Wood of coniferous trees bark and pith sapwood and heart wood the. A process and apparatus for accelerated drying of green lumber employs high voltage dielectric heating at subatmospheric pressure to effect a rapid removal of moisture from the wood without splitting, checking, case hardening, honeycombing or similar damage to the wood structure. An introduction to the seasoning of timber discusses the applied technology of wood preservation. By reducing moisture content, the strength, elasticity and durability properties are developed. In air seasoning, the boards are stacked and divided by narrow pieces of wood called stickers so that the air can circulate freely about each board. The purpose of seasoning is to reduce the moisture content in the wood to a level appropriate to the use of the articles made from the wood.
The following pdf lecture is uploaded in moyleparkwoodwork. Finally, most strength properties increase as timber dries and, although the increases may not in themselves justify the expense of seasoning, they are of more than academic significance. Peck,1 technologist forest products laboratory, 2 forest service introduction wood bending is an ancient craft that is of key importance in many industries today, especially in those that manufacture furni ture, boats and ships, agricultural implements, tool handles, and sporting goods. Wood hardly seasons at all in log form, and certainly not in a year. Mar 26, 2016 seasoning of logs the process of seasoning starts from the time the tree is felled or, sometimes in the standing trees itself, as in the case of girdled trees. Floor rectified 316 when multiple sizes are installed in a modular pattern, andor when installing tile with a length 15 or greater in a staggered brickjoint pattern. When the drying is done in a kiln, the product is known as kilndried timber or lumber, whereas air drying is the more traditional method. In other words, chemical seasoning of wood enables the timber to dry first from inside. It is expressed as a percentage of the dry weight of the timber like 15% or 25% moisture two methods are used to determine the moisture content of wood the oven drying method. Special methods of seasoning wood vapor drying agriculture room forest products laboratory f forest service u.
Water seasoning takes less time than air seasoning, but the strength of wood is reduced. Attack by wood destroymg fungi, 1fl particular, is prevented. More than half the weight of freshly cut timber consists of moisture or sap. This is necessary for reducing the unnecessary weight of timber, for effecting an increase in its strength, to improve its workability, to reduce the possibility of development of shrinkage defects and to ensure durability or long life of timber the moisture content of standing trees may be as. Seasoning is the reduction of moisture content of timber to that of thesurrounding air sydney area approx. Wood is essentially a mass of tiny long tubes, or cell cavities, that run the length of the tree. Seasoning also prepares timber for various finishing processes, such as painting and polishing, and it is an essential prerequisite if good penetration of wood preservatives is sought. The process has undergone a number of refinements over the years that have made it more efficient and reduced the quantity of wood that was damaged by drying too quickly. Seasoning of wood by joseph bernard wagner free ebook. Keeping especially in mind the arrangement and direction of the fibres of wood, it is clear at once why knots and crossgrain interfere with the strength of timber.
This method of seasoning is highly suitable for seasoning green wood full of sap. However by water seasoning, the timber is less liable to warp, crack and distort. When wood dealers split these seasoned logs, the product is almost always too wet to responsibly burn. The problem is, most wood dealers do these same thing since it means a lot less wood handling and its much easier to inventory. Practically all wood before being put to use is either seasoned in the air or dried in a kiln. Tips for properly seasoning firewood mother earth news. Timber is seasoned to dry out the timber to bring it to a usable and workable condition. Seasoning is the process of drying timber to remove the bound moisture contained in walls of the wood cells to produce seasoned timber.
Seasoning of timber lumber wood free 30day trial scribd. May 11, 2007 seasoning is the process of drying timber to remove the bound moisture contained in walls of wood cells, producing a new product called seasoned timber. We have tried, in preparing this copy, to make the content accessible to the widest possible audience but in some cases we. Followings are the reasons to perform timber seasoning. Seasoning is the process of removing the moisture content from wood to minimize structural problems when used in construction or to provide less smoke and more uniform combustion when used as firewood. Pdf the process of inducing evaporation of the moisture contained in wood. Seasoning of timber download ebook pdf, epub, tuebl, mobi. When wood is used as a construction material, whether as. Wood drying also seasoning lumber or wood seasoning reduces the moisture content of wood before its use. The seasoning and kilndrying of wood is such an im portant process in the. Unseasoned green wood is subject to attack by fungi and insects, and it also shrinks as it dries. Its saturated moisture content could then be said to be 1 x 100 per cent or 400 per cent. A wellseasoned timber has 15% moisture content in it. Note that, these pdf files are not a property of and if violets any issue please feel free to let us know.
To make it easy for the learners, we have embedded these pdf files together. The book is comprised of 10 chapters that cover both methods and concerns of. This prevents changes in the dimensions and shape of the articles, eliminates wood rot. By seasoning of timber, it is understood that the controlled reduction of moisture from the wood. It is definitely an advantage as it prevents the risk of cracking of outer shell. This document has been scanned from hardcopy archives for research and study purposes. Seasoning of timber is the process by which moisture content in the timber is reduced to required level. The traditional method of seasoning timber was to stack it in air and let the heat of the atmosphere and the natural air movement around the stacked timber remove the moisture. Different ways of seasoning wood home guides sf gate. This document has been scanned from hardcopy archives for. Fungi and termites cannot grow in wood with a moisture content of less than 20 percent. The owner of a small quantity of green lumber or logs is often confronted with seasoning it to a state of dryness suitable for use in furniture, wood carving, or. Methods of natural air seasoning of wood timber how to.
Pdf harvesting and seasoning wood for building purposes. Bending solid wood to form forest products laboratory. Finally, most strength properties increase as timber dries and, although the increases may not in themselves justify the expense of seasoning, they are of. It is due to the structural peculiarities that honeycombing occurs in rapid seasoning, that checks or cracks extend radially and follow pith rays, that tangent or bastard cut. The different ways that seasoning in wood can be achieved. When air is absorbing moisture less rapidly, as a result of its relative humidity. Whether artificially seasoned or left to dry naturally in place. This is a pdf file of an unedited manuscript that has been accepted for publication. It is due to the structural peculiarities that honeycombing occurs in rapid seasoning, that checks or cracks extend radially and follow pith rays, that tangent or bastard cut stock shrinks and warps more than that which is. Effect of seasoning with practically all species, nails driven into green wood and pulled before any seasoning takes place offer about the same withdrawal resistance as nails driven into seasoned wood and pulled soon after driving. Seasoning is the process of removing the moisture content from wood to minimize structural problems when used in construction or to provide less smoke and more. Moisture exists both as free water in these cavities. Because it does not shrink evenly in all directions, it is likely to split and warp.
There are two methods of seasoning of timber which are explained below. This prevents changes in the dimensions and shape of the articles, eliminates wood rot, increases the strength of the wood, reduces the weight of the articles, strengthens glued joints, and improves the. Seasoning of timber and drying of wood types and methods. In the drying of a block of wood the moisture at and close to its exposed faces evaporates first, and after a time, the free water in a thin layer at the surface having. The shrinkage that accompanies seasoning is completed before the wood is put to use.
Seasoning, in lumbering, drying lumber to prepare it for use. The conversion and seasoning of wood is an excellent book for the farmer, woodworker, or any craftsman involved in the conversion or seasoning of wood. Hartley free and bound moisture expressed as a formula. Weight of wood substance moisture content consider an ordinary sponge.
Seasoning of timber is done to fulfill some specific requirement. Commercial methods of piling boards, planks, and other shapes of wood for air seasoning. Effect of seasoning of different woods on resistance. The initial seasoning of timber in the log is just as important as the ultimate seasoning of sawn timber. Seasoning can be achieved in a number of ways, but all methods aim to remove water at a uniform rate to prevent damage to the wood during drying seasoning degrade. The actual drying of wood in log form is extremely slow, and the amount of. There are two main ways of seasoning timber, natural air and artificial kiln drying. Tennessee is fortunate to have an abundant supply of tree species with dense wood that potentially makes good firewood. The wood surface remains moist while moisture from the interior goes on diffusing to the exterior. Seasoning can be achieved in a number of ways, but the aim is to remove water at a uniform rate through the piece to prevent damage to the wood during drying seasoning degrade. This could weight only 100 g when dry, but when it is saturated with water it could weight 500 g. Harvesting and seasoning wood for building purposes.
Seasoning is the process of removing the moisture content from wood to minimize structural problems when used in construction or to provide less smoke and more uniform combustion when used as. This is such an important stage in the drying that it is given a special name, and the term is. The timber is stacked with wide spaces between each piece horizontally, and with strips of wood between each layer ensuring that there is a vertical separation too. Seasoning of timber or drying of wood wood drying also seasoning lumber or wood seasoning reduces the moisture content of wood before its use. Wood seasoning article about wood seasoning by the free. Moisture content mc of wood moisture content mc is the term used to describe the amount of moisture in the wood.
Air can then circulate around and through the stack, to slowly remove moisture. In other words it holds four times its own weight in water. W179 wood products information moisture content of. Methods of natural air seasoning of wood timber how to do. Before the timber can be used a large part of the moisture must be removed. W179 wood products information wood products test results firewood and moisture content a wood fire is a pleasant, inexpensive and environmentally friendly way to heat a home. Seasoning is the process of removing the moisture content from wood to minimize structural problems when used in. Drying reduces the likelihood of insect infestations, mold, stain and decay during storage and use. To make a correct percentage of shrinking of woods. The basic principle is to stack the timber so that plenty of air can circulate around each piece.72 1346 603 950 512 1342 202 768 125 727 74 1172 727 460 1267 95 755 938 876 1501 1365 783 1131 1285 412 377 221 122 1165 187 897 826 1333 1316 944 488 822 104 486 432