Seasoning of lumber pdf

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. Although quoted from a later edition, editions of the book printed in the 1860s featured text identical to this. A wellseasoned timber has 15% moisture content in it. 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. Cmt seasoning and deffects of lumber free download as powerpoint presentation. Oct 25, 2017 the term seasoning carries the meaning that the wood had been exposed to one or more seasons of weather. Us2296546a method of artificially seasoning lumber. If reasonable care is exercised, however, wellseasoned lumber can be obtained by this method. Larger forests tend to be commercially owned operations. A treatise on the natural and artificial processes employed in the preparation of lumber for manufacture, with detailed explanations of its uses, characteristics and properties. These standards are reflected in the grade stamp by the following abbreviations. When the drying is done in a kiln, the product is known as kilndried timber or lumber.

In kiln seasoning, timber is dried for specific periods and under very controlled conditions of temperature and humidity in specially designed kilns. Seasoning of timber and drying of wood types and methods. Presents recommendations based on recent research and industry practice for drying eastern hardwood lumber, including dimension items. Length of drying time is also greatly reduced and is predictable so that dry lumber inventories can often be reduced. A guide to principles and practice w h brown, william brown on. The compartment process is conducted in a building where the lumber is stacked in a manner that allo2ws the air to circulate.

I dont believe there is any wood product that the consumer is more familiar with than furniture. Tunnel type kilns can also be used for this purpose. This method also provides advantages such as high speed and high quality and is well suited for seasoning lumber, blocks, veneer, chips, paper and woodbased composite materials. Grade designationidentifies the grade of the lumber. Jun 14, 2018 wood drying also seasoning lumber or wood seasoning reduces the moisture content of wood before its use. The lumber may be protected from the rain and sunlight with a small roof on each pile of lumber or by sheds. Seasoning is the reduction of moisture content of timber to that of thesurrounding air sydney area approx. By seasoning, generally, the moisture is reduced to about 15% where new cut woods bear about 50%. Seasoning definition, salt or an herb, spice, or the like, for heightening or improving the flavor of food. Accent is on comparing methods for energysaving management decisions, but practical guidance is also given to wood drying personnel. Kiln seasoning kiln seasoning of wood is a commercial process that employs two processes, progressive and compartmentalization. Seasoning is the process of removing the moisture content from wood to minimize structural problems when used in. Attack by wood destroymg fungi, 1fl particular, is prevented.

Air drying air drying is the exposure of lumber to outside environmental conditions, with no artificial. 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. When air is absorbing moisture less rapidly, as a result of its relative humidity increas ing, differences in moisture content of. Google has not performed a legal analysis and makes no.

Sticker placement stickers, small uniformsized boards, allow spaces for air to move across the lumber surfaces. Different types of defects occur in timber at these various stages. Scope and object of the bulletin the purpose of this bulletin is to present briefly the general prin ciples of kiln drying and then to show the application of these prin ciples to the kiln drying of southern yellow pine lumber. Water seasoning is the process in which timber is immersed in water flow which helps to remove the sap present in the. A few of the more important reasons rielz, 1957 are. Condition of seasoningindicates the moisture content of the board at the time it. Lumbermen taking advantage of this property have been known to sprinkle salt on checked lumber in order to attract moisture, dampen the surface of the lumber, and thus close the checks. In a first step, the lumber is piled up into a pressure vessel for seasoning. Pdf 4 wood and wood products introduction classification. The basic principle is to stack the timber so that plenty of air can circulate around each piece. Mill identificationallows wwpa to identify which mill produced a piece of lumber.

An introduction to the seasoning of timber discusses the applied technology of wood preservation. Before reaching this final stage, timber comes across many critical stages like growing without defects, cutting at the right time, seasoning, converting and using. The stack is slanted to facilitate drainage of rain. You can also read the full text online using our ereader. Different ways of seasoning wood home guides sf gate. Artificial methods of seasoning of wood air seasoning. In other words seasoning of timber means getting rid of the sap and. Purchase an introduction to the seasoning of timber 1st edition. Before the timber can be used a large part of the moisture must be removed. Among the hygroscopic chemicals which have been suggested for use in the chemical. The conversion and seasoning of wood covers the many aspects of timber conversion, detailing the most advantageous methods of cutting to produce the best yield and to preserve the best features of the wood. Lumber piled in this fashion may lead to warp, check, stain and decay. When freshly cut lumber is seasoned it tends to undergo a surface drying and shrinking which results in splitting, warping, and checking.

Authority us united states prior art keywords steam lumber pressure temperature wood prior art date 19410315 legal status the legal status is an assumption and is not a legal conclusion. Removal of moisture from timber so as to be in equilibrium with moisture in surrounding atmospheric condition, where timber is likely to be used is called as seasoning of timber. Lumber by gene wengert from the university of wisconsin, drying eastern hardwood lumber, usda agricultural handbook no. Natural seasoning may be water seasoning or air seasoning. 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. Trees gives us the timber which is converted into required form and finally used. Pdf the process of inducing evaporation of the moisture contained in wood. Kiln seasoningkiln seasoning kiln drying of lumber is perhaps the most effective and economical method available drying rates in a kiln can be carefully controlled and defect losses reduced to a minimum.

Species identificationindicates the species or group of species of tree. By seasoning of timber, it is understood that the controlled reduction of moisture from the wood. Framing lumber moisture content and seasoning in unseasoned green dimension lumber and heavy timbers moisture content standards for framing lumber the north american softwood lumber industry has three moisture content standards for framing lumber. The term seasoning carries the meaning that the wood had been exposed to one or more seasons of weather. 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. The moisture in the timber which is to be dried out during seasoning may be divided into. In end use, as the unseasoned lumber dries naturally and adapts to its environment, it becomes approximately the same size as lumber that was surfaced at a lower moisture content and manufactured to the size standards for dry lumber. This is such an important stage in the drying that it is given a special name, and the term is. 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.

Reduction of moisture content along with improving some qualities before the use of woods is called seasoning of timber. Anonymous 1959 airseasoning of lumber speeded by new system. This document has been scanned from hardcopy archives for. Seasoning is the process of drying moisture from timber. Types of defects in timber as a construction material. Methods of natural air seasoning of wood timber how to. Whether artificially seasoned or left to dry naturally in place. Dec 23, 2015 removal of moisture from timber so as to be in equilibrium with moisture in surrounding atmospheric condition, where timber is likely to be used is called as seasoning of timber. Seasoning is the process of drying lumber either in a kiln or air drying to an appropriate level of moisture for woodworking and other commercial uses. Hartley free and bound moisture expressed as a formula. Methods of natural air seasoning of wood timber how to do.

Covers different methods of cutting and drying timber. This document has been scanned from hardcopy archives for research and study purposes. Hardwood forests are regenerated by natural cycle or by new plantings. An introduction to the seasoning of timber 1st edition. Water is just as essential to the life of a tree as it is for all living matter. Among the other methods of seasoning of timber and wood, the chemical seasoning and electric seasoning are of some importance. The book is comprised of 10 chapters that cover both methods and concerns of seasoning timber. Together with the various minerals, it enters through the roots of the tree and is carried in the sapwood theouter woody part to the leaves. In lumber manufacture this means the highest possible yield of lumber, both in quality and quantity. In other words, the timber or lumber is air dried for about one year.

To improve structural performancea prerequisite to the allocation of seasoned timber strength sd and joint groups jd is that the average moisture content in the piece be no more than 15%. This is a great read to anyone wishing to convert timber into lumber. Harvesting and seasoning wood for building purposes. 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. This is done to enable any contained water within the vessels capillary tubes and cell cavities to evaporate.

Timber is seasoned to dry out the timber to bring it to a usable and workable condition. Seasoning lumber in the united states, most hardwood comes from privately owned forests, and most privately owned forests. 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 there are two main reasons for drying wood. This book is available for free download in a number of formats including epub, pdf, azw, mobi and more. Application to air seasoning of the general principles of drying wood. Scribners enlarged lumber and log book although quoted from a later edition. In a product where pieces of wood are fitted and fastened together and then used daily in the home, the value of.

Wood drying also seasoning lumber or wood seasoning reduces the moisture content of wood before its use. Method of artificially seasoning lumber download pdf info publication number us2296546a. Seasoning lumber various factors must be considered if good results are to be obtained by seasoning. Drying the moisture out of wood enhances its properties to such an extent that the resulting timber is given the special name seasoned rather than dried. Crossett lumber co priority date the priority date is an assumption and is not a legal conclusion. Air can then circulate around and through the stack, to slowly remove moisture. Seasoning of timber is the process by which moisture content in the timber is. Pergamon series of monographs on furniture and timber, volume 1. Yn developing schedules for dry lumber, z variablesdrybulb temperature and ccadn.

Wood seasoning article about wood seasoning by the free. Overhanging lumber is susceptible to breakage and warping. The utilization of lowgrade lumber is one of the key problems in the practice of forestry. Seasoning of lumber for furniture production by harold d.

Shorter lengths of lumber may also be placed within the stack if both front and rear ends of the stack are kept flush. Practically all wood before being put to use is either seasoned in the air or dried in a kiln. Scribners enlarged lumber and log book rochester, ny. Knots sound, firm, encased, and pith knots, if tight and well spaced, are permitted in. 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.

Woodworking when wood is used as a construction material, whether as a structural support in a building. Mar 26, 2016 air seasoning, air drying, open air seasoning or natural seasoning, as the process is known is therefore the drying of wood, under ordinary atmospheric conditions to a certain moisture content, which is in equilibrium with the temperature and humidity of the atmosphere in which it is seasoned. If you mean lumber or boards, the lumber needs to be stacked in a way. Among these are the size of the lumber to be dried, the use. The simplest method of seasoning lumber is openair seasoning, in which the lumber is stacked in the open air or under canopies for a period of two or three weeks to several months. Oct 10, 2016 kiln seasoningkiln seasoning kiln drying of lumber is perhaps the most effective and economical method available drying rates in a kiln can be carefully controlled and defect losses reduced to a minimum. This process may take from a few months to several. A three step process to season lumber to reduce cracks in the lumber and reduce warping of the lumber. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.

The present invention is concerned with an improvement in the chemical seasoning of wood and is particularly directed to a new process and product adapted to be employed in the treatment of unseasoned lumber. Seasoning of timber is done to fulfill some specific requirement. Seasoning of wood by joseph bernard wagner free ebook. Seasoning of timber or drying of wood wood drying also seasoning lumber or wood seasoning reduces the moisture content of wood before its use. Seasoning is defined as the removal of moisture that is present in the timber in its green state. That common salt has the property of attracting moisture when stored in a damp place is common knowledge. Air drying air drying is the exposure of lumber to outside environmental conditions, with no artificial heating, control of velocity, or control of humidity. The national grading rule applies to all species of softwood lumber1 which are covered by grading rules developed and approved under ps 20. One of the purposes of this joint meeting is to emphasize the importance. Hall, dry kiln foreman, grays harbor chair manufacturing co. Cmt seasoning and deffects of lumber lumber building. Fibre saturation point as the free moisture leaves the cell cavity, it will eventually become empty, leaving the cell wall still saturated.