Wood drying is an obligatory stage of processing lumber. Excess moisture is removed by evaporation, and natural material reaches the required condition before use. Joiners know that without this technological process, a tree will not be durable. It will warp, crack and rot, and these are serious problems. If you want to get the effect of working with wood, you need to know how to properly dry wood, and in what ways to do it.
Ways
There are several methods that allow you to dry harvested wood with your own hands, and all of them are aimed at obtaining high-quality building materials with the necessary physical parameters. Regardless of which method is chosen, before drying the wood, it is carefully inspected for defects.
Grandfather secrets
Evaporation technology came to us from the past, and it consists in immersing the boards in a container filled with hot water (about 70 ˚C), on top of which sawdust is poured. After such steaming, the material did not crack, and the tree itself additionally received elasticity and a dense structure. A known method of waxing, when for several hours the workpiece was dipped in liquid paraffin heated to 40 ° C. After this procedure, the board did not warp, additionally acquired a beautiful dark tone.
The process of drying wood by waxing was used in the manufacture of dishes. The master had to decorate the cups and bowls with patterns, and then cover them with a protective layer of varnish on top. The finished products were so durable that even with a temperature difference they retained their original appearance, and not a single crack could spoil the fruits of the master.
Natural drying method
Natural wood drying demonstrates how to dry workpieces at room temperature without using expensive equipment. If we are dealing with a ridge covered with bark, then the top coating is not removed, and notches are made across it across the trunk. You can leave strips of bark with a thickness of not more than 10 cm along the edges of the ridge.
Naturally drying lumber ensures that there are no cracks in hardwood, such as Birch, Linden or aspenHowever, the ends of the logs are still better to tarry or cover with oil.
The room in which the wood is dried should be dry and well ventilated. Make sure that direct sunlight does not fall on the log, otherwise its surface will excessively overheat from the outside, and the inside will retain moisture, making the material very likely to crack. The correct way to dry lumber involves stacking it on a stand. The distance must be at least 60 cm from the ground, while ventilated gaps must be provided between the workpieces.
To the question whether it is possible to dry quality boards installed on the edges, the answer is categorical - no. This is a fairly quick home drying method, but with it, timber is often warped and cracked. The same applies to the drying of wood at the ends, after which the timber has to be cut. This must be taken into account when planning the required length of workpieces. Full drying of oak or any other kind of wood in this way lasts at least two to three years, and this is a serious drawback, because the master does not always have time. The indisputable advantages of natural drying include its simplicity and lack of cash costs. If you are not satisfied with the timing of the manipulation, and the timber needs to be dried quickly, albeit with additional costs, you can use the drying chamber.
Chamber drying
Chamber drying of lumber is an advanced modern method that allows you to get an excellent result quickly. This can be done if you are ready for financial investments. The advantage of accelerated drying of wood, which is carried out in an industrial environment, is that you can achieve the desired moisture parameters without problems. The chamber process is carried out as follows: carts with lumber are fed to a drying unit, where, under the influence of a gaseous medium, liquid is removed from the wood structure. Drying mode may vary depending on the requirements and at the discretion of the master.
PAP chambers are metal drying chambers inside which special equipment is installed that provides aerodynamic heating. According to technology, steam is regularly pumped into the chamber under low pressure. Despite the simplicity of this method, you cannot call it cheap, due to the high cost of electricity, which significantly increases the cost of the processed material.
Rotational method
There is another effective method in which it is possible to dry the timber through the action of centrifugal force. Boards stacked on the platform in stacks are placed inside the heated room. Centrifugal force provides uniform movement of moisture from the inside of the log to its ends and external surfaces.
Intensively moving hot air allows you to quickly dry lumber to the desired condition, and lamps or plates designed for such purposes act as heat sources. Rotational or infrared drying, in which radiation penetrates the wood to a depth of 12 cm, can take only a few minutes, than this method noticeably wins the chamber, and atmospheric wood drying, which lasts more than one year, remains far behind in terms of efficiency.
Conductive method
If you need to remove moisture from a thin material, such as plywood or veneer, it is better to prefer conductive (contact) drying, in which it is customary to use a press. Sheets are clamped between plates warmed up to a certain temperature, which are in direct contact with the processed material - hence the name of the method. Contact, or vacuum drying of wood, eliminates the need for fans. This saves energy. No humidification system and numerous thermometers needed. As auxiliary equipment in vacuum installations, humidity sensors are used, which are controlled from the outside. The absence of aggressive temperatures and a mild process of evaporation of moisture protects the dried wood from deformation.
Atmospheric method
Atmospheric drying is a good example of how to dry boards at home without additional energy.
The effectiveness of atmospheric drying directly depends on a number of factors, such as climatic conditions, season, or temperature and humidity. To install warehouse equipment you will need a place, as well as following simple rules:
- the dryer in the shed or under the canopy should be intensively ventilated;
- wooden material is stored in several rows with mandatory technological gaps;
- so that the tree does not lead and warp, it is usually pressed from above with something heavy.
In dry weather, atmospheric drying will allow to reach 12–48% humidity, and to obtain more significant indicators, the room method in a heated room can be applied.
Drying in a liquid medium
Quick drying in liquids is an additional measure before processing the workpieces with antiseptic agents. As an active agent, water-salt solutions or hydrophobic compounds (sulfur, paraffin, liquid metals) can be used here.
The duration may depend on the capacity of the heat exchanger installed in the drying chamber, and the intensity of heat redistribution inside the fibers, depending on the type of wood. The board is immersed in a liquid and brought to a boil, maintaining the optimum temperature until free moisture is removed, which takes an average of 3 to 20 hours.
In addition to these methods, there are a number of other methods (radiation, induction, microwave, refrigeration), but none of them is possible at home due to the specifics of the equipment and its high cost. As for the drying time, with accelerated artificial methods, the timber dries only a couple of hours. Properly dried wood will last more than one decade in the form of a finished product, while a workpiece with excessive moisture will quickly become unusable, so you cannot ignore such an important technological process.