Drying wood is an important stage in preparing lumber for work, as a result of which excess moisture is removed from the wood by evaporation. Why is this done? Dry wood is characterized by high strength. It shrinks much less, sticks easily, is not subject to decay and cracking. Finished products are easy to decorate and are distinguished by enviable reliability. Thus, the process of drying wood is mandatory if you want to get products of impeccable quality..
The types of wood drying are quite varied. But they all pursue the same goal – to obtain a reliable building material with improved physical properties..
It is noteworthy that the evaporation technique was first used in ancient times..
A piece of wood was placed in a tank of water (70 degrees), sprinkled with sawdust on top and left to steam. As a result, the wood not only did not crack, but also acquired a dense, flexible structure..
Another method was also used – waxing. The workpieces were dipped in liquid paraffin (40 degrees) and left for several hours. The tree obtained in this way did not warp, it acquired a beautiful dark shade. Waxing was most often used in the manufacture of tableware. Wooden cups and spoons could only be painted with simple patterns and varnished. It is interesting that the products turned out to be so durable that they did not crack under any circumstances..
It is not so easy to get good material in a short period of time. A way out of the situation can be a quick drying of the wood. If the tree is a churak (ridge) in the bark, then it is better not to remove the bark, but to cut it across the trunk. You can leave a bark 10 cm wide only at the edges of the block.
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Alder, birch, aspen, linden (even completely peeled) dry without cracks with moderate drying. However, the ends of the logs should be coated with oil or resin..
Drying lumber naturally is necessary in a well-ventilated, dry area. When dried in the sun, the outer surface will heat up and the inner surface will remain damp, resulting in imperfections. The workpieces are stacked on supports with a height of at least 60 cm. There should be ventilated gaps between them..
There is an opinion that boards installed on the edges dry out twice as fast. However, keep in mind that they will also warp more. The technology of drying wood at the ends also gives cracks – you will have to cut the beams. This is why the workpieces must be longer than the required length..
Drying time for wood in a natural way is 2-3 years. This is one of the disadvantages of the method, because it is not always possible to wait for that amount of time. The advantages include the simplicity of the procedure and the absence of large financial costs.
If the cost of drying wood does not matter much, because an excellent result is an end in itself, it is worth paying attention to other options.
Chamber drying is highly efficient, it allows you to monitor the progress of the process and obtain the material with the strictly necessary moisture content. It is carried out in an industrial environment. Containers with a board are driven into drying plants, where, under the influence of a gaseous medium, the liquid is evaporated. Timber drying modes can be changed at your discretion.
PAP cameras are metal devices with aerodynamic heating. During the drying process, it is necessary to add low pressure steam to the chamber. The operation process is not difficult. But such drying of wood has a significant price, which is explained by the high consumption of electricity..
This method is based on the use of centrifugal force. Stacked lumber is installed on a special platform inside the heated room. Centrifugal force promotes the movement of moisture to the ends and outer surfaces of the beams.
The intense movement of hot air creates favorable conditions for uniform drying of lumber in the shortest possible time. Special stoves or lamps act as heat sources. The flux of infrared radiation quickly spreads and penetrates to a depth of 12 mm. This means that coniferous wood with a thickness of up to 25 mm can be dried in a few minutes, which is several times faster than chamber drying..
Contact, or conductive, drying is realized by transferring heat from a heated surface. The method is especially effective when working with thin materials such as plywood or veneer. The sheets are clamped with a press between two heated plates. Heat is transferred to wood through close contact, which explains the name of the method.
One of the most common ways to get dry wood. Does not require additional energy resources and can be used at home.
The productivity of atmospheric drying of wood at home depends on several factors. In particular, from the humidity of the ambient air, the season, the temperature of the environment. It is also worth noting that warehouse equipment for drying wood will require a lot of free space and certain conditions..
- you can dry wood under a canopy or in a shed, but always with intensive through ventilation;
- boards are stacked in several rows at small intervals;
- to reduce the risk of warping, you can put something heavy on top.
In dry weather, the atmospheric drying method allows to obtain wood with a moisture content of 12-48%. If necessary, it can be dried to a lower percentage in a well-heated room..
Used as an additional measure before impregnation with oil antiseptics. Aqueous solutions of mineral salts or hydrophobic substances (molten metals, paraffin, sulfur) act as a liquid agent.
The duration of the process is limited by the intensity of the redistribution of heat in the dried lumber and the capacity of the heat exchanger in the drying chamber. The wood is immersed in liquid and brought to a boil. The constancy of the temperature regime is maintained until free moisture is completely removed. Drying time – 3-20 hours.
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On average, the duration of natural drying is from several weeks to several months. Artificial – from several hours to several days.
Of course, this is not a complete list of wood drying methods. There is also radiation, induction drying, drying in an electric field of high frequency current or with the help of refrigeration equipment..
Not everyone has the opportunity to use professional drying installations, but you should not despair. You can also dry wood at home..
- deciding on a place. The drying area must be in an open area. This can be the middle of a vegetable garden or a flat roof of a low structure. Cover the surface with roofing material and sprinkle with sawdust;
- we lay the material. It is important to consider the direction of the wind – the stack is stacked across, not along the wind flow. Stack width – 1.2 meters (maximum). Optimal is 0.8. Height can be any, but not less than 0.5 m;
- arrangement of supports. The goal is to lift the bottom boards. The most reliable design is a well made of timber with a section of 50×50 mm. Lay out 2 wells with a height of 0.7 m, lay a support gasket with a section of 60×80 mm. The recommended distance between the supports is 1.5 m. It is important that the surfaces of the upper gaskets are in a strictly horizontal plane;
- pile retraction. Gaskets are additionally placed on the upper layer of the blanks, after which the ends of the lower and upper boards are pulled together with a rubber band cut from the car camera. Belt width – 40 mm;
- wood protection. The boards should be protected from atmospheric precipitation. However, it is not necessary to completely cover the stack. Place a few dry poles on top of the spacers (along the length of the stack). Lay sheets of roofing iron on the handrail until a 15 mm canopy is formed. Lay the still dry poles on top, and so that they are not blown away by the wind, pull them together with a rope. An air gap of 8 cm should form.
That’s all. The homemade dryer is ready. Now you know how to avoid wood cracking and significantly improve its performance. Let the products from your own hand-dried wood be not only beautiful, but also durable!