Do-it-yourself ceramics: how to become a ceramist and what you need for this

CERAMICS
(Greek keramike - pottery art, from keramos - clay; English ceramics, French ceramique, German keramik), the name of any household or artistic products made of clay or mixtures containing clay, fired in an oven or dried in the sun. Ceramics include pottery, terracotta, majolica, faience, stone mass, porcelain. Any object formed from natural clay and fixed by sun drying or firing is considered pottery. Porcelain is a special type of pottery. Translucent, with a glassy sintered shard and a white base, real porcelain is made from special varieties of clay, feldspars and quartz or quartz substitutes.
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Making pottery is an ancient art, predating metallurgy or even weaving in most cultures. Porcelain, however, is a much later invention; it first appeared in China ca. 600 AD, and in Europe - in the 18th century.

Material.

The main material for the production of ceramics is clay. Extracted clay is usually mixed with sand, small stones, rotted plant debris and other foreign substances, which must be completely removed to make the clay usable. Today, as in ancient times, this is done by mixing clay with water and letting the mixture sit in a large bath. The mud settles to the bottom, and the top layer of clay and water is pumped out or scooped into an adjacent reservoir. The process is then repeated, sometimes several times; the clay is purified with each subsequent sediment until the material of the required quality is obtained.

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DECORATIVE ARTS

Purified clay is stored in a damp state indoors until it is used. Aging clay for several months significantly improves its working qualities, allowing the clay to maintain its shape during the creation process, remaining pliable and plastic. Fresh clay is often combined with old clay from a previous mixed batch; this increases bacterial activity and appears to improve the quality of the material.

Any product molded in clay undergoes some degree of compression, both during drying and during the firing process. To ensure even drying and minimal shrinkage, roughly ground pieces of terracotta, usually pottery scrap, are added to the clay. This also increases the strength of the clay, reducing the possibility of it shrinking abruptly during molding.

History in Russia

One of the branches of ancient Russian pottery was the production of glazed dishes.
Remains of such dishes are found at excavations of ancient settlements. In rural areas it is much less common. Most of the finds of implements in the form of glazed ceramics from the 10th – 11th centuries are found in the territory of southern Russian cities (Chernigov, Kyiv, Vyshgorod). Single-tier and two-tier pottery forges were used in the production of ceramics. The Byzantine trend had a significant influence on art. During excavations near the St. Sophia Cathedral, dishes were found with a color and a characteristic rim, but the nature of origin is undoubtedly recognized as Russian. These finds indicate that Russian craftsmen, using local raw materials, imitated Byzantine potters. However, such imitation can be traced only in products of the 10th-11th centuries. Later finds were made in the tradition of classical circular ceramics.

Glazed pottery was also found in Novgorod. It is distinguished by a mottled pattern with alternating brown, green and yellow colors. Such utensils include pots and vessels. Spotted watering remained popular until the 16th and 17th centuries. But the traditions of watering have not been lost, and materials obtained in Moscow and the Moscow region are proof of this.

Until the 14th century, wall tiles were somewhat popular in Pskov. It was used to cover the roofs of Orthodox churches. Most likely, the facing tiles and tiles came from it. Nowadays, monuments of glazed ceramics can be found on the territory of the Pskov-Pechersky Holy Dormition Monastery. Ancient tombstones of priests, as well as galleries built into the walls, were made from it. Pskov ceramics differ not only in physical properties, but also in shape.

The famous Gzhel is a separately developing direction. For the first time, Gzhel as an art was mentioned in the Spiritual Charter of Ivan Kalita (1328), but excavations prove that the local population has been engaged in pottery since the 11th century.

Band ceramics.

A later invention was the ring molding technique, in which the vessel was built from several clay strips. A flat, hand-shaped clay base was surrounded by a thick strip, and then pressure and smoothing achieved a strong connection between the base and the strip. The remaining strips were added until the pot reached the desired height and shape. To facilitate the process of building and smoothing the walls, a rounded stone was sometimes placed inside the pot, and the outside surface was treated with a spatula. This technique produced beautiful pottery with walls of uniform thickness. The band pottery method is reminiscent of the technique of weaving baskets from long fibrous ropes (or bast), and it is possible that the band pottery technique has its origins in this method.

Improvements in the tape technique led to the molding of the pot on a small piece of reed matting or a curved shard (a fragment of a broken vessel). The mat or shard served as a base during the construction of the pot and as a convenient axis of rotation, thanks to which the vessel turned easily in the hands of the potter. This manual rotation gave the potter the ability to continuously smooth the pot and symmetrically align the shape as it was built. Some primitive peoples, such as the American Indians, did not create anything more progressive than this technique, and all their ceramics were made by this method. Large jugs for storing food were made using the belt method even after the invention of the potter's wheel.

Precautions when working with clay

Remember to take some precautions :

Study the instructions for materials and equipment.
Remember that the oven you are using is hot and you need to be careful with it.
Be careful when shaping the clay to avoid injuring yourself.
Learn what chemicals are in everything you handle.

Many people get great pleasure from making ceramics at home, and in this article we tried to tell you how to do it. If you want to get into pottery and are worried about whether what you do will make the right impression on someone, then just don't think about it. Improve your technique and always create to the maximum of your capabilities, and you will end up with unique clay products that will create coziness and comfort in your home, add color and festivity to your everyday home environment, and emphasize your individuality.

Potter's wheel.

The invention of the potter's wheel dates back to approximately the end of the 4th millennium BC. Its use was not immediately widespread; some regions adopted new technology much earlier than others. One of the first was Sumer in Southern Mesopotamia, where the potter's wheel began to be used around 3250 BC. In Egypt it was already in use by the end of the Second Dynasty, around 2800 BC, and in Troy, wheel-made pottery was discovered in the Troy II layer, c. 2500 BC

An ancient potter's wheel was a heavy, durable disk made of wood or terracotta. On the underside of the disk there was a recess with which it was mounted on a low fixed axis. The entire wheel was balanced so that it rotated without wobbling or vibration. In Greece, the wheel was usually rotated by an apprentice potter, adjusting the speed at the command of the master. The large size and weight of the wheel ensured a fairly long period of its rotation after launch. Having an assistant turn the wheel allowed the potter to use both hands in shaping the vase and give the process his full attention. The foot potter's wheel does not appear to have been used until Roman times. In the 17th century the wheel was set in motion by means of a rope thrown over a pulley, and in the 19th century. The steam-powered potter's wheel was invented.

The process of making a pot on a potter's wheel begins with kneading the clay to remove air bubbles and turn it into a homogeneous, workable mass. Then the clay ball is placed in the center of the rotating circle and held with bent palms until the circle moves evenly. By pressing the thumb into the middle of the clay ball, a ring with thick walls is formed, which is gradually stretched between the thumb and the rest of the fingers, transforming into a cylinder. This cylinder can then, at the request of the potter, open into the shape of a bowl, stretch out like a long pipe, flatten into a plate, or close to create a spherical shape. At the end, the finished product is “cut off” and placed to dry. The next day, when the clay dries to a hard crust, the vessel is turned upside down into the center of the circle. On a rotating wheel, the shape is sharpened, or cleaned, by cutting off the unnecessary part of the clay, for which tools made of metal, bone or wood are usually used. This completes the molding of the product; the vessel is ready for decoration and firing. The leg and other parts of the vessel can be dressed and ground separately and then attached to the body of the vessel with clay coating - liquid clay used by the potter as a fastening material.

Casting.

The casting technique is used to create mass-produced ceramics. First, a plaster mold is made according to the model to be reproduced. A liquid clay solution called casting mud is then poured into this template. It is left until the gypsum absorbs moisture from the solution and the layer of clay deposited on the walls of the matrix hardens. This takes about an hour, after which the mold is turned over and the remaining solution is poured out. The hollow clay casting is finished by hand and then fired.

In ancient times, soft, pliable clay was pressed into a mold by hand rather than poured as in the casting technique. The production process began with the molding of the model itself. The clay sample (patrix) made by the master was created taking into account both the final use of the vase and the intermediate production stages. Most of these sculpted vases have the molded part attached to a piece, such as a mouth, shaped on the potter's wheel. Therefore, the production of patrix was limited to only this molded part.

Drying

Drying is the most critical stage, since both the mechanical strength of the product and its decorative characteristics depend on the correctness of its implementation.
Of course, the correct distribution of the glaze is extremely important, on which the product’s resistance to water and chemical agents depends. Drying is a prerequisite for ceramic production. Conveyor, radiation and chamber dryers are used for it. The temperature throughout the process should not exceed 70-90 °C. The only exception is tiles. The ceramics in this case are very thick, so in some cases it is possible to use high-temperature conditions for a short time.

Burning.

The technique of treating dried clay with heat to transform it from a soft, brittle substance into a hard, glassy material was discovered ca. 5000 BC This discovery was undoubtedly accidental, perhaps the result of a fireplace built on a clay base. Probably, when the fire went out, people noticed that the clay base of the hearth had become extremely hard. The first inventive potter could duplicate this phenomenon by molding something from soft clay and placing it in the fire, and then find that the fire did not damage his product, but rather gave it a hard, stable shape. This is how the technique of ceramic firing could appear.

Primitive methods.

Ancient potters did not use kilns; they collected dried clay vessels in a small pile and covered them with any combustible material at their disposal: wood, charcoal, brushwood, straw or dry manure. Among the primitively communal tribes of Africa and North and South America, this practice continues to this day. Because the pot pile is not at the same temperature and some are not heated enough to sinter the clay, this type of firing produces uneven results and causes unusable pottery. When unbaked pots are filled with water, they become soggy and turn back into soft clay. The color of this ceramic is unpredictable, as some areas are completely exposed to the oxidation process, and others - to a much lesser extent. Therefore, some products turn out to be brownish-red, while others are grayish or black.

Burning

The second most important technological stage is ceramic firing. The goal is to mold a shard with precisely specified physical and chemical properties, fixing the coloring composition and glaze on the surface. Firing is important because during its course many physical and chemical processes occur, which determine the main consumer qualities of the product. Typically, firing is carried out in two stages, but if paint has been applied to the surface of the glaze, the so-called muffle firing is carried out (third stage).

The first stage is carried out at temperatures from 900 to 1250 ° C (depending on the type and grade of ceramics). The second stage requires a temperature range from 1020 to 1410 °C. The latter value is used exclusively for porcelain. Other ceramics are rarely fired in this mode, as the risk of cracking is high. If we are talking about the average red clay, then products made from it are often “burnt” once, at a temperature no higher than 960-1020 degrees Celsius.

Two types of ceramic furnaces can be used for firing: periodic (furnaces) and continuous. There are a lot of varieties of the latter, but the most common are tunnel and roller ones.

Bake.

This is a specially built chamber for firing ceramics, allowing the potter to have greater control over the process than would be the case with open fire firing. Usually the firebox is separated from the place where the dishes are placed. To control the fire, place and move products, monitor firing and adjust air draft, holes are provided in the furnace.

During the first stage of firing, moisture is gradually removed from the clay. Firing is carried out slowly to avoid cracking of the products. When the temperature reaches 600° C, the clay is completely dehydrated. It becomes a uniform red color and a brittle, porous and absorbent (capable of absorption) shard. During the second firing, after glazing, the temperature reaches 600–900° C. If air flows freely into the kiln during firing, the clay is oxidized and all carbonaceous substances are removed. If there is no air in the kiln, the clay shard will be black, “restored.”

How to dry clay?

Unless you are working with a kiln, you are most likely going to air dry your clay or bake it in the oven. There are several ways for each of them.

For baking in the oven:

Preheat oven to desired temperature.
Place the clay piece there on a tray.
Bake for the required amount of time.
Check the hardness of the product.

It's simple, but again, the heat isn't high enough for porcelain or earthenware.

For air drying:

Place the product in a safe place.
Wait. This may take up to 24 hours.
Check the product for hardness and give it more time if necessary.
If you're air drying, use fine-grit sandpaper to remove any minor imperfections before moving on to painting.

Drying pottery takes time, but proper drying techniques can help you avoid mishaps.

Underglaze decor.

As the name implies, underglaze decor is applied to the piece before it is covered with a clear glaze. Paints are made using oxides of cobalt, nickel, chromium, manganese, iron, etc., which give the glaze the desired colors. The oxides are mixed with substances, which must melt during subsequent hot processing, thus bonding with the shard. The decor is applied by hand painting, transferring the design using the decalcomania method, silk-screen printing (i.e. using a silk mesh as a stencil) or spraying paint through other types of stencils. The decoration method, called sgraffito, involves painting the entire surface of the product with an engobe (liquid clay coating) of a different color than the product itself, and then scratching the intended pattern through this coating. Underglaze decor is extremely durable, as it is protected from wear and chemical attack by the glaze covering it.

Painting clay products

You can paint the clay with acrylic or latex paint if it is allowed to air dry. It is important that you follow certain rules here too.

Some painting tips:

Make sure that if you are firing clay, the paint is suitable for kiln use.
Some paints do not require firing, which can sometimes be a convenient option.
Choose a paint that matches the required temperature, as air-dried clay cannot be fired.
Apply paint with brushes, sponges or other methods.
Allow the paint to dry according to the paint instructions.
If you are going to kiln cookware for food and liquids, use paint and sealant first, and then start firing after drying.
If you are using a kiln, also use glaze to fully seal the paint.

Painting will add a unique touch to your artwork, and while it may not be necessary at first, you can really benefit from it if you have some interesting painting ideas. Some also prefer to paint the products after baking in the oven, you decide for yourself what you like best.

Overglaze decor.

In this case, pigments composed of coloring oxides and materials that leave a metallic residue are applied over the fired glaze. Since overglaze paints are fired at fairly low temperatures (700–870° C), a variety of colorants can be used that cannot withstand the higher temperatures required for underglaze firing. Metal decor consists of either metal salts or very small metal particles with some kind of binder that forms a consistency suitable for painting or silk-screen printing. During the firing process, the binder evaporates, leaving a metal film on the surface of the product. If this film is very thin, the metal particles have not so much a metallic but a pearlescent tint; such a covering is called a chandelier. The color of the chandelier can vary by using different metals. If the pigment is applied in a thicker layer, the result is a shiny metallic surface, which is usually achieved using gold, silver and platinum. The pigment containing sprayed metal particles is usually applied in a fairly thick layer using the silk-screen printing method, which produces the most durable metal decor. Since the surface of such products becomes dull after firing, they should be polished.

see also

DECORATIVE ARTS; TERRACOTTA; articles on ceramics from countries around the world.