sulfur or chloride compounds. The process of forming such compounds is called patination.
If you dip a metal product into the prepared solution, it literally changes color before your eyes. A sparkling metal product takes on the appearance of an antique product in a few seconds.
Majority chemical compounds, which are used for patination and oxidation of metals, are toxic and dangerous to humans. Therefore, they need to be stored in vessels with ground-in stoppers, and all work involving the release of toxic and flammable vapors and gases should be carried out in a fume hood. The cabinet doors should be slightly open.
Before changing the color of the metal, it is necessary to carry out some preparatory operations. The item is cleaned and degreased, washed well and dried in sawdust. Metal art objects and coins should never be wiped with a towel. A towel wipes off fragile patina films that are not secured with varnish; moisture remains in the deep reliefs; the fabric gets caught on high protrusions and can bend them. Sawdust quickly and evenly draws water away from the metal surface.
Patina from gray to black
Preparation of sulfur liver:
To prepare sulfur liver, you need to mix one part of powdered sulfur with two parts of potash in a tin can and put on fire. After a few minutes, the powder will melt, darken and begin to sinter, gradually acquiring a dark brown color. (By the way, the sintering of the patination mass gave the name “liver” in the old days - from the words “oven”, “sinter”.)
During sintering, sulfur vapor may ignite with a weak blue-green flame. Do not knock down the flame - it will not deteriorate the quality of the sulfur liver. After about 15 minutes, stop sintering. For long-term storage, crush the sulfur liver into powder and place it in a glass jar with a tight lid.
Method No. 1
Applies to:
Copper, sterling silver, and bronze or brass (light shade). Does not work on nickel silver.
Colors:
On copper and silver there is a range of shades from purple/blue (difficult to obtain) to brown-gray, gray, black. On brass and bronze - only soft golden.
A durable and beautiful patina forms on the surface of copper treated in an aqueous solution of liver sulfur.
When making a solution in 1 liter of water, add 10-20 g of liver sulfur powder. The patina obtained on metal with a solution of sulfur liver is durable and beautiful, deep black in color. But such intense coloring is not always necessary. Sometimes, to give a copper piece an antique look, it is enough to apply a light gray patina. Pour 2-3 g into a liter of water table salt and 2-3 g of liver sulfur. Dip a copper plate into the solution. After the appearance gray rinse the record to the required key clean water and dry.
Method No. 2
To blacken a copper item, prepare a saturated solution of copper sulfate and add to it ammonia until the mixture takes on a bright transparent blue color. The copper item being processed is dipped into this solution for a few minutes, then removed and slightly heated until it turns black.
Method No. 3
The copper item to be blackened is first cleaned with fine sandpaper, after which try not to touch its cleaned surface with your fingers. Then she either plunges into liquid solution platinum chloride, or moistened with it using a brush. This solution, if it does not have acid reaction, slightly acidified with hydrochloric acid.
Method No. 4
A very durable blackening of copper products is obtained by immersing them in a saturated solution of copper metal in nitric acid and then heating it slightly.
Patina red-brown
An aqueous solution of zinc chloride and copper sulfate colors copper red-brown. Mix one part copper sulfate with one part zinc chloride and dilute in two parts water. A few minutes are enough for the copper to acquire a red-brown color. After washing and drying, wipe the metal surface with oil.
Patina from light brown to black
Blackening of the metal is observed when copper is patinated with ammonium sulfide.
20 g of ammonium sulfide is diluted in a liter of water. The product is dipped into the resulting solution or poured on top and wiped with a brush. The work is carried out in a fume hood. Sulfur ions present in an aqueous solution of ammonium sulfide interact with copper ions. Black copper sulfide is formed.
The intensity of the patina on the metal can be of different shades, from light brown to black. The color is adjusted by changing the heating temperature of the plate before patination.
Patina light brown
Gram per liter:
sodium dichromate - 124
nitric acid (density 1.40 gcm3) - 15.5
hydrochloric acid (1.192) - 4.65
Ammonium sulfide 18% solution - 3-5
Apply with a brush immediately after preparation, rinse off after 4-5 hours and repeat after drying 2 times, polish with a dry cloth.
Dark brown to warm black patina
Gram per liter:
ammonium persulfate - 9.35
caustic soda - 50.0
for 5-25 minutes in a bath with a solution heated to 90 -95 degrees. rinse, dry, repeat 2-3 times
Patina from olive to Brown
Gram per liter:
Berthollet salt - 50*70
copper nitrate - 40*50
Ammonium chloride - 80*100
for 10-15 minutes in a bath with a heated solution to 60-70 degrees.
the resulting films have mechanical strength and corrosion resistance
Patina brown-black
Gram per liter:
Ammonium molybdate - 10
ammonia 25% aqueous solution - 7
the solution should be heated to 60 - 70 degrees
Golden patina
Gram per liter:
copper sulfide - 0.6
caustic soda - 180
milk sugar - 180
A solution of alkali and lactose is prepared separately and only then poured together, boiled for 15 minutes and copper sulfide added.
place the product in a heated to 90 gr. solution for 15 minutes.
Patina golden brown with crimson tarnish and moderate shine
After cleaning copper coins, you can create an artificial patina on them by placing 50 g of copper sulfate and 5 g of potassium permanganate per 1 liter of water in a solution, heating it to a temperature of 70-80C and holding it there until desired color.
Green patina
Color in green color The surface of copper, brass or bronze products can be done in various ways.
Method No. 1
Using a sponge, the surface of things is first lubricated with a highly diluted solution of copper nitrate with the addition of a small amount of table salt. Then, when the item dries, it is lubricated in exactly the same way with a solution of 1 part potassium oxalate and 5 parts ammonia in 94 parts weak vinegar. Let it dry again and again lubricate with the first solution; then, after drying, again with a second solution, etc. alternately until the coloring acquires the proper strength.
Before lubricating, the sponge soaked in the solution should be squeezed out firmly so that it is damp, but not wet. After painting the surface, rub the items thoroughly with hard hair brushes, especially in the recesses and crevices. After 8-14 days of work, a brownish-greenish color is obtained.
Method No. 2
Things are rubbed in several stages with cloth soaked in crude oleic acid (a product obtained in stearin factories). On the surface of things, a dark green layer of copper oleic acid is first formed, which, under the influence of oxygen and air moisture, gradually turns into lighter green copper carbonate.
The process is greatly accelerated if oleic acid first leave the copper shavings for quite a long time, and after each lubrication with such an acid, after the lubricant has dried, lightly spray (no more than a few drops!) with an aqueous solution of ammonium carbonate using a spray bottle.
The finished embossed composition can be left in the natural metallic color of the original plaque, but it can also be “aged”, darkened, chemically treated, followed by grinding, polishing, and, if necessary, varnishing.
Before patination, the product can be treated not with acid, but by thoroughly brushing (cleaning) the relief with a metal brush made of steel wire.
Chemical processing of copper
To change the color of this reddish metal, patination with sulfur liver and ammonium sulfide or oxidation with nitric acid is most often used.
Patination with sulfur liver
The composition of sulfur liver includes potash and sulfur. Sulfur is flammable, so it requires careful handling. Its vapors with air form explosive mixtures. Sulfur should be stored in a dry place, isolated from oxidizing agents (sulfuric acid, potassium permanganate, berthollet salt). Doses of potash and sulfur may vary. Most often, 1 part sulfur is mixed with 2 parts potash. Sprinkled together, both powdered substances are thoroughly mixed, placed in a metal vessel with a handle and set to heat. It is recommended to stir the contents of the vessel. Fusion of the reagents occurs within 15-25 minutes. The reaction produces a dark mass of liver sulfur. High temperatures cause sulfur to smolder with a blue-green fire. This should not be a cause for concern, as the patination properties of the liver of sulfur will remain. The finished hot mass is poured with water, in which the resulting melt dissolves. The water takes on an intense black color.
Pre-treated copper products are dipped into a hot aqueous solution of liver sulfur. If the leaf is large and does not fit into the vessel, it is watered on top with a solution or lubricated with a soft brush.
Copper turns black very quickly. From the interaction of sulfur ions with metal, copper sulfide is formed. It is a black salt, insoluble in water and dilute acids.
The reaction proceeds faster and the patination will be better if the plate is preheated. (You should use an electric stove rather than an open fire.) Then the plate is washed in warm running water and the convex areas are lightly wiped with pumice powder. The color is black in recesses, greyish on inclined surfaces, and shiny red copper on protrusions. An antique imitation is created. Pumice powder can be replaced with powders used for cleaning dishes (Pemoxol, Chistol, etc.). You can also use abrasive powder from an emery wheel. You need to drop a drop of oil (machine, household, vegetable, etc.) onto a cloth, dip it into the powder and wipe the protuberances of the embossing. It is convenient to use a large eraser - wrap it in a cloth and apply oil to a wide surface so that the powder sticks. In this case, when wiping the relief, only the raised areas are highlighted, since the eraser does not touch the background recesses.
An aqueous solution of liver sulfur can affect both silver products and products silver-plated by galvanic means. They are also covered with a black coating.
It is recommended to use liver sulfur solution within 24 hours. Sulfur liver can be prepared for future use and consumed in small doses. The melt of sulfur and potash is poured onto a non-hot surface, cooled, and then broken into pieces and stored in a vessel with a ground stopper. Prepare a liver solution at the rate of 5-20 g of powder per liter of water.
Patination with ammonium sulphide
Blackening of the metal is observed when copper is patinated with ammonium sulfide. 20 g of ammonium sulfide is diluted in a liter of water. The product is dipped into the resulting solution or poured on top and wiped with a brush. The work is carried out in a fume hood. Sulfur ions present in an aqueous solution of ammonium sulfide interact with copper ions. Black copper sulfide is formed.
The intensity of the patina on the metal can be of different shades - from light brown to black. Adjust the color by changing the heating temperature of the plate before patination. If you need to clean the product to the natural color of the metal, do this: dip it in a mixture of nitric and sulfuric (10-15%) acids. Sulfuric acid is added to nitric acid to increase the concentration, since it has the property of attracting moisture. When concentrated sulfuric and nitric acids are mixed, a reaction occurs that releases a large amount of heat, and thick-walled vessels may burst, so you should use only thin-walled chemical containers. When a copper plate is dipped into a mixture of acids, the patination film instantly falls off and the black color disappears. The following precautions should be observed when working with concentrated acids:
a) pour them through a funnel under the draft;
b) when diluting concentrated acids, pour the acid in portions into water and mix lightly.
Nitric and sulfuric acids are especially hazardous substances. They cause severe burns. It is recommended to store acids in glass containers away from flammable materials. Children are allowed to work with them only under supervision. If safety regulations are followed, working with chemicals does not pose a threat. Injury cases linked for the most part in violation of these rules.
If drops of concentrated acid do get on exposed areas of the body, you need to quickly wash the burned area with plenty of water (put it under the tap), and then wipe it with a 3% solution of soda or a 5% solution of sodium bicarbonate, or baking soda.
Oxidation of copper with nitric acid
This method is simple and reliable, but requires caution, since the work is carried out with concentrated acid. Using a piece of cotton wool tied to a wooden stick or clamped with tweezers, a layer of concentrated nitric acid is applied to the surface and the plate is heated. As the temperature rises, the color of the surface changes from greenish-blue to black. The metal relief is covered with a uniform blackness. The cooled product is washed under the tap, and then the convex elements of the composition are highlighted for greater expressiveness. To do this, a piece of felt or thick wool is moistened in gasoline, rubbed with GOI paste and pressed several times along the front side of the metal product. Then wipe dry with cloth. It should be remembered that copper salts are poisonous even if the dust is inhaled. Therefore, after work, you need to wash your hands thoroughly.
Patination and oxidation of brass
Brass has a range of shades obtained by chemical treatment, very large: yellow, orange, red, blue, purple, blue, black. Moreover, a variety of colors can be achieved on the surface of one plaque.
In addition to intense, bright, chromatic brass can be patinated in achromatic, light or dark gray and black tones.
Patination with sodium trisulfate and nitric acid
0.5 liters of hot water is poured into an enamel, plastic or nylon bowl and 20-30 g of sodium trisulfate, better known as hyposulfite (fixer for photographic film), is poured into it. If you add a little (about two thimbles) of some acid, for example nitric, to this solution, the smell of sulfur dioxide appears and after a while clear liquid becomes cloudy yellow with a slight green tint from the released sulfur. The duration of the patination solution is very short, only 15 minutes. Brass is dipped into the solution and the surface is observed to darken. Pre-heated in the jet hot water the plate, lowered into the solution, quickly darkens, acquiring grayish-blue or brownish-violet shades, replacing one another.
The patinated plate is removed with tweezers or hands wearing rubber gloves, and, after washing in hot water, the entire plane of the metal is wiped with a brush and sand, as if applying a chemical primer to the background. The plate is then dipped back into the solution to obtain the final color. Observe changes in the color of the plate, slightly tilting the vessel so that metal can be seen from time to time from the opaque solution.
When the desired color is achieved, the product is removed, washed in hot water and, taking pumice powder on wet fingers, very carefully (the film is very fragile) wipe the convex areas, exposing clean metal. Pumice easily removes patina from a wet plate. Wash off the pumice powder with water.
After drying in sawdust, the product seems to be dusted with a cloudy coating. To return the metallic shine to the coinage, it is wiped with sewing oil or coated with colorless varnish. You shouldn't get carried away with varnish. It is not applied to add shine to the embossed relief, but only to lightly fix weak patina coatings.
Patination with a mixture of solutions of sodium triosulfate and lead acetate or lead nitrate
This patination method allows you to get all the rainbow shades on the surface of a brass product: yellow, orange, crimson, purple, blue.
Patination proceeds as follows. 130-150 g of sodium trisulfate are dissolved in one liter of hot water. In another vessel, 35-40 g of lead acetate or lead nitrate are dissolved in the same amount of water. Both solutions are poured into one container. The solution is heated to 80-90°C and a bleached, etched in nitric acid and well washed brass plate is lowered into it. On the surface of the metal, shades quickly change: yellow turns into orange, which in turn gives way to red-crimson, then purple. Then the plate gradually turns blue, twitches with a grayish coating, turns black, and the reaction stops. All of the colors listed appear continuously. The lifetime of each of them is short. Therefore, as soon as the desired color appears on the plate, it should be immediately removed, washed and dried.
If the product is removed from the solution, washed, and then dipped into the solution again, then removed again, washed, and dipped again in the patination mixture, you will get interesting rainbow colors with relatively sharp transition lines. If the product is removed from the solution gradually, the colors will gently transition into each other. You need to know these methods in order to achieve the intended effect.
Change in color of brass under the influence of antimony chloride
Not everyone likes bright colors on metal, and they are not always appropriate. Sometimes the metal just needs to be blackened. For this purpose, minting masters quite widely use antimony chloride. It is applied with a brush to the finished plate and rubbed with a brush or stiff brush. Work with rubber gloves. The plate is painted in a black velvety color. Depending on the concentration of the solution and the duration of treatment, colors from light gray to velvety black are obtained. When the desired color is obtained, the plate is washed well and dried. The film should not be sealed with varnish.
Oxidation with nitric acid
Coated with a layer of acid, the brass plate turns bluish-green as it heats up, as copper nitrate is formed. With a further increase in temperature, copper nitrate decomposes. A black coating appears on the coinage. The product is cooled, thoroughly washed and dried. The oxide film is firmly and securely bonded to the metal.
Depending on the design, the creator of the coinage can stop the reaction at any stage. To maintain the desired shade, it is enough to interrupt the heating and quickly and thoroughly rinse and dry the plate.
Highlight the convex areas in the same way as on copper, i.e. rub them with GOI paste, after moistening a piece of felt with gasoline. The safety rules are the same.
An interesting and practically easy to perform method is the long-known method of silvering copper and its alloys (including brass) with a used fixer, but with a subsequent change in the silver color with a solution of sulfur liver. The tinting process in this way is carried out as follows:
the finished brass coinage is brightened in the usual way (in weak solution sulfuric acid) and washed in running water;
a paste is made from chalk, ground into powder, and used photographic fixative; add a few drops of ammonia to it;
Using a bristle brush (if the relief is high with deep and narrow areas of the background) or a clean cloth, thoroughly rub the surface of the embossing with the paste; the product acquires a silver color;
under running water, wash off the remaining chalk from the coinage and immerse it in a solution of sulfur liver; the product darkens (with slight color tints), taking on the appearance of old silver;
After washing and drying, the patination operations are completed.
Patination and oxidation of metals
OXIDATION OF THE SURFACE OF METAL ELEMENTS
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Dissolve the powder in water.
The presence of sediment at the bottom is quite acceptable and does not affect the result of oxidation.
Apply the compound to the copper piece with a brush.
Do not allow the blackening compound to come into contact with the surface of natural stones and pearls.
This can lead to changes in the structure of the stone.
In no more than a minute, copper and silver are covered with a brownish-violet oxide film.
When the composition is reapplied, the copper surface darkens, even black.
Let's take a break from the process :)
This is how the oxide film turns out if the liver sulfur solution was too weak:
Let's continue... :)
Sand the part in places where the artistic intent requires it.
The scroll on the right is oxidized with sulfur liver and sanded with a Dremel.
Features of storage of the composition:
Composition in granules
Storage conditions: dry and protected from direct sunlight
in a tightly closed container at a temperature not exceeding 25 degrees. WITH.
Shelf life and use: more than 1 year.
Ready aqueous solution
Storage conditions: in a tightly closed container in a cool place (for example, in the refrigerator).
Shelf life and use: no more than 1-2 days.
Natural method
1. Boil 2-4 eggs in boiling water for 15 minutes.
2. Remove the boiled eggs from the water and place on a cutting board. Using a spoon, mash the eggs and shells together.
3. Place the crushed eggs in a plastic zip-top bag. The bag must be large enough to contain the product. Alternatively, use a large, airtight container.
4. Place the copper item in a plastic bag and seal it. If you place more than one item in a bag, make sure they are not touching each other so that they oxidize on all sides. Egg yolks are a must because they contain large amounts of sulfur, which oxidizes copper.
5. 20 minutes later, remove the copper item from the bag using metal tongs. You will notice that the surface of the copper has darkened. If you want a darker patina, leave the piece in the bag overnight.
6. Remove the product from the bag and rinse with slightly warm water to wash off the egg.
PATINATION and OXIDATION of copper
To change the color of a reddish metal, they most often use PATINATED liver sulfur and ammonium sulphide or BY OXIDATION nitric acid.
PATINATION sulfur liver
The composition of sulfur liver includes potash and sulfur. Sulfur is flammable and therefore requires careful handling. Its vapors with air form explosive mixtures. Sulfur should be stored in a dry place, isolated from oxidizing agents (sulfuric acid, potassium permanganate, berthollet salt). Doses of potash and sulfur may vary. Most often, 1 part sulfur is mixed with 2 parts potash. Sprinkled together, both powdered substances are thoroughly mixed, placed in a metal vessel with a handle and set to heat. It is recommended to stir the contents of the vessel. Fusion of the reagents occurs within 15-25 minutes. The reaction produces a dark mass of liver sulfur. High temperatures cause sulfur to smolder with a blue-green fire. This shouldn't be a cause for concern since patination the properties of sulfur liver will be preserved. The finished hot mass is poured with water, in which the resulting melt dissolves. The water takes on an intense black color.
Pre-treated copper products are dipped into a hot aqueous solution of liver sulfur. If the leaf is large and does not fit into the vessel, it is watered on top with a solution or lubricated with a soft brush.
Copper turns black very quickly. From the interaction of sulfur ions with metal, copper sulfide is formed. This salt is black in color and insoluble in water and dilute acids.
The reaction is faster and PATINATION It will be of better quality if the plate is preheated. In this case, you should not use an open fire, but an electric stove. Then the plate is washed in warm running water and the convex areas are lightly wiped with pumice powder. The color is black in recesses, greyish on inclined surfaces, and shiny red copper on protrusions. An antique imitation is created.
An aqueous solution of liver sulfur can also affect items made of silver or galvanically plated with silver. They are also covered with a black coating.
Oxidation and patination of copper, brass and bronze.
Some chemical reactions lead to the formation of oxides and oxides, i.e., oxygen compounds, on the surface of metals. This process is called oxidation.
Often, chemical elements, interacting with a metal or alloy, contribute to the appearance of sulfur or chloride compounds. The process of forming such compounds is called patination.
If you dip a metal product into the prepared solution, it literally changes color before your eyes. A sparkling metal product takes on the appearance of an antique product in a few seconds.
Most chemical compounds that are used for patination and oxidation of metals are toxic and dangerous to humans. Therefore, they need to be stored in vessels with ground-in stoppers, and all work involving the release of toxic and flammable vapors and gases should be carried out in a fume hood. The cabinet doors should be slightly open.
Before changing the color of the metal, it is necessary to carry out some preparatory operations. The item is cleaned and degreased, washed well and dried in sawdust. Metal art objects and coins should never be wiped with a towel. A towel wipes off fragile patina films that are not secured with varnish; moisture remains in the deep reliefs; the fabric gets caught on high protrusions and can bend them. Sawdust quickly and evenly draws water away from the metal surface.
Patina from gray to black
Preparation of sulfur liver:
To prepare sulfur liver, you need to mix one part of powdered sulfur with two parts of potash in a tin can and put on fire. After a few minutes, the powder will melt, darken and begin to sinter, gradually acquiring a dark brown color. (By the way, the sintering of the patination mass gave the name “liver” in the old days - from the words “oven”, “sinter”.)
During sintering, sulfur vapor may ignite with a weak blue-green flame. Do not knock down the flame - it will not deteriorate the quality of the sulfur liver. After about 15 minutes, stop sintering. For long-term storage, crush the sulfur liver into powder and place it in a glass jar with a tight lid.
Method No. 1
Applies to:
Copper, sterling silver, and bronze or brass (light shade). Does not work on nickel silver.
Colors:
On copper and silver there is a range of shades from purple/blue (difficult to obtain) to brown-gray, gray, black. On brass and bronze - only soft golden.
A durable and beautiful patina forms on the surface of copper treated in an aqueous solution of liver sulfur.
When making a solution in 1 liter of water, add 10-20 g of liver sulfur powder. The patina obtained on metal with a solution of sulfur liver is durable and beautiful, deep black in color. But such intense coloring is not always necessary. Sometimes, to give a copper piece an antique look, it is enough to apply a light gray patina. Pour 2-3 g of table salt and 2-3 g of sulfur liver into a liter of water. Dip a copper plate into the solution. After the required gray color appears, rinse the plate with clean water and dry.
Method No. 2
To blacken a copper item, prepare a saturated solution of copper sulfate, add ammonia to it until the mixture takes on a bright transparent blue color. The copper item being processed is dipped into this solution for a few minutes, then removed and slightly heated until it turns black.
Method No. 3
The copper item to be blackened is first cleaned with fine sandpaper, after which try not to touch its cleaned surface with your fingers. It is then either immersed in a liquid solution of platinum chloride or moistened with it using a brush. This solution, if it does not have an acidic reaction, is slightly acidified with hydrochloric acid.
Method No. 4
A very durable blackening of copper products is obtained by immersing them in a saturated solution of copper metal in nitric acid and then heating it slightly.
Patina red-brown
An aqueous solution of zinc chloride and copper sulfate colors copper red-brown. Mix one part copper sulfate with one part zinc chloride and dilute in two parts water. A few minutes are enough for the copper to acquire a red-brown color. After washing and drying, wipe the metal surface with oil.
Patina from light brown to black
Blackening of the metal is observed when copper is patinated with ammonium sulfide.
20 g of ammonium sulfide is diluted in a liter of water. The product is dipped into the resulting solution or poured on top and wiped with a brush. The work is carried out in a fume hood. Sulfur ions present in an aqueous solution of ammonium sulfide interact with copper ions. Black copper sulfide is formed.
The intensity of the patina on the metal can be of different shades, from light brown to black. The color is adjusted by changing the heating temperature of the plate before patination.
Patina light brown
Gram per liter:
sodium dichromate - 124
nitric acid (density 1.40 gcm3) - 15.5
hydrochloric acid (1.192) - 4.65
Ammonium sulfide 18% solution - 3-5
Apply with a brush immediately after preparation, rinse off after 4-5 hours and repeat after drying 2 times, polish with a dry cloth.
Dark brown to warm black patina
Gram per liter:
ammonium persulfate - 9.35
caustic soda - 50.0
for 5-25 minutes in a bath with a solution heated to 90 -95 degrees. rinse, dry, repeat 2-3 times
Olive to brown patina
Gram per liter:
Berthollet salt - 50*70
copper nitrate - 40*50
Ammonium chloride - 80*100
for 10-15 minutes in a bath with a heated solution to 60-70 degrees.
the resulting films have mechanical strength and corrosion resistance
Patina brown-black
Gram per liter:
Ammonium molybdate - 10
ammonia 25% aqueous solution - 7
the solution should be heated to 60 - 70 degrees
Golden patina
Gram per liter:
copper sulfide - 0.6
caustic soda - 180
milk sugar - 180
A solution of alkali and lactose is prepared separately and only then poured together, boiled for 15 minutes and copper sulfide added.
place the product in a heated to 90 gr. solution for 15 minutes.
Patina golden brown with crimson tarnish and moderate shine
After cleaning copper coins, you can create an artificial patina on them by placing 50 g of copper sulfate and 5 g of potassium permanganate per 1 liter of water in a solution, heating it to a temperature of 70-80C and holding it there until the desired color is obtained.
Green patina
The surface of copper, brass or bronze products can be painted green in various ways.
Method No. 1
Using a sponge, the surface of things is first lubricated with a highly diluted solution of copper nitrate with the addition of a small amount of table salt. Then, when the item dries, it is lubricated in exactly the same way with a solution of 1 part potassium oxalate and 5 parts ammonia in 94 parts weak vinegar. Let it dry again and again lubricate with the first solution; then, after drying, again with a second solution, etc. alternately until the coloring acquires the proper strength.
Before lubricating, the sponge soaked in the solution should be squeezed out firmly so that it is damp, but not wet. After painting the surface, rub the items thoroughly with hard hair brushes, especially in the recesses and crevices. After 8-14 days of work, a brownish-greenish color is obtained.
Method No. 2
Things are rubbed in several stages with cloth soaked in crude oleic acid (a product obtained in stearin factories). On the surface of things, a dark green layer of copper oleic acid is first formed, which, under the influence of oxygen and air moisture, gradually turns into lighter green copper carbonate.
The process is significantly accelerated if oleic acid is first infused on copper shavings for quite a long time, and after each lubrication with such acid, after the lubricant has dried, the items are lightly sprayed (no more than a few drops!) with an aqueous solution of ammonium carbonate.
Yes, I did it!
Here it is, this sulfur liver, made with your own hands.
And it turned out that the devil is not as scary as he is painted.
Lately I have started making some things from copper tape. Patination of copper with ammonia vapor and a purchased silver blackening compound turned out to be unsuccessful. Helped Sulfuric ointment, but the process is painfully dirty.
A everything came together here.
I bought sulfur and potassium carbonate at a chemical store, a ceramic crucible, and a respirator at a hardware store.
I decided to carry out the process at the dacha, but since there is gas there, and experts recommend not using an open flame, the last purchase was an electric stove.
A talkative sales consultant, checking the tiles, told us that he had the same one at his dacha and what appetizing smells of borscht from vegetables from his own beds spread through the air, congratulated us on a successful purchase and wished us to cook on the tiles for a long time and tasty. My husband and I looked at each other and giggled. “If only you knew that I’m going to cook with it,” I said: “It definitely won’t smell like borscht. It will smell like sulfur.” And we left under the bewildered gaze of the seller, taking away our successful purchase.
I carried out the process in a barn, with the door open, wearing a respirator. I constantly stirred the mixture in the crucible with a screwdriver at medium heat. The composition turned yellow, then began to brown and cake into small lumps. After 10-15 minutes I removed it from the heat.
There were no horrors described by other experimenters: no hellish stench, no burning of sulfur, no sticking of the composition to the surface. But nevertheless, the excitement took its toll: I squeezed the pliers with which I was holding the crucible with such force that the edge of the ceramic crucible crumbled. Next time I will use metal utensils.
Then it was necessary to test the resulting composition.
I made a textured plate and wove a bracelet. (And this is all instead of digging up garden beds))
Here are the results.
Plate 6 cm by 5 cm
And this is a bracelet
Overall, the weekend was very successful!
Page 2
Replacing potash with soda ash when preparing sulfur liver results in darker oxide films.
This reaction is called the liver sulfur formation reaction.
For chemical oxidation, a liver sulfur solution is used. Sulfur liver is prepared by fusion for 15 - 20 minutes. Sulfur is melted in an iron vessel and then dry potash is added to it. The resulting alloy is crushed and dissolved in water.
For chemical oxidation, a liver sulfur solution is used. Sulfur liver is prepared by fusing one part by weight of sulfur with two parts of potash for 15-20 minutes. Sulfur is melted in an iron vessel and then dry potash is added to it. The resulting alloy is crushed and dissolved in water.
The precipitate resulting from the action of sulfur liver on heavy and strontian earths can in no case be considered as a simple combination of sulfur with these earths.
This reaction is called the liver sulfur formation reaction; it passes through all compounds containing sulfur.
On copper, tombac and bronze, liver of sulfur forms red oxide films with various shades; On brass the color is greenish-brown. Depending on the time the brass remains in the liver sulfur solution, as well as on the subsequent rubbing of it with pumice powder, lighter or darker brown tones are obtained.
Blackening to look like old silver is done with a solution of sulfur liver, which is prepared in a workshop by fusing one part by weight of sulfur with two parts of potash for 15 - 20 minutes. The resulting mass is dissolved in warm water in an amount of 20 - 30 g / l, the solution is heated to 60 - 70 C and immersed in it for 2 - 3 minutes.
This is accomplished by oxidizing silver in a liver of sulfur solution consisting of one part (by weight) of sulfur and two parts of potash.
Blackening of the surface to look like old silver is done with a solution of sulfur liver, which is prepared in the workshop by fusing one part by weight of sulfur with two parts of potash for 15 - 20 minutes. The resulting mass is dissolved in warm water with a concentration of 20 - 30 g / l, then the solution is heated to 335 - 345 K and the fat-free parts are immersed in it for 2 - 3 minutes or the solution is applied with a brush. The dried dark film is lightly brushed with brass brushes to brighten the metal in convex areas.
To blacken old silver, they use a solution of sulfur liver, which is prepared in a workshop by fusing 1 wt. The resulting mass is dissolved in warm water in an amount of 20 - 30 g / l, the solution is heated to § 0 - 70 C and the fat-free parts are immersed in it for 2 - 3 minutes or the solution is applied with a brush and dried, after which it is brushed with brass brushes. To protect electrical parts from oxidation, electrolytic deposition of rhodium or beryllium hydroxide is used.
Patination is the artificial aging of materials to give them an exquisite decorative and antique look. We would like to offer you a recipe for liver sulfur solution for patination of products.
You will need:
- feed sulfur
- baking soda
- heating container
- spoon
- dark glass container
Sulfur can be bought at any pet store, it costs about 30 rubles. Use an iron mug for heating and an aluminum spoon for stirring. You will also need a dark glass container for the finished solution (preferably with a large neck, so that some products can be immersed immediately). Prepare in a well-ventilated area with an exhaust hood. Remember that the rate of oxidation of the product depends on the concentration, temperature and time of exposure of the product in the solution. Some stones are sensitive to sulfur liver (malachite, turquoise, etc.), in such cases the solution must be carefully applied with a brush to a heated product. The prepared solution can be stored in the refrigerator for more than a month. Don't forget to sign!
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So, let's start preparing sulfur liver. Pour 1 part sulfur and 1 part baking soda into a cooking container. Mix thoroughly and get rid of lumps. Then heat the mixture over low heat, stirring it with a spoon ( If heated quickly, the sulfur may ignite!). Bring to a bright yellow, slightly brownish color. Add warm water and stir. Carefully pour the solution into a dark glass container.
To reuse the solution, heat it in a water bath. Place the product in the container and wait for the color you want. Then rinse under running water, wipe with a cloth and polish with a metal sponge.
OXIDATION OF THE SURFACE OF METAL ELEMENTS
AGING OF COPPER, SILVER, BRONZE OR BRASS WITH AN AQUEOUS SOLUTION
LIVER SULFUR
Sulfur liver (Liver of sulfur / Liver of sulfur) - potassium polysulfide or sodium polysulfide.
Copper and silver are well patinated with an aqueous solution of sulfur liver, gradually acquiring a thick black color, while bronze and brass have faint shades.
Sintering of the patinated composition over a fire gave it the name “liver” in the old days - from the word “furnace”, “to sinter”.
Patina- film (plaque).
Patina comes in two types: natural and artificial.
Natural patinaA- this is a thin, but quite dense and durable oxide film that forms on the surface of decorative elements under natural conditions (under the influence of the environment).
Natural patina is often considered noble and, as a rule, they try to protect it.
Artificial patina- a coating formed on the surface of decorative elements after applying various mastics, solutions and other compositions intended for this purpose to their surface.
Oxidation- creation of an oxide film on the surface of a decorative element as a result of an oxidation-reduction reaction. Oxidation is used, among other things, to obtain a beautiful decorative coating.
To oxidize copper, silver, bronze or brass you will need :
The object itself, the surface of which will be treated with a solution of sulfur liver;
Liver sulfur (working concentration - 10 g of liver sulfur per 1 liter of water, however, by changing the concentration,
solution temperature or exposure time, a wide range of patina colors can be obtained on copper and silver -
reddish brown and purple to black);
Glass or plastic container;
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