Boiled wood. Bound moisture in wood

It is estimated that living tree together with the trunk, branches, roots, bark and leaves, it consists of 65-85% water. Moisture supplied by the roots from the soil maintains the viability of plant cells. But moisture in nature is needed not only by a living tree, but also by a dead one. Thanks to the water it contains, it breaks down quite quickly, turning into a natural fertilizer needed by living plants. If this did not happen, then many of the world's forests would be buried under the trunks and branches of dead trees.

But then the wood falls into the hands of a master woodworker, and the moisture it contains begins to play a negative role instead of a positive one. The surface of raw wood after turning, sawing and cutting becomes fleecy and difficult to finish. It is very difficult to sand, varnish and paint coatings crack and crumble. After drying, the product warps and becomes covered with deep cracks. They arise in wood due to the uneven drying of its various layers - the upper ones dry out and decrease in volume much faster than the inner ones.

The wood cracks along the core rays. At the end of a cracked log or ridge, it is clearly visible that basically all the cracks run in the radial direction and only a few minor cracks can be located at the boundary of the annual layers. The more the wood dries out, the more numerous and deeper the cracks that appear in it. Soft and light wood usually dries out less than hard, dense and heavy wood. In addition, soft wood dries much faster than hard wood and warps and cracks less. According to the degree of drying, the wood of various trees can be divided into three groups: low drying - spruce, juniper, willow, cedar, poplar; medium-drying - elm, pear, oak, linden, alder, aspen, rowan and ash; highly drying trees - birch, larch, apple tree, lilac and maple.

Even in ancient times, people noticed that wood, only after removing moisture from easily degradable raw materials, turns into durable and durable material. Dwellings were built from it, tools and various household utensils were made. But how to dry wood so that cracks do not form in it?

Over the course of many centuries, folk craftsmen have developed their own techniques for drying wood, which are sometimes striking in their unexpectedness and wit. The trees were dried directly in the forest or in the yard under a canopy, in a heated room, in a Russian stove, in soil, shavings, in grain, boiled, soaked in water... When using one or another drying method, the craftsmen necessarily took into account the type of tree, its structure , hardness, density and dimensions of workpieces. When selecting suitable material for the blanks, they knew that twisted wood with twisted wood layers is less susceptible to cracking than straight-layered wood. They knew that the part of the tree trunk located closer to the root, the so-called butt, has stronger wood that is less susceptible to cracking than the rest of the trunk. Wood raw materials were also dried taking into account the conditions in which the finished product would be located. For example, wood was dried more thoroughly for carpentry work than for construction work.

The moisture found in the wood of a freshly cut down tree is divided into capillary, or free, and colloid-bound, or hygroscopic. Hygroscopic moisture directly enters the wood cells. Capillary moisture, called “forest moisture” by folk craftsmen, fills the intercellular space and wood channels. During the drying process, capillary moisture is first removed, and then hygroscopic moisture. In practice, absolutely dry wood is not found.

Any wood contains a certain percentage of moisture. Therefore, in woodworking production when practical definition The degree of moisture content of wood is usually indicated as the percentage of water relative to 100 g of conditionally absolutely dry wood. The wood of a freshly felled tree is called green wood. It usually has a very high degree of humidity. For example, in spruce and pine it can reach up to 150%. Wood that has been in water has a humidity level of about 200%. They call it wet. Wood containing 18-23% moisture is called semi-dry. This means that per 100 g of absolutely dry wood there are 18-23 g of water. And wood that weighed 100 g in an absolutely dry state will already weigh 118-123 g at the indicated humidity. Air-dry wood has a moisture content of 12-18%, and room-dry wood - 8-12%. Typically, wood with a moisture content of 8-12% is used for artistic and carpentry work, and 12-18% for carpentry. For example, a chair or table should be made from dry wood, and carved frames from air-dried.

How is wood dried, how is it transformed from raw material into a wonderful solar material?

Folk craftsmen harvested wood in specially designated forest areas; cutting down a tree in the forest without permission was considered great sin and even a crime. Zago-

The harvest began in late autumn, as soon as the last leaf fell from the trees, and ended with the beginning of the spring sap flow. At this time, there is very little “forest moisture” in the trunks of torpid trees. Therefore, they dry faster and crack less. Nature itself dried the wood, and man only finished drying it using one of the known methods.

Drying of wood in the forest directly on the root was carried out in spring and summer. A wide ring of bark was removed from around the tree trunk intended for felling. Moisture from the soil stopped flowing into the crown. The leaves and needles absorbed the moisture remaining in the trunk, which evaporated simultaneously with drying. A tree with a dried trunk was felled, the branches were cut off, and then bucked, that is, sawed into logs. Nowadays, harvesters use this method to dry pine before rafting down the river. Drying standing trees increases the buoyancy of the rafted wood, and therefore reduces its losses along the way.

In the spring, when the young foliage on the trees was in full force, Bogorodsk craftsmen went to the forest to harvest linden wood for carved toys. The branches of the fallen linden tree were cut off and the bark was removed from the trunk along approximately two-thirds of the length of the entire tree. The upper part of the tree with branches, branches and leaves (crown) was left untouched. The considerations were very simple. The foliage of a cut down tree does not wither immediately, but continues to struggle for life for a long time, as if using powerful pumps 131 to draw in the life-giving moisture located in the tree trunk. In two weeks, this natural pump pumped out so much moisture from the trunk that it was impossible to remove it during normal drying. outdoors it would take several months. After two weeks, the linden trunk was sawed into ridges up to one and a half meters long. Barked and dried linden ridges, the so-called lutoshki, were brought home and dried in the yard under a canopy, laying them on a flooring raised above the ground. By autumn, linden wood was already quite suitable for all kinds of carving work. Some of the wood was put into use, and the rest continued to be dried in free air.

Atmospheric drying or drying in free air is simple and accessible, but a tree located under a canopy that protects it from rain and direct sun rays, dries very slowly - from several months to several years. Wood dries better in summer than in spring, autumn and winter. But if the summer is rainy, it not only dries poorly, but can become moldy and even rot. If the weather is favorable, the wood can be dried to an air-dry state (12-18% humidity).

The trunks of soft deciduous trees are debarked, that is, the bark is removed from them, and placed on racks. Sometimes strips of bark are left at the ends. The same rings are left at equal intervals in the middle. The bark is not completely removed from the trunks of hardwood trees, such as apple trees and maples. To prevent the wood from cracking due to uneven drying, the ends of the trunks are painted over or whitened. Putties that close the pores of wood are made from a mixture of drying oil and fluff lime or tree resin and chalk. When drying small trunks, the ends are covered with a thick layer of thick oil paint.

Chamber drying is widely used in woodworking enterprises. In special drying chambers The wood is treated with superheated steam and flue gas. Wood dried in chambers has a room-dry humidity (8-12%) and is used for carpentry, turning and carving. It takes from three days to a week to dry soft wood, such as pine, linden or spruce. Solid oak, beech or elm wood should dry in the chamber from two weeks to a month. But even during chamber drying, the appearance of cracks is not excluded. Therefore, scientists are constantly looking for better and faster ways to dry wood.

IN last years drying chambers operating on currents were created high frequency. In such chambers, wood is placed between two brass electrode grids. Current is supplied to the electrodes from a high-frequency generator. IN electric field wood dries almost 20 times faster than in a steam chamber. Valuable hardwood is dried in this way.

Drying wood by steaming has been used by folk craftsmen in the distant past, since it was invented Russian stove, which became the prototype of the modern drying chamber.

If for some reason it was not possible to prepare wood in the spring, it was quickly dried in Russian ovens. The wood was steamed in large cast irons. Raw wood was placed in cast iron, and a little water was poured into the bottom. Then the cast iron was covered with a lid and placed in a heated oven. To prevent the heat from leaving the oven, it was closed with a damper. In the morning, the wood was removed from the cast iron and dried at room temperature.

Another, simpler method of drying wood was also used. After the next fire, the ash was raked out of the Russian stove and the floor was cleanly swept, on which wooden blanks were placed on the butt. With the damper tightly closed, the wood was kept in the oven until the morning. By morning the wood had dried well and at the same time acquired a beautiful color. After steaming, white linden in its raw form turned golden, and alder wood turned light chocolate.

By boiling in fresh water You can remove “forest moisture” from soft wood of linden, pine, alder and other trees. Simultaneously with the release of capillary moisture from the wood,

it becomes much softer than when dried. Taking this into account, woodworkers carved spoons and ladles from steamed wood immediately after removing it from hot water. M. Gorky compares steamed wood with oil in “The Story of the Extraordinary”: “... an old man is sitting on a stump by the fire, a cauldron is boiling over the fire in the stones, - logs of wood are softening in the cauldron... The handmade old man is bent over, cutting spoons... He acts quickly with the knife, shavings splash on his knees and legs. The logs are raw, they cut easily like butter, there is no creaking from the knife. And the water is gurgling in the cauldron.”

Spoons and various thin-walled utensils cut from boiled wood dry out so quickly that cracks do not have time to appear.

Boiling wood in salt water also prevents it from cracking. In addition, salt reliably protects wood from the penetration of putrefactive microbes into it. In the woodworking workshops of timber industry enterprises that produce troughs and other dugout utensils, finished goods from linden, aspen and willow are boiled in a 25% solution of table salt.

Small pieces of hard and soft wood can be processed at home. Raw wood is placed in a deep pan and filled to the top with salted water at the rate of 4-5 tablespoons of table salt per liter of water. The wood is simmered for two to three hours, then removed from the salt water and dried at room temperature. 133

Soaking wood in water reduces the appearance of cracks during subsequent drying. Logs were stored in water, which protected the wood of freshly cut trees from rotting during the season. Often, oak logs were immersed in the bottom of a stream or river (the water needed to be running). To prevent them from floating, a weight was tied to them. Apparently, black woodworkers thought of soaking wood before drying. bog oak, which they sometimes raised from the bottom of forest rivers and streams. Having lain in water for dozens or even hundreds of years, the bog oak was hard as stone, and when dry it did not become covered with cracks.

Boiling small pieces of hardwood in oil and drying oil not only prevents the appearance of cracks, but also enhances the decorative expressiveness of the material. Blanks for small carved items from apple, boxwood, pear and oak are boiled in natural drying oil, linseed, cotton, wood (olive) oil. During cooking, oil displaces moisture from the wood into the air, filling the intercellular spaces. The wood boiled in oil or drying oil is then dried at room temperature. Well-dried wood acquires additional strength and moisture resistance, and is perfectly sanded and polished.

Drying logs in a vertical position on dry ground is known in the southern regions of our country. For example, Uzbek carvers dried wood under a canopy in the open air.

Logs intended for drying were placed vertically so that the lower end rested on dry soil. The moisture in the logs gradually descended along the fibers through capillaries and the dry earth greedily absorbed it.

Elder Master musical instruments Rakhimdzhan Kasymov said that in the recent past, craftsmen practiced drying wood in the ground and river sand. First, a rough blank was hewn out of the trunk of a freshly cut tree. Then it was buried in the ground somewhere under a canopy, so that even the rare rain in Central Asia could not moisten the soil. The tree was kept in the ground for several years, but often only one year was enough. After a certain period of time, the workpiece was torn out of the ground and dried indoors. The drying period was determined by the condition of the wood, which they were able to determine with great accuracy. The color of the wood, the nature of the sound made by the workpiece when lightly tapping it with a knuckle, gave the experienced craftsman accurate information about the readiness of the wood for further processing.

Small pieces of hardwood can be dried quite quickly artificially in river sand. At the same time, they acquire a golden brown color.

Interesting decorative effect can be achieved by drying ready-made carved products. A layer of clean river sand is poured into the cast iron. Blanks are placed on top, which, in turn, are covered with a new layer of dry sand. In this way, cast iron is filled to the top, making sure that the workpieces do not touch its walls. Loaded cast iron without a lid is placed under the stove. The closer it is to the burning wood, the faster the drying will go. But there is a danger that the wood will begin to smolder after some time. At the same time, if cast iron is placed too far from the fire, the wood will dry slowly. Optimal distance From fire to cast iron, craftsmen determine experimentally. As the wood dries, a golden tan gradually appears in areas facing the fire. It smoothly transitions into the natural color of the wood on the opposite side. Often this is exactly the effect wood carving artists achieve when decorating finished carved products. But if you need to get a uniform color, cast iron is turned around its axis from time to time, exposing first one side or the other to the fire. If they want to get clean, dried wood (without tan), cast iron with sand and blanks is placed in the oven after heating overnight. You can also dry wood in sand on a stove or fire, using cans, old pots, and buckets instead of cast iron.

It is known from written sources that ancient Greek sculptors dried valuable wood by burying it in dry rye. Drying wood in grain was well known in Rus'. The wooden blank was buried in grain closer to spring. Over the course of several weeks, the grain absorbed all the “forest” from the wood.

new moisture." The wood prepared in this way was kept at room temperature, and then boldly put into use, without fear appearance of cracks. It was believed that drying raw wood in grain several weeks before sowing had a beneficial effect on the quality of the seed. The grain, filled with life-giving moisture, seemed to awaken from winter hibernation and germinate faster once in the ground.

Burying wood in shavings is a widely known and reliable way drying wood, used by turners and woodcarvers. The turner immediately buries raw turned parts in shavings obtained during turning or prepared in advance. A woodcarver buries an unfinished carved board or sculpture in the shavings. They dry evenly along with the shavings. This measure prevents the product from warping and cracking, especially during a long break in work.

Master woodworkers have always been inexhaustible in their invention, especially when it was necessary to obtain high-quality material. Noticing that even in severe frosts the temperature inside the dung heap constantly remained quite high, they began to bury oak ridges in it. In the spring, the ridges were washed in running water and dried under a canopy in the open air.

One more thing should be said the original way drying wood - drying on a cement floor, based on the ability of concrete to intensively absorb moisture. Wet 135 wood is laid on a dry concrete floor. During the day, each workpiece is turned over so that alternately one or the other edge is adjacent to the cement floor.

Successful drying of wood largely depended on the size and shape of the workpiece, the presence or absence of sapwood. A craftsman who had a good knowledge of the structure and physical and mechanical properties of wood could, with the help of an axe, saw, drill and chisel, direct the drying process in the right direction at his own discretion.

It is well known that it is especially difficult to dry logs, logs and lumber that have a core inside. As a rule, when dried, they crack almost to the very core. The logs of many log buildings are usually riddled with numerous cracks. However, you can still find log buildings that do not have any noticeable cracks.

How did the carpenters manage to dry the logs so well? It turns out that there are still cracks in the logs, only they are hidden from our eyes. There is one large crack for each log, but they are skillfully camouflaged inside log house. Before drying, the carpenter made a notch along each log with an ax. The depth of the notch was approximately one third of the distance from the surface of the log to the core. After the wood dried, one deep crack formed at the notch site, and the remaining sections of the log remained smooth.

kimi. One big crack seemed to absorb dozens of smaller ones, concentrating the shrinkage in the notch zone. When laying logs in a log house, carpenters placed them with the cracks facing down. Using the same principle, Indian treemakers dry boxwood, which is known to be very hard and prone to severe cracking. The boxwood log is sawed down to the core, due to which shrinkage during drying is always concentrated in the cut area.

It is known that split wood dries quickly and without cracks. If you split a log or ridge in half, you get a plate (half). The half-growing tree expels much faster than the ridge, not only because its mass becomes half as much, but mainly because air access is opened to the cut annual layers. If the half is dried unevenly, then a deep crack may develop from the core. By splitting a half in half, you get a quarter (in the old-fashioned way, “quarter”). Unlike a plate, a quarter very rarely develops cracks when it dries out.

The properties of split wood were well known and skillfully used by master carvers from Troitse-Sergievsky Posad, Moscow province. They split the linden ridge, depending on its thickness, into four or eight parts through the core. Perhaps this technical technique, which arose from the need to avoid cracking of wood, to some extent suggested the plastic solution for many carved toys.

It is quite difficult to dry hardwood that has a core. When it dries, it cracks a lot. Deep cracks reach almost to the core. For example, the wood of a freshly cut apple tree is susceptible to severe cracking. But even the trunk of a dried apple tree - dead wood, after sawing into short ridges and debarking, becomes covered with numerous cracks. The apple tree has light sapwood and a dark core. Masters especially value the core. The core wood is harder and drier, and its pores are filled with a special preservative. Sapwood, on the contrary, is loose and highly saturated with moisture. When the ridge dries, the sapwood cracks first, and then the core. To preserve the valuable core wood, the sapwood is cut with an ax and the ends are greased with paste. After removing the sapwood, the heartwood dries quite well, with almost no cracks.

Raw wood causes a lot of trouble for sculptors, who most often have to deal with ridges of quite impressive size. In order not to depend on the capricious instability of wood in ridges, some sculptors glue together blocks of the required size and configuration from pre-dried bars. Glulam blocks are resistant to warping and cracking, but disruption of the natural direction of the wood layers that form the textured pattern is often detrimental to the artistic merit

sculptures. In a sculpture made from a whole ridge, and not from a glued block, the texture, on the contrary, emphasizes the form and makes it more expressive.

The craftsmen noticed that if the core of the ridge is removed, the appearance of cracks can be avoided almost completely. A hole with a diameter of about five centimeters is drilled in the workpiece along the core. When drying, moisture is simultaneously and evenly removed not only from the upper, but also from the inner layers of the ridge. Having completed work on the sculpture, the holes are plugged with wooden plugs.

The oldest Soviet animal sculptor V. Vatagin wrote in his book “Image of an Animal”: “I chop my sculptures from wood, regardless of whether it is dry or wet. Raw wood is much easier to cut; the chisel cuts more softly into the elastic, raw layer. Cracks will still appear, and then they will need to be repaired. But in some cases, when shaping a stump, the internal layers are exposed, drying occurs more evenly and cracks do not appear or appear in smaller quantities.” As we can see, the sculptor dried the wood simultaneously with its plastic processing.

It is possible that one or two cracks may still appear on a finished wooden sculpture, carved, chiseled or turned product made from well-dried wood. Therefore, every master woodworker must be able to skillfully seal them. The cracks generally run along the fibers, 137 gradually narrowing towards the core. Having hammered a small piece of putty into the crack (plasticine or eglin is possible), it is then carefully removed with a stack or sliver. The putty takes the shape of a triangular prism. To prevent it from sticking to the wood, the gap is sprinkled with talcum powder or tooth powder before molding. Guided by the resulting cast, the master cuts slats with a triangular cross-section from wood. They are commonly called roosters. The prepared slats are lubricated with glue and hammered into the cracks. Small cracks are sealed with special putty (in liquid solution carpenter's glue is poured into tooth powder). The putty is tinted with dry pigments, gouache or tempera to match the color of the wood.

Affordable and universal material. It is often used for construction and interior decoration. But without special preparation, wood will not last you very long. is one of the main stages of preparing wood for use.

An interesting and popular method of drying wood is drying wood by boiling it in salt. Let's look at this method in more detail:

Drying wood by boiling in salt - how does it work?

The tree is natural material With high humidity, in the tree trunk there are capillaries that contain liquid. The tree absorbs this liquid from the soil and from the environment. This liquid contains nutrients in addition to water.

Cannot be used in production. Such wood is difficult to process, does not adhere, and during use can change its shape, which will lead to cracking and the appearance of cracks in the product. The wood must be thoroughly dried before use. The ideal humidity for a material such as wood is considered to be no higher than 10-12%. In principle, wood dries perfectly in natural conditions and does not require any additional effort. It is enough to place the wood in a well-ventilated room and forget about it for a while. But this causes a number of inconveniences: firstly, it takes a long time, and secondly, you need to have a room with enough space to dry the required amount of material. How can you facilitate and speed up the process of drying wood?

One of the most available methods is the cooking of wood. You can boil wood in ordinary fresh water, but boiling wood in salt water has a greater effect.

Drying wood boiling in salt speeds up the drying process and improves the quality of the wood. The fact is that boiling wood in salt water speeds up the process of removing the juice contained in the wood cells, which in turn reduces the total time required to dry the wood. Boiling wood in salt makes it soft, it dries faster, which helps prevent cracking and changing the shape of the material during further drying. Also, boiling wood in salt helps improve the appearance of the tree.

Boiling wood in salt at home

Drying wood by boiling it in salt is one of the methods that can easily be used at home.

Small pieces of wood, wooden parts or blanks can be boiled using a large saucepan and a regular household stove. We make the solution in the following proportion: for one liter of water, about five tablespoons of salt.

For large quantities of wood, specially equipped baths are usually used. Craftsmen who use this method of drying wood often make their own bathtubs with built-in heating elements.

A fire is also suitable for warming up the container with the material.

For more information about boiling wood in salt water, watch the video. Enjoy watching!

Irina Zheleznyak, Staff correspondent for the online publication "AtmWood. Wood-Industrial Bulletin"

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To determine the quality of lumber, there is such a thing as wood moisture content. It indicates the quantitative ratio, expressed in %, of the water content in the wood structure in the mass of the entire sample.

Features of bound moisture

Wood is a porous material; it is riddled with channels and pores; water enters there, feeding the plant with the minerals necessary for growth. This moisture is called free moisture. And it is removed from the wood structure even under atmospheric drying conditions.

But in addition to free moisture, there is also bound moisture in wood. This is the part of the water that is found in the cells and tissues of the tree; it takes part in the formation of lumber as a reliable and durable type of building materials.

This moisture is more difficult to evaporate, and in many situations it is impossible, since it is located in micropores that remain inaccessible even with intense heating by an air flow.

If, when free moisture evaporates, lumber does not change its physical and mechanical properties, then in the case of bound moisture evaporation, the wood undergoes changes:

significantly changes its structure,
loses strength
linear dimensions change,
the shape changes.

Bound moisture can occupy a significant proportion of the total. If the total moisture content of the wood is more than 30%, then this indicates the presence of free moisture in it, so the lumber still needs to be dried.

The wood is dried for the purpose of its subsequent processing and imparting the necessary qualities. The wood is boiled to prevent cracking and protect against the penetration of putrefactive microbes.

There are 2 most common methods of digestion:

In salt water;
In oil;

Drying in a hydrophobic solution: urea (urea) is also used.

Drying wood in salt water

Wood is boiled in salt using a 25% saline solution. The wood must be placed in a container filled with saline solution and cooked over medium heat for two to three hours. The time may vary depending on the amount of wood. Wood drying takes place in salt water; the material heats up, allowing bound moisture to be removed with minimal damage to the geometry of the lumber.

Boiling wood in oil and drying oil

Boiling in oil not only prevents cracking in wood, but also enhances the expressiveness of the material. During cooking, the oil pushes air and water out of the wood, entering the intercellular spaces. Next, the wood is dried, as a result it can be easily sanded and polished.

The cooking technology is quite labor-intensive and requires direct human work and further drying. It is used for small samples, incl. spilov. On an industrial scale, drying with salt or oil is completely impractical. It is mainly used in domestic conditions. In cases of even small production, drying chambers such as are used. Small volume and industrial use. Volume from 1 - 27 cubic meters.

Processing wood with clay.

If certain areas of wood on a tablet are shielded from direct exposure to fire not by metal, but by clay, then due to the high plasticity of clay, it becomes possible to create decorative designs of any complexity.

Any clay that is thoroughly cleaned of foreign impurities - sand, pebbles and dried grass residues - is suitable for work. This is how you can clean clay. Fill the bucket with crude clay to about one-third of its capacity and fill it with clean water. Stir the clay thoroughly until completely dissolved in water. Then let the solution sit. Chips and blades of grass will float, and sand and pebbles will settle to the bottom. Once the water is clear enough, carefully drain it. Any floating debris will be removed along with the water. Carefully scoop out the liquid clay remaining in the bucket into the prepared clean container. In this case, there is no need to touch the bottom layer, which contains settled sand and pebbles. Let the liquid clay poured into the vessel sit again and drain off the excess water. If necessary, elutriation can be repeated in the same sequence. The exhausted clay needs to be slightly dried. The most convenient clay to work with is one that has the thickness (consistency) of Vaseline or toothpaste.

Using clay on the surface of wood, you can burn a dark design on a light background or, conversely, a light design on a dark one.

Dark drawing on a light background
Apply a layer of clay about 5 mm thick to the surface of the wood. The clay must be allowed to dry enough that it can be easily cut with a knife without sticking to it. You need to cut out the design on clay using stacks of loops. They are easy to make with your own hands. Bend steel wire or springs from an old clock into brackets various shapes and magnitude. Then screw them with soft copper wire to wooden cuttings. The free end of one of the cuttings must be sharpened and used as a scribe when applying an auxiliary design to the clay. Using the lines of the drawing as a guide, cut deep grooves in the applied layer of clay. Wood should be exposed at the bottom of each groove. Without waiting for the clay to dry, burn the areas of wood that have been cleaned with the stack. After finishing firing, remove the clay with a wooden scraper and rinse the wood with clean water.

Light drawing on a dark background
If clay is applied to the surface of wood not in a continuous layer, but in narrow rolls, then after firing and removal of the clay, a light contour pattern will clearly appear on the dark scorched background. To apply clay to wood, use a rubber bulb or an elastic plastic bottle. Since the clay used in working condition should not have great fluidity, it is quite difficult to get it into the bulb through the tip. To make this task easier, cut a round hole in the pear, which, after filling it with clay, must be plugged with a suitable cork. Drill a hole in the lid of the plastic bottle and insert a metal tube into it. After unscrewing the stopper, fill the bottle with liquid clay.
Squeezing clay from a bottle or pear, apply the intended design to the surface of the wood. By changing the pressure on the walls of the bulb or bottle, you can apply rollers of various widths. By moving them at different speeds, the thickness of the applied clay layer is adjusted.

After applying the clay, begin firing immediately. By firing the wood, you will simultaneously dry the clay. You need to burn it very carefully, barely touching the flame of the burner to the wood. The clay will serve as a kind of indicator. If you want to get a clear pattern, firing should be stopped without waiting for the clay to dry completely. If, according to the plan, the design should not be too contrasting, increase the firing time until the clay dries completely. The clay at the edges will become slightly hot and scorch the edges of the picture, destroying the sharp transitions from light tone to the dark. But at the same time, you need to remember that if fired for too long, the clay can become hot and the areas of wood located under it will become charred, nullifying all the work.

When firing is complete, the dried clay will peel off easily from the wood. If, after removing the clay, dirty clay stains remain on the wood, it must be washed with clean water and wiped dry with a soft cloth.

Boiling in fresh water - how does the process work?

By boiling in fresh water, you can remove “forest moisture” from softwood, pine, alder and other trees. Simultaneously with the release of capillary, it becomes much softer than in the dried state.

Taking this into account, woodworkers carved spoons and ladles from steamed wood immediately after removing it from the hot water.

M. Gorky compares steamed wood with oil in “The Story of the Extraordinary”: “... an old man sits on a stump by the fire, a cauldron is boiling over the fire in the stones, - the logs of wood are softening in the cauldron... The handmade old man is bent over, cutting spoons... He acts with a knife quickly, the shavings are so and splashes on his knees, on his feet. The logs are raw, they cut easily like butter, there is no creaking from the knife. And the water is gurgling in the cauldron.”

Spoons and various thin-walled utensils cut from boiled wood dry out so quickly that cracks do not have time to appear.

and their description

Boiling in fresh water

Boiling in fresh water removes “forest moisture” from the soft wood of linden, pine, alder and other trees. Simultaneously with the release of capillary moisture, the wood becomes much softer than in the dried state. Taking this into account, woodworkers carved spoons and ladles from steamed wood immediately after removing it from the hot water.
Spoons and various thin-walled utensils cut from boiled wood dry out so quickly that cracks do not have time to appear.
Boiling in salt water

Boiling wood in salt water also prevents it from cracking. In addition, salt reliably protects wood from the penetration of putrefactive microbes into it. Products made from linden and willow are boiled in a 25% solution of table salt.

Soaking in water

Soaking wood in water reduces the appearance of cracks during subsequent drying. Logs were stored in water, which protected the wood of freshly cut trees from rotting during the season. Often, oak logs were immersed in the bottom of a stream or river (the water needed to be running). To prevent them from floating, a weight was tied to them.
Having lain in water for dozens or even hundreds of years, the bog oak was hard as stone, and when dry it did not become covered with cracks.

Boiling in oil and drying oil

Soot, or soot, is the smallest particles of smoke that have settled on any surface.
Smoking is a simple but quite effective method of wood, which is often used modern masters. Its essence is as follows.

Suppose you need to decorate a wooden button using this method. Prick a button made from linden, aspen or wood onto the tip of an awl from the wrong side and place it over the flame of a burning candle. Either bringing the wood closer to the smoky flame or moving away from it, you can paint with soot like a brush, getting “strokes” of any tone - from light gray to black. The soot pattern adheres to the wood very weakly. To secure it, dip the button in liquid clear polish. After the first layer of varnish has dried, apply two more layers in succession using the same method. Under varnish, wood treated with soot acquires a warm tint, and soft “strokes” with smooth transitions resemble the color of the horny shell of a turtle. Therefore, this technique of decorating wood among folk craftsmen is called “turtle-like.”

Using a stencil using the smoking method, you can apply ornamental and plot designs to wooden surfaces. It is advisable to cut the stencil out of paper with foil glued on one side, for example, from a tea package. Using a stencil you can only apply silhouette images. Where the foil remains intact, the wood after smoking will be light, and opposite the slots will be dark. If the stencil is applied to a cylindrical or conical surface, then it is secured with threads or thin soft wire. On a flat surface, lightly grab the stencil in the corners with glue. If there are allowances left along the edges of the wooden workpiece, which will be cut off later, then the stencil is secured with buttons or small nails. The product or workpiece covered with soot should be above eye level. Using a smoke candle, apply soot evenly to the stencil and to the surface of the wood in the slots. When finished smoking, carefully remove the stencil from wooden surface. A clear silhouette pattern will remain on it. It needs to be secured. If the object to be decorated is large and the dipping method cannot be used, apply several thin transparent layers of varnish using a spray bottle. One stencil can be used many times, after first removing any soot that has settled on the foil with a soft cloth.

Decorated firing treatment

Using open directed fire gas burner or blowtorch you can not only enhance the expressiveness of the wood texture of coniferous trees, but also apply it to wood deciduous trees plot and ornamental drawings.

To make the texture of coniferous wood more expressive, it is enough to evenly scorch its surface. The softer summer areas of the annual layers are scorched much faster and easier than the dense autumn ones. The wood should be burned evenly, lightly touching the surface with the flame. Uneven movement of the torch can result in dark spots that make the job look sloppy. Don't try to get the final tone you have in mind right away. It must be achieved gradually. For example, to get a dark brown tan color, first scorch the wood to a light golden hue. After the second pass, the surface of the wood will become even darker. You need to do this until you get the desired tone. The scorch sticks to the wood quite firmly, but if desired, it can be coated with a clear varnish. Any method of applying varnish is suitable: by dipping, using a spray bottle or a swab.

If a flat metal object is placed on the wood surface to be fired in advance, then after firing a clear light silhouette will remain on it. On this basis, you can create interesting compositions by using them in decorative design interior of a school workshop, technical club premises, physics, mathematics and drawing classroom.

Quite complex compositions can be obtained in a matter of minutes, of course, if you have at hand required material. Place several metal pieces on a board or tablet to create a balanced composition. Then scorch open areas wood, achieving the intended tonality. After finishing firing, do not rush to remove parts from the surface of the wood. When in contact with the burner flame, the parts become very hot. Therefore, remove them after they have completely cooled down. A clear silhouette pattern will appear on the surface of the wood. To enhance the expressiveness of its individual parts, the silhouettes in some places can be worked on with an electric burning device.

A composition with a complex multi-tone pattern can be easily obtained by changing the position of flat parts directly during the burning process of wood, at its different stages. Silhouettes with a double contour are obtained by shifting the parts after the initial firing, and silhouettes of objects located one on top of the other are obtained by superimposing one part on an already obtained light silhouette from another part.

Along with finished parts, artists also use silhouette images as stencils, which are cut out from sheet metal(for example, letters, numbers, geometric shapes, images of humans, animals, etc.).

Obtaining texture relief on wood

Textural relief is especially appropriate in cases where it enhances the expressiveness of a chiseled or carved item or emphasizes some features of the depicted object. For example, in a conventionally decorative manner, it can convey the plumage of a bird, the scales of a fish, or the fur of an animal. A carved or chiseled sculpture must be made in such a way that the annual layers emphasize the shape as successfully as possible. Success largely depends on the correctly selected harvest, and above all on the location of the annual layers in it. You should not cut out small parts that can simply burn out during firing. The forms of sculpture, relief or any utilitarian thing should be generalized, simple and compact.
Place the sculpture or other wooden product on a brick and burn it evenly on all sides. At the first stage of firing, the loose part of the annual layers will be only slightly charred. Upon subsequent firing, the charred wood will become completely black. From time to time it will light up in selected places. Having extinguished the flame, continue to burn, but not in the place where the fire broke out, but nearby. Burning wood should be stopped after the top thin layer the product will be charred evenly in all areas.

It is advisable to remove burnt wood from the product at fresh air, somewhere in the corner of the yard or garden. Putting mittens on your hands, first remove the top charred layer with a steel carving brush. Then brush the wood, trying to guide it along the grain. The burnt out early part of the wood layers will be easily removed, and in its place relatively deep depressions will form. Late wood will appear in relief on the surface of the product.

Processing the product with a carving brush can be stopped at the stage when the early wood becomes golden ocher and the ridges of the textured relief retain a dark brown or almost black color. At this stage there will be no sharp contrast between the late and early wood of the annual growth layers, and the tree will give the impression of being old. If according to creative idea If it is necessary to achieve a contrast between the early and late parts of the annual layers, then the processing of wood with a carcass brush must be continued.

Wood harvesting and drying - processing features

The recipe, passed down from generation to generation, is relatively accessible to everyone, is intended for all hardwoods, and can be implemented without special costs or equipment.

1. Procurement of material

Tree cutting is usually carried out during the period of lowest sap content in the trunk - from the end of November to mid-February. For convenience, branches and twigs are cut off first, then the main trunk is felled. After this, the bark is removed (it is convenient to do this with a bayonet shovel; you must first cut off the end of the blade and, having sharpened the bevel, use it like a straight chisel - this method is more effective than traditional processing with a plow) and sawed into logs - round timber of the required sizes, depending on the author's ideas. At this stage, the workpiece needs to be marked somehow, for example, a notch can be made at the edge of the end of the butt side of the trunk. This fact should be recorded in a notebook for memory, so as not to get confused in the future.
2. Boiling of workpieces

The meaning of the next stage is that the method of boiling in boiling water accelerates the process of removing intracellular sap from the tree. For this purpose you will need a container; a regular linen boiler may be suitable (a woodworker I know made a pencil case from of stainless steel 2.5 meters long and installed electric heaters in it). In our case, the heating source can be a household stove, a Russian stove, or a fire. If the author has formed an idea - an image of a future work - then it is advisable to make a rough cut on the workpiece and you can still drill through hole in the center from end to end, followed by sealing with round plugs. This technique will speed up the rate of juice removal and reduce or eliminate the occurrence of cracks.

If the workpieces turn out to be longer than the size of the container itself, then by placing them vertically, you can turn them up and down during the digestion process. After placing the material in the container, pour water, bring to a boil and cook for 3 to 4 hours. To make the process more efficient, you can add table salt to the water (4–5 tablespoons per 1 liter of water), but if the work has to be done, then it is better to exclude salt, since it crystallizes and the incisors become dull very quickly. But if the wood is processed by milling and abrasives, then in this case, boiling with salt is advisable.

The liquid remaining in the container after cooking, for example from pear wood, can be used as a stain. Is there some more old way removal of intracellular fluid. The logs are placed in a reservoir with running water so that the butt part of the trunks is turned towards the flow. The reason for this arrangement lies in the structure and properties of the capillary-vascular system of trees.

3. Preliminary removal of liquid

The next stage is the preliminary removal of liquid from the wood. We will need an unheated, unlit room; if there is a window, then it should be properly closed - draped to prevent a possible ray of light from hitting the surface of the tree without creating conditions for cracks to occur. The room must have a concrete floor; a basement is best. As you know, concrete has the property of absorbing moisture. Now we take our pieces of wood, find the notches and marks and place each piece on the concrete with the butt side up and the top down. This technique is due to the creation of a more intensive removal of moisture from our workpieces. As is known, moisture rises forward movement passes through capillary vessels located in the structure of the tree trunk, from the roots to the top. Micro-chamber vessels turned “upside down” continue to perform their function effortlessly in a more comfortable mode and release liquid to the insatiable concrete. The efficiency thereby increases, and we speed up the process and eliminate the occurrence of cracks in the workpieces. The duration of this procedure takes 2–3 weeks (depending on the size of the material).

4. Ventilation–withering

The ends of the tree will need to be protected. This can be done by painting the surface of the ends oil paint, cover with paper. I prefer to cover with heated tar (it’s more thorough). We choose a place in the open air, more correctly on the north side of a building and under (from rain, snow and sun). We stack the pieces of wood on top of each other in a “well”.

Wood logs that are related to each other, from the same tree, placed in one pile, dry better. This process takes at least one month. The longer natural way withering, the more guarantees to avoid cracks in the future. After this, you can continue drying in a room with room (residential) mode, occasionally ventilating.

Consistent implementation of all preparatory stages and strict adherence to the conditions of this cycle guarantees time-shortened and high-quality drying of hardwood and fruit trees.
5. If you don’t have a moisture meter at hand

At a distance of 2.5–3 cm from the end of the board, a block is sawed across the grain, which is cut from the sides to 15 cm. The block is carefully weighed and then dried in an oven or oven at a temperature of approximately 100 degrees for 4–5 hours or on a radiator central heating within 48 hours

The dried block is weighed again. The resulting difference is divided by the dry weight of the wood and multiplied by 100 to give the percentage moisture content.

For example, it had a mass of 200 g, after drying - 150 g, the difference is 50 g. Dividing 50 by 150 and multiplying the result by 100, we get: (50/150) x 100 = 33% humidity.

To prevent the product from warping, the moisture content of the wood must correspond to the humidity of the surrounding atmosphere. Therefore, for interior crafts, in particular furniture, it is recommended to take wood with a moisture content of 6-12%, and for external works- even up to 25%.

What are the modern methods of drying wood?

Any homemaker knows that even well-treated raw wood becomes fluffy over time and is difficult to finish. Such wood is then difficult to sand, and the varnish and paint coatings on it crack and crumble. Products made from raw wood warp and become covered with deep cracks, which arise due to uneven drying of its layers (the fact is that during drying, the upper layers of lumber dry out and decrease in volume faster than the inner ones).

The minimum moisture content of the wood of a growing tree occurs in winter, and the maximum is in early spring. Of course, it is better to harvest wood, except aspen, at a time when there is almost no juice in it. In this case, it cracks and warps less. The more the wood dries out, the more numerous and deeper the cracks in it. Soft wood dries out less than hard wood. At the same time, soft wood dries faster and does not warp or crack as much as hard wood. According to the degree of drying, wood of various tree species is divided into three groups: low drying - spruce, willow, poplar, pine, cedar; medium-drying – oak, linden, aspen, elm; highly drying - larch, birch, maple, apple tree.

How to dry wood so that cracks do not form in it? This is a question of questions for every master. Any wood contains a certain percentage of moisture. And the latter should be removed so that the wood - this noble, warm, sunny material - does not warp. Wood should be harvested in late autumn or winter. At this time, there is a minimum of moisture in it, it cracks less, and the master can only dry it.

There are basically many drying methods. And depending on the conditions and circumstances, the master himself decides what he will do with this material. Please note that here we are not talking about industrial drying of wood, although some of its techniques are also suitable for drying “individually”.

Drying of wood in the forest directly on the root is carried out from spring to late summer. On the tree selected for felling, a wide ring of bark is removed around the trunk (closer to the roots). Moisture stops flowing into the crown of the tree and it gradually dries out. Moreover, such drying is facilitated by foliage, which intensively “pulls” moisture from the trunk. The dried tree is felled and sawn. Another, similar method is that, after cutting down a tree, two-thirds of the trunk is cleared of bark, without touching the branches with leaves and the upper part of the crown. The remaining foliage in two weeks, like powerful pump, pumps moisture out of the trunk, which would take more than one month to remove during normal drying in the open air. After two to three weeks, the trunk is sawn into ridges of the required length. The debarked and dried ridges are transported and dried under a canopy on the floor.

Small pieces of hard and soft can be processed at home. Raw wood is placed in a deep pan and filled to the top with salted water at the rate of 4-5 tablespoons of table salt per liter of water. The wood is simmered for two to three hours, then removed from the salt water and dried at room temperature.
Soaking wood in water reduces the appearance of cracks during subsequent drying. Logs were stored in water, which protected the wood of freshly cut trees from rotting during the season. Often, oak logs were immersed in the bottom of a stream or river (the water needed to be running). To prevent them from floating, a weight was tied to them. Apparently, wood makers were inspired by black bog oak to soak wood before drying, which they sometimes lifted from the bottom of forest rivers and streams. Having lain in water for dozens or even hundreds of years, the bog oak was hard as stone, and when dry it did not become covered with cracks.

in oil and drying oil on small pieces of hardwood not only prevents the appearance of cracks, but also enhances the decorative expressiveness of the material. Blanks for small carved items from apple, boxwood, pear and oak are boiled in natural drying oil, linseed, cotton, wood (olive) oil. During cooking, oil displaces moisture from the wood into the air, filling the intercellular spaces. The wood boiled in oil or drying oil is then dried at room temperature. Well-dried wood acquires additional strength and moisture resistance, and is perfectly sanded and polished.
Drying logs in a vertical position on dry ground is known in the southern regions of our country. For example, Uzbek carvers dried wood under a canopy in the open air.

When purchasing wood, we are usually interested in its moisture content. Nobody wants to buy raw lumber, since its use as a construction or ornamental material is justified only in rare cases (for example, for pouring concrete).

Therefore, logging and wood processing enterprises usually trade in wood that has already undergone the drying process.

What is wood moisture content

In production construction work and for the manufacture of wooden products, wood with a moisture content of no more than 23% is usually used.

In practice, several types of wood are distinguished depending on its moisture content:

wet – humidity more than 23%;
atmospheric-dry – humidity 18 – 23%;
air-dry (after artificial drying) – humidity 12 – 18%;
room-dry – humidity 8 – 12%.

The lower it is, the less susceptible it is to rotting. In addition, after drying, almost all properties of wood that are important for use are improved:

its strength increases;
deformability decreases;
, sanding, gluing, painting;
indicators such as electrical conductivity and heat capacity decrease, the calorific value increases;
The density of wood is directly related to its moisture content; the drier the wood, the lighter it is.

There is also the concept of equilibrium moisture content of wood. This means that at certain values of air humidity and temperature, the moisture content of wood remains unchanged and tends to a certain value.

If these parameters change, the wood will either release moisture into the surrounding atmosphere or absorb it until the humidity reaches a new certain value.

Thus, during the drying process of wood, its moisture content is deliberately reduced to equilibrium values, depending on where and how the lumber will be used.

Wood drying methods

All methods of excess moisture can be divided into the following types:

natural drying;

The first method is known to everyone. It consists of putting the lumber in a stack, where the rows are interspersed with spacers, putting a covering on top to protect it from precipitation, and leaving it to lie in the air. Due to constant ventilation of the stack, the wood loses moisture and dries out.

The second method is to dry the wood in special drying chambers., where you can regulate the air temperature and humidity. But this option is suitable for drying and is used mainly in woodworking enterprises.

What methods of drying wood can you use at home?

Even the ancient craftsmen knew how to perfectly dry wood to the desired condition. Many methods were used for this, some of which are still relevant today.

There is such an unpleasant property of wood as cracking when drying. However, not all types of wood are equally susceptible to cracking:

alder, linden, birch, poplar and aspen - dry almost without cracks;
larch, spruce, cedar, fir, pine - crack, but not too much;
beech, hornbeam, maple, ash, oak are subject to severe cracking.

This is a circumstance for drying each type of wood.

One of the well-known folk drying methods is drying the tree directly on the root. It is carried out as follows:

At a distance of about half a meter from the ground, the bark is removed in a ring along the entire circumference of the chosen trunk. The width of the ring is approximately 1 - 1.5 m. Reducing the width of the ring leads to an increase in drying time.
The removed bark stops the flow of moisture into the tree crown, while the foliage quickly consumes the remaining moisture in the trunk, thereby dehydrating it.
The readiness of the wood is determined by the degree of drying of the foliage.
When it is completely dry, the trunk can be cut down and used.

Drying the cut trunk:

The tree is cut down and, leaving a ring of bark on the trunk 0.7 - 1 m wide from the point of cutting, the rest of the trunk is left without bark. The crown is not touched.
The foliage remaining on the trunk quickly draws moisture from it, effectively drying out the wood.
After 2 - 3 weeks, the trunk can be sawed and folded under a canopy for final drying.

Drying is carried out in the same way as in enterprises: a flooring is built on a flat, dry area, on which lumber is stacked. The top row is laid with a slope and covered from precipitation.

To protect the ends of the material from rotting, they are covered with lime, treated with a solution of table salt or coated with liquid glue.

This method allows you to get rid of 75% of the moisture in the wood, but is very slow:

coniferous and soft hardwoods dry out within 1 – 1.5 years;
hardwoods – more than 2 years.

Drying wood in a closed, ventilated area. To do this, you can use a spacious barn or a fairly high attic. Here there is a stack of wood laid on pads than on the street. It is only necessary to ensure constant ventilation of the room.

Drying lumber on a cement floor. This method is sometimes used to dry small volumes of lumber. It is laid out in one row on a cement floor and the boards are turned over from time to time. The method is based on the ability of cement to draw moisture from other materials upon contact.

Drying small wooden blanks and details using newspapers:

the workpiece is tightly wrapped in dry newspaper and placed in a plastic bag, which is tightly wrapped.
The bag with the workpiece is placed in a warm place.
When the newspaper becomes damp, it is replaced with dry one and the process is repeated until the workpiece reaches the required humidity.

This process usually lasts about 3 – 4 weeks. As the wood dries, the newspapers have to be changed less and less often. To speed up the process, the workpiece can be wrapped in a thicker layer of paper, but here, drying too quickly can lead to cracks.

Drying workpieces using sawdust or straw: the workpieces are covered with a thick layer of sawdust or dry straw and placed under a canopy. Sawdust and straw take moisture from the wood, but there is no need to change them, they quickly dry out on their own.

Drying by steaming and boiling wood.

These are more complex methods, but they can be successfully used at home.
The steaming method is used to replace the moisture contained inside the wood with vegetable oil. To do this, the workpiece is placed in a container with any vegetable oil and heat over low heat for 6-7 hours.

The steaming time depends on the size and thickness of the workpiece. In former times, wood intended for making wooden utensils was processed in this way. And the dishes turned out to be very durable, without cracks.

The digestion method involves keeping the workpiece for a long time in a boiling salt solution (2 tablespoons of salt per 1 liter of water). Salt expels cell sap from wood, replacing it. The saline solution itself is expelled from the wood much faster than water and without “serious consequences.”

After boiling for 8 - 10 hours, the workpiece is removed, tied with a rag and placed in a dry place for 2 weeks. When using boiling, you can simultaneously change the color of the wood. To do this, pine sawdust is mixed into the saline solution. If the workpiece has big size, then after drying in air, the digestion is repeated, then the workpiece is dried again. All this time the harness is not removed from her.

If the products were made from damp wood, they can be dried using dry, clean river sand. To do this, the workpiece is placed in a container of suitable size, sprinkled with sand on all sides and placed in the oven.

We looked at the best ways to dry wood at home. They all require time and patience. So if you urgently need a dry blank or several boards, then it would be more advisable to purchase blanks of the required moisture content.

If you are a home craftsman and you have nowhere to rush, traditional methods drying will be just right. After all, they almost 100% guarantee proper drying of the wood, in which the risk of cracks is minimal.