Bone can be easily sawed with a hacksaw and can be processed well with a file. It is drilled with feather drills, and openwork carving is done with burs using a flexible shaft of a burr machine.
The bone is polished on a cotton wheel using mastic, which is prepared from tooth powder, pork fat and turpentine.

Various jewelry and crafts are also made from bones. For example, you can try to make a ring from it.
To do this, you need to cut a piece 10-15 mm wide from the tubular bone. Then expand this piece of bone from the inside according to the size of the finger. Then the surface is treated with a file, giving it the required form and rounding outer parts.
The top area of ​​the ring should remain flat. You can cut out a monogram or some kind of design on it, or make cuts around the circumference with a triangular file.
Bone can be stained different colors. Before painting, it is degreased with alcohol.

Bone products can be tinted, surface painted, or deep stained. Tinting is done with graphite powder or a saturated solution of watercolor paints, in which the product is placed for 3-5 minutes. After tinting, the carved product is polished on a clean rag wheel. Tinting emphasizes the depth of the carving.
Surface coloring is done with aniline or natural dyes. Natural dyes are the most ancient material for dyeing bone.

To stain, the bone is first degreased and then dipped for some time in a strong infusion of dye. When stained with onion skins, the bone takes on a red-brown hue, while tea gives a yellow-brown color. Bone painted with tea or onion skins hardly fades.

To stain the bone, pour boiling water (3 parts) over tea or onion peel (1 part) and leave for about an hour in a sealed container. In this infusion, the bone must be boiled for 30-40 minutes.
Bone products can also be dyed with aniline dyes for wool fabrics. They provide an even, colorful coating onto which a white design can be engraved. But aniline dyes fade easily in the sun.

The deep staining process is more complex and requires careful degreasing of the bone.
The bone is boiled in an enamel bowl for 5-7 hours in a solution of soda ash (50 g per 2-3 liters of water), then washed with warm water and dried. Stain the bone in a dye solution for 7-12 days in a glass or enamel container.

To obtain a blue dye, dilute 1 part of copper sulfate in 6-9 parts of water and add ammonia until the desired color is obtained.
The bone is stained yellow with a solution of potassium dichromate in water (in the same proportion).
To obtain green dye, mix 2 parts blue and 1 part yellow dye.
The bone is stained purple with a solution of cobalt chloride.
Brown color is obtained by mixing yellow (1 part) and violet (2 parts) dyes.

A wide variety of bone products can be painted: buckles, buttons, pendants, bracelets, combs, hairpins, crochet hooks and boxes, knife handles and miniature sculptures. And even billiard balls! So, to paint the balls black, you need to hold them for several minutes in a hot decoction of blue sandalwood, and then place them in a solution of acetic acid salt.

Ivory products can also be plated with silver. To do this, they are immersed in a weak solution of silver nitrate, and as soon as the solution turns dark yellow, the products are removed and immersed in clean water and exposed to the sun. When, after a few hours, the bone is completely black, it is rubbed with a piece of leather. After this, the polished product acquires a beautiful shiny silver shade.

In contact with

There is a gateway - a fish tooth is precious
The cutouts are intricately cut.
And only in the cutout - I get goosebumps.

Folk riddle

The birth of the craft

Archaeological finds make it possible to assert that man began to process and use animal bones for household, and then for decorative purposes, back in ancient times.

Some finds on the territory modern Russia, date back to the 6th century BC. Of course, technology was not yet developed at that time and the products were far from the finest lace carving that fascinates us so much now.

In those ancient times, bone largely replaced people's lack of iron; many tools were made from it, such as needles and awls.

Gradually, iron firmly came into use, but this did not replace, but rather even strengthened and diversified the bone-carving craft. With the advent of metal tools, more opportunities appeared for processing bone, and products became more diverse.

Products

Artistically processed bone is used as a decorative finish, and entire objects are made from it. The art of bone carving is equal to jewelry.

• caskets
• Jewelry
• decorative ornaments
• constituent elements of household items

and much more.

Carved bone has many advantages. It is strong, durable, and impact resistant environment. One of the most important advantages is that the processed bone is very beautiful.

A pleasant beige shade always looks elegant and light. Products glow from the inside, this is especially evident in openwork carved products.

Table cutlery, boxes, knife handles, decorations on weapons - bone is a favorite material when it comes to expensive, highly artistic products.

About the material

“Carved bone” is a general concept. In fact, masters use different types bones, including horns, as well as elephant, mammoth and walrus tusks. The bones of cattle - tarsus - are also used.

Bones vary in color, shine, and texture. Mammoth ivory has a warm yellowish tone and a texture in the form of a miniature mesh. Walrus ivory is lighter and cooler in color, unlike mammoth ivory, and has a cellular interior, which somewhat narrows the possibility of creating artistic products.

Before carving begins, the bone is degreased, and then, using incisors, various products are cut out. There is no need to degrease the horns.

Bone carving in modern times

The bone carving industry continues to develop. This is due to the undying demand for such products. Carved bone is very beautiful and decorative, but quite expensive.

Enterprises continue to operate in the Russian North and in the Nizhny Novgorod region. Not long ago, fishing was restored in Khotkovo.

The products of past and contemporary bone carvers are kept in major museums in our country and are known abroad.

Photo gallery

In these places they have learned to use the bones of local animals or use imported raw materials.

Kholmogory bone carving craft is the oldest. The rest arose already in Soviet times.

Types of bone carving

There are a lot of carving techniques:

• sculptural
• typesetting
• openwork carving
• turning
• inlay
• burning

All this is done manually using special tools that have undergone quite strong evolutionary changes. For example, a drill with various convenient attachments is now widely used, while a century and a half ago such automation was not even thought of.

Bone has excellent decorative properties and is easy to process. Products made from it, made by folk craftsmen, have long been famous. Bone can be used to make openwork combs, carved boxes, handles for knives and forks, and other things.
In modern decorative and applied arts, several types of ornamental bone are used: mammoth tusks, tusks and teeth of a walrus, sperm whale teeth, simple animal bone: cow, horse, camel, walrus. The most widespread use in artistic crafts is now simple bone.

Bone can be easily sawed with a hacksaw and can be processed well with a file. It is drilled with feather drills, and the openwork carving is made with burs using the flexible shaft of a burr machine.
The bone is polished on a cotton wheel using mastic, which is prepared from tooth powder, pork fat and turpentine.

Various jewelry and crafts are also made from bones. For example, you can try to make a ring from it.
To do this, you need to cut a piece 10-15 mm wide from the tubular bone. Then use a round file to expand this piece of bone from the inside according to the size of the finger. Then the surface is processed with a file, giving it the desired shape and rounding the outer parts.
The top area of ​​the ring should remain flat. You can cut out a monogram or some kind of design on it, or make cuts around the circumference with a triangular file.
Bone can be painted in different colors. Before painting, it is degreased with alcohol.

Bone products can be tinted, surface painted, or deep stained. Tinting is done with graphite powder or a saturated solution of watercolor paints, in which the product is placed for 3-5 minutes. After tinting, the carved product is polished on a clean rag wheel. Tinting emphasizes the depth of the carving.
Surface coloring is done with aniline or natural dyes. Natural dyes are the most ancient material for dyeing bone.

To stain, the bone is first degreased and then dipped for some time in a strong infusion of dye. When stained with onion skins, the bone takes on a red-brown hue, while tea gives a yellow-brown color. Bone painted with tea or onion skins hardly fades.

To stain the bone, pour boiling water (3 parts) over tea or onion peel (1 part) and leave for about an hour in a sealed container. In this infusion, the bone must be boiled for 30-40 minutes.
Bone products can also be dyed with aniline dyes for wool fabrics. They provide an even, colorful coating onto which a white design can be engraved. But aniline dyes fade easily in the sun.

The deep staining process is more complex and requires careful degreasing of the bone.
The bone is boiled in an enamel bowl for 5-7 hours in a solution of soda ash (50 g per 2-3 liters of water), then washed with warm water and dried. Stain the bone in a dye solution for 7-12 days in a glass or enamel container.

To obtain a blue dye, dilute 1 part of copper sulfate in 6-9 parts of water and add ammonia until the desired color is obtained.
The bone is stained yellow with a solution of potassium dichromate in water (in the same proportion).
To obtain green dye, mix 2 parts blue and 1 part yellow dye.
The bone is stained purple with a solution of cobalt chloride.
Brown color is obtained by mixing yellow (1 part) and violet (2 parts) dyes.

A wide variety of bone products can be painted: buckles, buttons, pendants, bracelets, combs, hairpins, crochet hooks and boxes, knife handles and miniature sculptures. And even billiard balls! So, to paint the balls black, you need to hold them for several minutes in a hot decoction of blue sandalwood, and then place them in a solution of acetic acid salt.

Ivory products can also be plated with silver. To do this, they are immersed in a weak solution of silver nitrate, and as soon as the solution turns dark yellow, the products are removed and immersed in clean water and exposed to the sun. When, after a few hours, the bone is completely black, it is rubbed with a piece of leather. After this, the polished product acquires a beautiful shiny silver shade.
Bone processing
Gray antler mordant

To paint the horn gray, first boil it for 15-30 minutes in a saturated solution of lead sugar, then rinse it in clean water and put it in a solution of nitrate, mercuric oxide, heated to 60°C for 20-25 minutes. This method is not suitable for combs, since the teeth suffer from cooking.

Red mordant for horn

To dye the horn red, the following method is recommended. The light horn is boiled for 30 minutes in a solution consisting of 20 g of safflower and 10 g of soda in 0.5 liters of water, and then placed in a weak solution of tartaric acid for half an hour. Then they take it out and, after washing, put it again in a safflower solution and then again in a solution of tartaric acid, and so continue until the desired color is formed. This way it is easy to get all shades from the lightest to the darkest red. You just need to remember that the tartar bath should always be the last one.

Black mordant for horn

As is known, horn products, such as combs, buttons, cufflinks, etc., are often painted black to imitate them as more expensive varieties.

There are several ways to do this:

A) Products made from horn are soaked in the following solution, which is prepared in the cold: 8 parts of mercury are dissolved in 8 parts of concentrated nitric acid and 32 parts of soft water. The products are left in this mordant overnight, after which they are removed and washed with water until the wash water is no longer acidic. This treatment turns the combs red, and if a more concentrated solution of mercury is used, they turn brown. After this, the combs are transferred to a weak solution of liver sulfur (1 g per 1 liter of water) for 1-2 hours. The now black-colored combs are washed first clean water, then acidified with vinegar and finally with clean water. After this they are dried and polished. With the help of such processing, horn products are obtained that, according to experts, are not inferior to products made from buffalo horn. Polishing painted objects must be done carefully, as the mordant does not penetrate deep enough into the horn.

B) Horn products are placed overnight in a cold aqueous solution of lead nitrate (1:4 ratio), after which they are placed for half an hour in a 3% solution of hydrochloric acid and finally washed with water. If the coloring turns out to be uneven, the operation is repeated again. This excellent mordant significantly increases the value of horn products.

Tortoise horn mordant

If you want to give horn products a tortoiseshell color, then use the following method. Horn products are first treated with diluted nitric acid (1 part to 3 parts water) at a temperature of 30-35 ° C and then pickled with a mixture of 2 parts soda, 1 part freshly burnt lime and 1 part lead litharge. The effect of the mordant should last no more than 10-15 minutes for the spots on the horn to turn yellow-brown. After this, having washed off the mordant from the horn, wipe it with a cloth and place it in a cold dye bath consisting of 4 parts of mahogany decoction (at 10° according to Baume) and 1 part of sodium hydroxide solution (at 20 ° according to Baume). Then the horn is removed from the bath, thoroughly washed with water and polished after 12-16 hours. A dye decoction is prepared by boiling 0.5 kg of fernambuco wood in 4-6 liters of water. If you add tin salts to the mordant, you get a bright red hue.

Whitening ivory

To return yellowed ivory to its original whiteness, one of the following methods is practiced. The ivory is covered with a thin layer of turpentine and exposed to the sun for 3 or 4 days. Another way: ivory is immersed in hydrogen peroxide for a while, after which it is wiped dry. To speed up the bleaching process, the bone is exposed to the rays of a blue quartz electric lamp. With both methods, the bone becomes completely white.

Silver polished ivory

Ivory items can be given a very impressive shiny silver polish. Here is a very simple method: after finishing, the ivory product is immersed in a weak solution of silver nitrate and, as soon as it turns dark yellow, it is immersed in clean water and exposed to the sun. After about three hours the bone turns completely black; then it is carefully rubbed with rawhide, after which the bone acquires a beautiful shiny silver polish.

Coloring billiard balls

To dye billiard balls red, they should be immersed in vinegar, in which cochineal has been previously soaked, and boiled in this vinegar for several minutes. Then, to give the color a deeper shade, the balls are transferred for 10-15 seconds to a very weak solution of potash.

After keeping the billiard balls for 6-8 hours in vinegar or alum solution, they can then be easily painted an excellent yellow color, for which it is enough to dip them in an alum saffron decoction for a while. Green coloring is achieved by immersing the balls in vinegar, in which 1 part ammonia to 3 parts verdigris is dissolved. If you then transfer these balls into hot potash lye, they will turn blue. Finally, to paint billiard balls black, they should be kept for several minutes in a hot decoction of logwood (blue sandalwood), and then transferred to a solution of acetic acid.

Aniline mordants for bone

Etching bone with aniline dyes is easier than other methods, since it is carried out in a cold bath, which eliminates the possibility of cracking of objects. Etching is carried out as follows: objects are placed in a basin and so much water is poured in that they are completely covered with it. Then 2 teaspoons of vinegar and about 1 g of paint are added to the liquid, and it doesn’t matter whether the latter is soluble in alcohol or water. For the desired shades, select suitable aniline dyes or combine them from several. Bone objects are left in the liquid for 4-8 hours and removed immediately when the desired tone density is achieved. Then they are washed with water, dried and polished with Vienna lime and soap. Alcohol varnishes and polishes should not be used here, as they can dissolve the paint on the surface of the bone.

If you need to paint an ivory billiard ball in two colors in parallel stripes, then, already polished, it is clamped between three thin sticks inserted vertically into a small board, the middle strip is covered with oil varnish and first one segment is painted, immersing the ball together with the board into the appropriate aniline mordant. Having finished painting, let it dry, and clean off the varnish with turpentine and paint this part in the required color, having previously covered the finished part of the ball with oil varnish. Proceed in a similar way if the ball needs to be painted on three or four sides.

Food waste generated from meat processing includes bones and tendons. The amount of waste depends on the type of meat and its fatness. Bones are used to make broths. Before use, the cleaned bones are cut so that the food substances are better digested during heat treatment. They cut the bones with an ax on a cutting chair. Large enterprises use bone crushers or saw bones on bone saws. In tubular bones, the thickened part is sawed off at both ends, and the tube is left intact. Vertebral bones are cut into vertebrae and crosswise, large bones are cut into pieces 5-7 cm in size. After grinding, they are washed.

The costal and scapular bones are used for technical purposes.

§ 10. Semi-finished products coming from procurement enterprises

and meat processing plants

Supplying public catering establishments with semi-finished meat products produced at large procurement enterprises, kitchen factories and meat processing plants makes it possible to use equipment more efficiently, mechanize labor-intensive processes, and increase labor productivity.

Enterprises receive semi-finished products: large-piece, portioned, small-piece and chopped products. Semi-finished products must comply with the technical specifications of MRTU 18/90-65. Chopped semi-finished products are produced in accordance with OST 49 121-78. Signs of spoilage and tanning are not allowed. Natural portioned semi-finished products should have a non-weathered surface, moist but not sticky. Breaded semi-finished products must have smooth edges and a breading layer thickness of no more than 2 mm. Pieces of small-sized semi-finished products must be of the correct shape, have the smell and color characteristic of this type of meat. Semi-finished minced meat products have a uniformly breaded surface, without cracks or broken edges.

Large-piece semi-finished products are made from beef, lamb, veal and pork. They are separate parts of meat, trimmed of excess fat, films, and tendons. The following semi-finished products are produced from beef: tenderloin- muscle covered with shiny tendon;

thick edge- a layer of pulp of a rectangular shape, covered on the outside with shiny tendon; without muscles and tendons adjacent directly to the spine;

thin edge- a layer of pulp of a rectangular shape, covered on the outside with shiny tendon;

top part- round-shaped pulp from which coarse tendons have been removed; inner part- large rounded muscles covered with a thin surface film;

side part- large muscles of a square-flat shape;

outer part- a layer of meat from two fused muscles, has an elongated flat shape;

scapular part- the flesh is divided into two parts: the shoulder wedge-shaped and the shoulder - consisting of two oblong muscles connected together by a film; subscapularis- square-shaped pulp;

brisket- pulp removed from the sternum and the adjacent lower third of the rib;

hem- a rectangular layer of meat;

cutlet meat- pieces of meat of various sizes from the neck, flank and trimmings, as well as trimmings from meat carcasses of category II.

The following semi-finished products come from lamb, veal and pork: loin- dorsal and lumbar parts with rib bones no more than 8 cm long, without vertebrae;

hip part- the flesh of the hind leg without stringy meat;

spatula- pulp removed in one layer from the scapula and humerus bones, without meat adjacent to the ulna and radius bones;

brisket- rib part of the pulp with rib bones, without breast bone and flank;

neck- pulp, removed in one layer from the neck of pork;

cutlet meat- pieces of meat of various sizes from the neck part (except pork) and trimmings obtained by stripping large-sized semi-finished products.

Large-piece semi-finished products are delivered packed in metal or wooden boxes weighing 20 kg. The lids of the boxes have holes for air access. Large-piece semi-finished products from one type of meat, manufactured at the same time, should be placed in boxes. They are stored at a temperature no higher than 6 °C for no more than 48 hours. from the moment of manufacture. Tenderloin can be supplied frozen in blocks weighing no more than 20 kg. At the enterprise, large-piece semi-finished products are removed from the container, washed and used to prepare portioned semi-finished products.

Portioned semi-finished products. From beef The following semi-finished products are supplied: steak, fillet, languette, entrecote, brass beef, natural zrazy, cut into pieces weighing 80 or 125 g, rump steak without breading, weighing 70 or 110 g and breaded rump steak, weighing 80 or 125 g.

From lamb and pork semi-finished products are supplied: natural cutlets, escalope, oven-baked lamb or pork, weighing 80 or 125 g; chops and schnitzel without breading, weighing 70 or 110 g; breaded chops and schnitzel, weighing 80 or 125g.

Portioned natural and breaded semi-finished products are supplied in metal or wooden boxes. They are laid on board or metal liners in one row obliquely, so that one semi-finished product is partially under the other. There should be no more than three inserts in the box. Portioned semi-finished products are stored at a temperature of 6 °C, the shelf life from the moment of production of natural semi-finished products is 36 hours, breaded - 24 hours.

Small-piece semi-finished products come in the following assortment: beef stroganoff, azu, frying, goulash, stew, pilaf, lamb, pork, beef kebab. Small-piece semi-finished products arrive at enterprises packaged in the same way as large-piece semi-finished products. For retail sales, they are packaged in cellophane or parchment bags of 125, 350, 500 and 1000 g, after which they are placed on liners.

Of the minced products, the enterprises supply cutlets (weighing 50 g), meatballs and steaks.

Moscow cutlets prepared from beef with the addition of raw lard.

Homemade cutlets prepared from beef and pork with the addition of onions.

Kyiv cutlets prepared from beef with the addition of bacon. The shape of the chopped steak and cutlets is round.

Semi-finished products arrive laid in one row on liners, sprinkled with breading; steaks are laid without breading.

Semi-finished chilled chopped meat products come in the following assortment: natural chopped schnitzel, chopped schnitzel, natural chopped cutlets, lula kebab. They are dosed and molded on AK-2M-40, K6-FAK-50175 machines. The semi-finished product “natural chopped schnitzel” is molded weighing 96 g, “chopped schnitzel” - 61, “natural chopped cutlets” - 71, “lula-kebab” - 71 g. Then they are placed in one row in functional containers, greased, covered with lids, installed in containers and subjected to intensive cooling to a temperature of 6-8 °C inside the product. Store in refrigerators at temperatures from 4 to 8 °C for no more than 14 hours.

The most popular, and for some areas the only, material for making various works of art, jewelry and household items is bone - walrus tusks, elephant and mammoth tusks, sperm whale and narwhal teeth, tarsus (domestic animal bone). In addition, for the manufacture various crafts bones of large marine and domestic animals, antlers of deer, antelope, and rhinoceros horn are used. Turtle shells are close to these materials.

Bone (tusks, fangs, tarsus) is a complex organo-mineral formation. The inorganic part (55-70%) consists mainly of calcium salts (phosphates, carbonates, fluorides); organic (45-30%) - ossein. These substances form a complex structure, penetrated by capillaries and pores, which has anisotropy (the reason for warping of the plates).

10.1.1. PRODUCTS FOR CLEANING BONE PRODUCTS FROM SURFACE CONTAMINATION

Products made from bone are in good and satisfactory preservation (i.e. when the material is not destroyed, the bone has retained its chemical composition, no visible fungal damage, grease stains or metal oxides) and poorly preserved bone objects require different approaches to cleaning, conservation and restoration.

The first group of products usually requires only cleaning and strengthening (installation, gluing), their further restoration depends on the subsequent purpose of the product - display, preservation in the fund, use for further study. Bone exhibits that have fractures, areas of destruction of the material, dirt and stains of various origins require thorough cleaning and subsequent strengthening, removal of stains, general cleaning, replenishment of losses, tinting, etc.

The ethical and aesthetic limits of a restorer’s intervention in the appearance and material basis of a bone exhibit are determined not only by established views on the appearance of the object and fears for its future fate, but also by objective indicators: for example, the presence of spots of fungal lesions can lead to their development when the humidity conditions of storage change. . Fatty, waxy, resinous contaminants can diffuse into the depths and along the perimeter when the temperature rises. Oxide-salt pollution (copper, iron) is especially dangerous. In humid air saturated with sulfur and nitrogen oxides, salts that are easily soluble in water are formed, which can interact with the inorganic component of bone - calcium, removing it from bone tissue.

Bone is painted in light colors and is a fairly porous material, so surface stains on it are clearly visible and are held quite firmly. On art products made from bone, there are ink stains, drops and streaks of paints and food products, glue, waxes, fly marks, etc. These stains undergo over time complex processes aging, cement dust particles and fix them on the surface and in the pores of the bone.

All types of contaminants actively interact with the bone material, gradually destroying it. Dust consists of fine particles of various mineral compounds (calcareous, silicate, clay, ash, coal, soot) and organic substances (resinous substances, cellulose). Having a developed surface, dust adsorbs water, sulfur and nitrogen oxides from the air. Therefore, the presence of dust on the surface leads to a change in the physical and chemical state of the bone.

Bone objects that have been in long-term use, in addition to dust, can be contaminated with adhesives, plasticine, fats, sweat and other organic substances. The components of sweat and its decomposition products contain urea, phosphates, sulfates, lactic acid, and upon decomposition they form ammonia. These substances can interact with both the mineral and organic parts of the bone, leading to the destruction of the structure of the bone material.

Fats and lubricants hydrolyze under the influence of water vapor and atmospheric oxygen. The resulting free fatty acids are oxidized, and upon their further interaction with bone material, colored products appear. Fats and lubricants easily penetrate the bone to a considerable depth. Their decomposition in depth leads to the appearance of spots of more transparent bone and indelible, intensely colored yellow spots.

Biodestroyers occupy a special place among pollutants. Along with dust contaminants, spores of bacteria and fungi get onto the bone. Some bacteria cause decay of the protein component of the bone; the waste products of mold fungi are coloring substances and organic acids. The presence of contaminants that absorb water from the air contributes to the development of biodestroyers.

The destruction of the material of bone exhibits and their premature death can only be prevented by careful removal of contaminants both from the surface and, if necessary, from the depths of the bone.

The surface of the bone is oxidized under the influence of oxygen in the air and light. The products of this oxidation have a faint yellowish-brown color, which is usually described as the “patina of time.” When cleaning from contamination, it is necessary to preserve this evidence of the effects of time on the surface of the bone. Removing patina from products is unacceptable. Therefore, the question of the degree to which bone products are cleaned from surface contamination should be decided jointly by the restorer and the art critic.

First, bone products are cleaned “dry” - with a bristle brush. If there are no specific contaminants, and dust particles are not fixed in the pore system of the bone, then a significant part of the contaminants is removed.

At the next stage, water, alcohol, aqueous and alcohol-water solutions of various detergents are used to remove contaminants." It should be taken into account that the anisotropy of bone requires careful use of aqueous solutions to clean it. Warping of bone when absorbing water cannot always be corrected. As a detergent products usually use household preparations “Progress”, “Novost”, “Astra”, “Lotos”, “Era”, OP-7, OP-10, which have a neutral or slightly alkaline reaction.

In restoration practice, when cleaning bone products from surface contaminants, nonionic detergents are widely used - polyoxyethylene ethers of fatty alcohols (syntanol DS-10, tergitol, Volpo, etc.), polyoxyethylene ethers of alkylphenols (OP-7, OP-10); oxides of organic amines (alkyldimethylamine oxide), highly soluble both in water and in a number of organic solvents (alcohols, ethers, ketones); cationic detergents are high-molecular organic amines (katamine AB), which exhibit biological activity and therefore also perform the function of antiseptics. These detergents are used in the form of 0.5-2.0% aqueous or aqueous-alcohol solutions. Sintanol DS-10, alkyldimethylamine oxide and some other individual detergents can be used to wash bones in the form of solutions in ethers (ethyl acetate, diethyl ether) and alcohols (ethyl alcohol, isopropyl alcohol). Anhydrous detergents are preferable when working with partially destroyed bone.

Heavily contaminated surfaces (presence of fatty, protein contaminants) are cleaned with formulations containing enzyme additives. Below is one of these compositions, operating at 20-40 ° C, %:

Sintanop DS-10 - 2.0

Lipase enzyme - 0.5

Protease enzyme - 1.0

Distilled water - 96.5

In some cases, grease stains, drops and traces of oil paint can be removed from bones using organic solvents - gasoline, ethyl alcohol, ethers, perchlorethylene. Cleaning is carried out by immersing the product in a solvent, brushing, applying a swab moistened with a solvent, or a chalk paste with a solvent. To clean bone, you should not use compositions that contain surface-modifying substances, for example, VEPOS composition,%:

Oleic acid - 2.6

Hydrophobizing liquid GKZh-94 - 1.6

Gasoline - 48.4

Emulsifier OP-7 (or detergent"Progress") - 0.5-2.0

Water - Up to 100

The hydrophobizing liquid GKZh-94 and oleic acid are sorbed on the surface of the bone and prevent its further processing with aqueous compounds, making tinting and gluing difficult.

Good results are obtained by polymer film-forming compositions, which can be used to treat both the entire surface of an exhibit and its individual sections, due to the fact that the cleaning composition can have a sufficiently high viscosity and does not spread over the surface. Both water-soluble polymers - PVA, Na-CMC, and alcohol-soluble polymers - polyamides, PVB, as well as polymer dispersions (latexes) - PVAD, synthetic rubber dispersions, etc. can be used as film-forming agents. To reduce adhesion, polybasic alcohols - glycerin, polyethylene glycol (low molecular weight) - are introduced into film-forming compositions. Below are the compositions of some compositions, parts (wt.):

PVS - 15-20

Glycerin - 3-5

Sintanol DS-10 (DS-20, OP-7, OP-10, alkyldimethylamine oxide) - 0.2-0.5

Glycerin - 3-5

Sintanol DS-10 (DS-20, OP-7, OP-10, alkyldimethylamine oxide) - 0.2-0.5 Water - 5-7

Alcohol-soluble polyamide - 10

Glycerin - 1

Sintanol DS-10 (DS-20) - 0.05-0.1

Ethyl alcohol* (isopropyl alcohol) - 100-150

* In some cases, polyamides are dissolved in 75-80% alcohol solutions.

Film-forming solutions may contain enzyme additives (lipase, protease), which increase the efficiency of cleaning the bone surface from specific contaminants.

Sufficiently old bone products, cleaned of surface contamination, have a faint yellowish-brown color, which may be a consequence of natural aging (the patina of time) or specially performed tinting. As a rule, such coloring is not removed, and individual areas of the light surface (places where specific contaminants are removed) are tinted with natural or synthetic dyes.

10.1.2. BONE WHITENING PRODUCTS

Whitening compositions are selected depending on the nature of the substances that form stains on the surface of the bone.

We often have to deal with ink stains. Various inks and liquid coloring compounds penetrate deeply into the porous structure of the bone and treatment with detergents only weakens the intensity of the stain on the surface. To remove ink stains, use rectified ethyl alcohol (96%), a mixture of ethyl alcohol with a 5% solution of acetic acid (1:1), and a 5% aqueous solution of ammonia.

Oxidizing agents are quite widely used to remove colored stains on bones - hydrogen peroxide of 3-5 and 10% concentrations, chloramine B, bleach. Solutions of these drugs (or a paste with water) are applied to the stained area of ​​the bone for several hours, then removed with a swab, washed with water, dried with alcohol and wiped dry. Chloramine B and bleach should be used with extreme caution, since the chlorine ion released in the process interacts with bone calcium, converting it into highly soluble calcium chloride.

To remove many colored spots, moistened barium peroxide BaO 2 is used, which, like hydrogen peroxide, is an oxidizing agent, but unlike hydrogen peroxide it creates a slightly alkaline environment on the surface of the bone.

Sodium perborate, sodium percarbonate, and sodium perphosphate are used as bleaching agents. Sodium perborate is a vigorous bleaching agent containing 10.4% active oxygen. The same amount of active oxygen contains sodium percarbonate (produced under the trade name “Persol”). It must be taken into account that sodium percarbonate forms alkaline solutions. Sodium perphosphate is a very mild oxidizing agent and makes it easy to control the degree of bone bleaching.

Specific contaminants on bone include calcium carbonate (archaeological objects), oxides and salts of iron and copper. Salts of other metals (for example, silver) are quite rare, and their removal should be carried out using methods for purifying the corresponding metals, taking into account the characteristics of bone as an organo-mineral formation.

To remove calcium carbonate, small areas of carbonate deposits are treated with a 1-2% solution of hydrochloric acid, followed by rinsing with water and alcohol. This treatment must be carried out quickly, since hydrochloric acid reacts quite vigorously with the mineral component of the bone. It is safer to treat with 2-5% acetic or formic acid or their mixtures, which are much less likely to destroy bone than hydrochloric acid.

Weak traces of rust are removed with a 2% aqueous solution of oxalic acid, mixtures of acetic and formic acids (2-5% solutions), tartaric and citric acids. Consistent film-forming compositions PVAD are an effective means of removing rust. alcohol solutions of PVB and polyamides with the addition of reagents for dissolving iron oxides and hydroxides, allowing only the contaminated area of ​​the bone to be treated. For this purpose, to obtain such compositions, 1-5% PMAA is added to the compositions for cleaning bone from general contaminants, citric acid or Trilon B. The compositions are somewhat weaker than the corresponding aqueous solutions, since their action is limited by the time of evaporation of water and formation of a film. After drying and hardening, the film is removed along with the dirt.

Copper contamination occurs from copper (brass) nails, hinges, and decorative foil. Copper oxides can be removed with a 5% aqueous solution of ammonia, aqueous solutions of Trilon B, and glycerin. You can treat with a 10-15% solution of sodium hexametaphosphate, which is a mild solvent for corrosion products of copper, brass, and bronze. A special place is occupied by a specific method for removing copper corrosion products - treating the contaminated surface with an aqueous suspension of ammonium cation exchanger (Dauex-5X8, KU-2X8, etc.). viscous compositions based on PVA, glycerin (3-5%) and ethylenediamine (3-5%).

10.1.3. DRYING AGENTS IN BONE RESTORATION

It is advisable to process bone in anhydrous solutions. Aqueous solutions cause warping of bone products, cracking and splitting when dried. Therefore, water treatment of the bone should be minimal, and residual water from the bone should be removed using solvents. To do this, the bone is completely immersed in a vessel filled with 96% ethyl alcohol, and after 15-40 minutes (exposure time depends on the configuration and thickness of the product), the solution is replaced with pure anhydrous alcohol. Usually, 3-4 changes of alcohol are carried out, after which the product is dried with filter paper and then dried in the open air (possibly under a light load) until the alcohol has completely evaporated. To speed up drying, you can replace the alcohol in the bone with a more volatile solvent - diethyl ether or acetone.

During all operations with organic solvents, the engraving on the bone must be preserved. Typically, engraving is overwritten with colored paints, most often wax-based. Therefore, before treating products with colored engraving with solvents, you must make sure that alcohol, ether, and acetone will not harm the colorful ornament.

If there are varnish coatings on the bone, general treatment with organic solvents should be avoided.

10.1.4. BONE ADHESIVES

The choice of adhesives when restoring bone products is determined by the safety of the material itself, the need for finishing touches and installation of complex planar ornaments or three-dimensional sculptures.

Although epoxy resins They produce a strong adhesive seam, but the plasticizer (dibutyl phthalate) that is sometimes included in the glue diffuses out of the seam over time, forming zones of bone that have changed in color and transparency in the adjacent areas. In addition, the insolubility of epoxy adhesives after curing eliminates the possibility of repeated restoration.

On the day of museum exhibits made of bone, along with traditional glues - fish, sturgeon, carpentry - aqueous glues based on PVA and PVAD, alcohol solutions of PVB, solutions of acrylic polymers (BMK-5, PBMA) in ethyl acetate, acetone, methyl ethyl ketone are used.

Restored bone products often have various losses. Replenishing repeating parts is not difficult, since you can remove the mold from an element similar to the lost one and prepare a cast. Additions and replenishment of losses on three-dimensional sculptures made of bone can only be carried out with a sufficiently high professional level restoration artist.

The best polymer base for ornamental masses are polyesters of methacrylic acid. Epoxy, carbinopic, polyester resins, polystyrene, PVAD are recognized as unsuitable for this purpose.

Good results can be obtained by using the commercially produced material noracryl-65, which contains PMMA powder mixed in a monomer (methyl methacrylate or methyl methacrylate with methacrylic acid with the addition of a stabilizer). By changing the amount of monomer added to the powder, you can vary the curing time from 5-7 to 40-50 minutes.

When replenishing the loss of a complex repeating relief, the mold is removed from the preserved area using silicone rubbers - Vixint, Sielast, etc., which form an almost non-shrinking shape, do not stick to the bone (have zero adhesion) and with high accuracy reproduce the relief. When reproducing a part in finishing mass, and for artistic carving Bone is characterized by a thin relief and often engraving on the surface; it is necessary to successively apply to the mold first a thin layer of liquid mass to fill the relief, and then subsequent layers. Finishing masses based on noracryl or carboplast are composed of zinc white (5-10%), bone meal (6-15%) and polymer (75-80%).

Bone, especially archaeological bone, can have different shades, so finishing masses are tinted by adding 1-2% microtalc. Finished parts are painted with a solution of potassium permanganate or colored varnishes.

Highly effective finishing compounds are polymer compositions based on acrylates BMK-5, 40BM, 80BM in combination with organosilicon oligomers (K-9, K-42, K-47, K-101) and bone meal. To obtain finishing mixtures, use 10% solutions of acrylic copolymers with 10-15% solutions of organosilicon oligomers, to which 1/5 of the volume is added immediately before use 10 %- solution of polymethylsilazane MCH-7. Bone meal and, if necessary, pigments are added to the finished mixture. The resulting mass is filled into the mold and left in it until completely cured (6-8 hours). The strength characteristics of the resulting casting allow it to be subjected to mechanical processing.

10.1.5. TINTING AND PROTECTIVE VARNISHES FOR BONES

Replaced fragments from new bone, places of removal of contaminants and bleaching differ in color from the main body of bone, therefore new pieces and places of clearing must be tinted.

The tones of old, darkened bone are well reproduced when new or bleached bone is treated with vegetable dyes. Before staining, the prepared bone is etched in a 1% solution of a metal salt (potassium alum, ferrous sulfate, potassium dichromate, etc.). After etching, the area of ​​bone to be painted is treated with an aqueous or alcoholic infusion of the dye.

The use of various mordants allows you to obtain a wide range of shades of the same color. Thus, when processing bones, light shades of brown are produced by aqueous infusions of oak bark, buckthorn, alder cones, and wild rosemary; yellow color - St. John's wort, saffron, barberry root; red color - madder or galangal roots, raspberry shoots; light green shades - horsetail, tansy, St. John's wort (etched with copper sulfate).

Plant dyes create a color (“tone”) on the bone that is close to the color of the old bone, but etching and processing in dye infusions should be carried out at temperatures of 60–80°C, which is impossible with fragmentary tinting.

Synthetic dyes produce harsher tones, so the restorer must use samples to select the required concentration of dye or mixture of dyes. Since bone has a protein base, direct and acid dyes, used for dyeing wool, fur, and leather, are used to dye it.

The following direct dyes are recommended for staining bone: helion green, direct bright green, direct light-fast brown 2KX, direct black 3, light-fast direct pink C, light-fast direct blue. Direct dyes belong to the class of azo dyes and are sodium salts of sulfonic acids or carboxylic acids. Bone (wool, gelatin) is dyed from neutral or slightly alkaline baths in the presence of electrolytes (sodium chloride or sulfate).

The color range of direct dyes is very wide and covers all colors from yellow to black. The simplicity of the formulation and the safety of coloring compositions for bone material make direct dyes the most convenient for the restoration and recreation of bone products. To stain bone with direct dyes, use a solution of the following composition, g:

Direct dye - 0.05-0.2

Sodium chloride (table salt) - 2.5

Water - Up to 100 ml

The introduction of an electrolyte into the coloring composition helps to obtain more intense, even and deep staining of the bone. Coloring is carried out in glass or porcelain dishes at 60-80 ° C. The duration of the process can be varied from 5 to 30 minutes depending on the desired depth of color. After dyeing, the product is washed with water, dehydrated with alcohol and dried under a press.

The following acid dyes are used for dyeing bone: acid green 4G, acid blue K, acid black C, acid burgundy, acid brown K. The recipe and dyeing technology in this case are the same as when using direct dyes, but instead of sodium chloride in the solution acetic acid is introduced. The following solution is recommended:

Acid dye - 0.05-0.2 g

Acetic acid, 30 %- i - 1 ml

Water - Up to 100 ml

Colored foil, mica, fabric or paper are usually placed under the openwork, slotted bone plates in products. These linings in the gaps of the bone plates deteriorate, fade and almost always need to be replaced or duplicated.

Metal foil (usually small) loses its varnish (colored gelatin), tinning or silvering. After cleaning the foil from dirt and remnants of destroyed varnish and leveling it, a new layer of colored varnish coating is applied to it. Commonly found foils are colored in various shades of golden yellow, green, blue and red. To obtain varnish, a concentrated solution of direct or acid dye is added dropwise to a 20% warm aqueous solution of gelatin (until the desired color is achieved in a thin layer). The warm solution is applied with a brush to the foil and tanned by surface treatment with a 10% aqueous solution of tannin or in formaldehyde vapor for several hours. Treatment of the gelatin layer with formaldehyde vapor leads to significant fragility of the film.

Colored varnishes for foil can be obtained on the basis of copal varnish, to which a pre-prepared alcohol solution of the dye is added.

If it is necessary to preserve a peeling varnish film, restorers face significant difficulties; the high degree of hardening changes the surface properties of the gelatin film; it is poorly wetted by aqueous and alcohol solutions, which makes it difficult to select adhesives. In some cases, it is possible to recreate the varnish surface by irrigating and laying gelatin film flakes with alcohol solutions of PVB or polyamide.