Sculptural clay Automatic translate
Plasticine, or rather a composition similar to plasticine, was first mentioned in the XVI century. with George Vasari in the Biographies of the Most Famous Painters, Sculptors and Architects. In terms of breadth of use in sculpture, clay takes the second place after clay. Its plastic properties are somewhat different from clay, which gives the sculptor additional opportunities for self-expression. Physical properties, its hardness, density, color, set plasticine once - during manufacture. Only during work does it become a little softer from the heat of the hands of the sculptor. Due to the fact that clay is a tougher material than clay, it is used to make small easel sculptures: miniatures, medals, genre compositions, large-scale sketches of large sculptures, working models of sculptural and architectural compositions, moldings for making small gypsum parts for ceiling painting . Plasticine differs from clay in that it does not dry, while maintaining plasticity and density. Therefore, it finds application where thin and clear modeling of the form is required. Some sculptors also use plasticine in large works, mainly for sculpting thin parts that quickly dry in clay. But for this, plasticine is subjected to additional processing. It is digested, i.e. it melts to a liquid state, a plasticizer and color pigment are added to it so that the plasticine gets into the color and medium softness of the clay from which the whole sculpture is made.
Plasticine consists of beeswax, various fillers and plasticizers. Instead of beeswax, mountain wax is often used - ozokerite. Powders of dry clay, sulfur, talc are used as fillers. In the XIX century. plasticine was made from wax and rosin (per 1 kg of wax, 0.5 kg of rosin), melted in olive oil. Its softness depended on the amount of oil. The necessary pigments were added for color. Other recipes from more affordable ingredients were later developed. For example, wax - clay, wax - sulfur, ozokerite - kaolin.
The method of preparation of all plasticines is basically the same. Finely ground clay or sulfur and powder pigment are added to the molten wax or ozokerite and all are thoroughly mixed. The resulting mass is poured in a thin layer onto a wet burlap or a thick plastic film and cool. The cooled mass is passed through a meat grinder in order to grind the lumps of unpolluted clay and pigment settled in the melt. The next step is to give the necessary plastic properties. The resulting composition is melted, machine oil or technical petroleum jelly is added for softness, and potato flour or talc for hardness. The thoroughly mixed mixture is poured (see above), cooled and tasted for softness, density, pliability.
In all cases, the ratio of components in the preparation of plasticine depends on the specific requirements of the sculptor for its plastic properties.
In addition to the described compositions of plasticine, which are prepared by the sculptors themselves, this material until recently was produced by the Podolsk Combine of the Art Fund and the plant of art paints in St. Petersburg.
To date, the most suitable sculptural sculptures are plasticines produced by Gamma OJSC and Lenstroykeramika AOZT.
Many novice sculptors, in order to facilitate the work with plasticine, first heat it up in hot water or put it on hot heaters. And during the whole session they keep a stock of hot, very soft plasticine. Of course, working with hot clay is much easier. By its plastic properties, it approaches clay and allows you to sculpt in large masses. But such prolonged heating negatively affects the plasticizers that make up its composition. With repeated prolonged heating, the components that are responsible for softness gradually disappear. Each time, the clay becomes harder and tougher, and then brittle, unsuitable for work. To restore its plastic properties, it is necessary to melt it and add plasticizers. Plasticine, like clay, is an amorphous material, and in order for the sculpture to retain its shape, you need a frame, in the manufacture of which the features of the chemical composition of plasticine should be taken into account. Fatty acids contained in its components destroy copper and copper-based alloys. Therefore, it is not recommended to use copper or brass wire. For this purpose, aluminum or annealed iron wire is recommended.
At the request of the Gamma Publishing House, the editors of the Art Council and Deco magazines, 2nd year students of the sculpture faculty of Moscow State Art Institute named after V.I. Surikov (workshop of Professor A.I. Rukavishnikov), training master - formator of the sculpture faculty M.V. Medvedev and me, the author of these lines, conducted comparative tests of sculptural clay of domestic manufacturers - companies. The following samples were taken as test samples:
1) Plasticine sculptural AOZT Lenstroykeramika;
2) Sculpted plasticine olive Gamma OJSC;
3) This sculptural clay of ZAO NPP POLIONP.
According to the testing regulations, each of the 10 students who agreed to participate in the tests was given an equal amount of clay of the listed varieties and the task was set to sculpt course assignments (sketching compositions, studies, medals) for a month. Students had to determine which plasticine, in terms of its plastic and physical qualities, is better suited for various types of sculptural works and molding techniques.
Testing results (sketches, sketches, compositions, plaques, medals) were shown at the examination examination and received positive marks from the faculty of the sculpture faculty. In addition, each student who took part in the tests had an individual conversation in order to identify the pros and cons of each material. Students had to evaluate each type of plasticine in the following positions: plasticity - the ability to sculpt as large volumes as possible; hardness - working, warm state when kneading with hands; stickiness - the ability of pieces with different temperatures to stick together; stickiness (to hands and tools); color, photogenicity; smell; safety of form; grease - the heatability of plasticizers on the surface during long-term storage; what types of sculptural work is suitable. M.V. Medvedev conducted a series of technical tests on the reaction of plasticines to various chemical compounds used in the molding of sculptures. This is a reaction to various varnishes and lubricants, organosilicon compounds, a sharp temperature difference (freezing and thawing) when molding sculptures using the adhesive form.
The following results are obtained.
“Plasticine sculptured” manufactured by AOZT Lenstroykeramika
Packaging - a rectangular briquette weighing 1 kg. The color is gray. According to 8 out of 10 respondents, this plasticine is of medium plasticity, closer to soft. With additional heating allows you to sculpt in large masses. Possible "scenic" modeling strokes, almost like clay. In working condition, it wrinkles well with hands, although sometimes (in three cases out of 10) initial heating was required, especially when printing a new briquette. It mainly adheres well to cold plasticine, only a twice-superimposed piece was detached from the sculpture when it was pulled off by a stack - a loop when leveling the surface. He practically didn’t stick to his hands and tools (9 cases out of 10), this only happened during artificial overheating. At the beginning of work with a cold metal stack - a loop on cold plasticine — whitish traces remained: the plasticine lifted up, but as soon as the stack was warmed up by the heat of the hand, the texture completely corresponded to the plan. Plasticine of pleasant even gray color. When mixing pieces from different briquettes and even briquettes from different batches, color differences were not found. The sculpture turns out to be even in color with chiaroscuro of equal strength. This is very important when photographing sketches and projects of future sculptural works, when photographs of sketches are presented to non-professionals for trial.
When opening a new briquette, a slight smell of rosin appears, but in the process of work it practically disappeared or got used to it. In any case, none of the students complained about this plasticine.
Plasticine kept its shape well at room temperature (18 - 22 ° С). In conditions of a prolonged increase in temperature to 30 ° C (when students left their sketches on a shelf in the workshop for the whole summer), a thin glossy film of plasticizers appeared on the surface. Sculptures made without a frame settled and swam. This did not interfere with letting the salted plasticine into further work. It needs to be heated and mixed well.
Particular attention should be paid to the preparation of sculptures from this plasticine for molding. The surface holds well the application of alcoholic shellac in several layers. In this case, hardening, cementation of the plasticine surface occurs. At the same time, nitro-lacquers slightly dissolve its surface. This also applies to lubricants. It is better to use soap - oil grease, as kerosene stearin dissolves the surface. Such precautions are necessary in the manufacture of the adhesive form. Additional fixation of the surface of the sculpture is also required, since gelatin glue is poured into the casing at a temperature of about 50 ° C. The sculpture before pouring glue is frozen in the refrigerator or in the winter on the street. After such a thermal shock, clay becomes brittle. This must be taken into account when removing the cooled adhesive layer from the model. It is not recommended to remove the adhesive form from this plasticine. Plasticine is absolutely neutral to organosilicon compounds. Vixintes and molding compounds can be used without lubrication on pure plasticine. Also, without varnish and grease, you can remove the gypsum piece form. This plasticine is suitable for all types of sculptural works, except for medal and miniature jewelry, where filigree accuracy and clarity of lines and shapes are needed. For such work, it is not hard enough.
According to the results of the tests, this clay was rated for a solid "four".
"Sculpted Olive Plasticine" manufactured by Gamma OJSC
Packaging - a rectangular briquette weighing 1 kg. Olive color in different shades.
According to 9 out of 10 respondents, plasticine of medium plasticity is closer to hard. But the hardness of all briquettes is different. With additional heating allows you to sculpt in large masses. In the hot form, "picturesque" modeling is possible with brush strokes, almost like clay. In working condition, it wrinkles its hands, although in b cases out of 10, initial heating was required, especially when printing a new briquette. Cold plasticine is hardly cut with a knife. It is glued to cold plasticine, but the newly applied layer must be smeared into the previous one. After such preparation, pull-off practically did not occur, with the exception of two cases. Plasticine stuck to hands and tools only with artificial overheating, when it was necessary to quickly lay large masses of material.
When working with stacks of burrs and whitish traces did not arise. The vast majority of students did not like the color (9 out of 10), especially since each briquette has its own shade. Before work, it is necessary to select briquettes by color or to melt multi-colored ones to get a single color of the entire plasticine, otherwise the sculpture becomes spotty-striped, and when it is photographed, a marriage is obtained. The wish to the manufacturer is to bring the color closer to the color of sculpted clay. During operation, clay exuded a mixture of turpentine and engine oil odors. In one student, this aroma caused an allergic reaction.
Plasticine perfectly retains its shape both at room temperature and in the summer heat (30 - 35 ° C). The appearance of plasticizers was not observed, and no molds and precipitation.
During molding operations, alcohol and nitro-varnishes can be used, and all of the lubricants, except kerosene stearin. Before removing the adhesive form, the sculpture from this plasticine is recommended to be cooled. Plasticine is absolutely neutral to organosilicon compounds. Silicone-based vixintes and molding compounds can be used without lubrication on pure plasticine. Also, without varnish and grease, you can remove the gypsum piece form. This plasticine is universal, but each type of work needs its own approach to this material. With a “juicy” pictorial molding, it must be heated in hot water, and when sculpting a miniature, in order to achieve fine detail and elaboration of the form, cool it. If it weren’t for individual flaws, such as the difference in color and hardness of briquettes in one box, this plasticine could be rated “excellent” (5 out of 10 respondents), but only “good”.
"Real sculptural plasticine" produced by ZAO NPP POLIONP
Convenient packaging: plasticine is cut into 200 g plates and laid in blocks of 2 and 4 plates, blocks of 400 and 800 g, black. Plasticine is soft. Easy to wrinkle hands. Therefore, they can work like clay. He did not require preheating in 7 cases out of 10). Separate pieces are well stuck together in a monolith. The separation of pieces was not observed. Plasticine is suitable for hand sculpting. The plasticine mass is dark gray. Differences in shades in different briquettes were not found. The dark color causes some inconvenience: the play of chiaroscuro on the sculpture is not visible. In bright light, glare appears, breaking the shape and making photography difficult.
The smell did not cause complaints, 8 students noted: “It smells, but unobtrusively.”
Plasticine holds its shape well.
When removing molds from this plasticine, it is advisable to use alcoholic shellac and soapy oil grease. It is not recommended to do a glue form because of the temperature of the glue that is too high for this plasticine. With silicones and polymer molding compounds does not react. For pure plasticine, you can also remove the plaster mold. According to the general opinion of the testers, this plasticine is intended for molding in a juicy, picturesque manner, where the movement of the smear in shape is of primary importance. Plasticine deserves a solid rating of "good."
None of the tested materials received the highest rating, not because the testers were very picky or tough, but because each plasticine has its own shortcomings. While working with these materials, the sculptor has to think not about what he wants to express, but about how to adapt to the material, what needs to be done with him so that he becomes obedient. Ideally, the sculptor should take clay and work, create, and the material - meekly obey the hand or tool. One gets the impression that not one of the manufacturers was interested in consumers which plasticine and with what properties they needed. For almost 10 years I have been the head of the laboratory of engineering and technology for sculptural materials, and this is the first appeal to us with a request for testing materials. I hope that the critical comments and unflattering reviews expressed in this article will help manufacturers to improve the quality of the materials they produce.