Woodworking

I. Introduction

Woodworking, the forming or shaping of wood to create, restore, or repair useful or decorative objects. Carpentry, joinery, and cabinetmaking are specialized woodworking crafts, providing a range of products from wooden structures and furniture to wooden toys.

II. Historical Background

The unique characteristics of wood have made it a basic material for housing, furniture, tools, vehicles, and a multitude of other products throughout history. Woodworking, in fact, was one of humankind's first skills. From the wood clubs and spears at the start of civilization, the use of wood was extended to dugout canoes, farm plows, and simple three-legged stools, to the ornate cabinetry and intricate structures of modern times.

Various woods were observed to have their own unique textures, hues, and fragrances and were used accordingly. Tough and durable oaks, for example, were fashioned into ship's timbers, bridge girders, staves for barrels, fence posts, flooring, and paneling. Hickory was turned into hard, resilient tool handles and spokes for carriage wheels. Black locust was prized for barn timbers and wood pegs, called treenails. Mahoganies went into the best furniture.

The reduction of forest reserves since the Middle Ages, however, made timber increasingly expensive. This has brought about greater reliance by the construction and manufacturing industries, in modern times, on such composite wood products as plywood, chipboard, and fiberboard. These new materials are stable and do not swell or shrink as readily as natural lumber. They do not require long seasoning periods, and they can be waterproofed, fireproofed, and impregnated with protective chemicals. Plywood is particularly valuable to carpenters because it allows them to cover broad areas of framing in a short time.

Except for plywood, composite wood products, unfortunately, are not as strong as natural timber. These products cannot be bent or steamed into different shapes, as can plywood, so furniture built from them often appears boxy. Screws and nails cannot fasten them together securely unless plastic or metal inserts, fittings, and connectors are also used in the joints.

III. Woodworking Tools

Artisans down through the centuries have developed hand tools and power tools to bring out the special qualities of woods. They have invented a wide range of fasteners to hold pieces of wood together, and they have created waxes, shellacs, and varnishes to enhance and protect the beauty of wood (see Paint and Varnish; Shellac). Because the dimensions of wood building materials can change slightly under the influences of moisture and heat, the skilled woodworker must be able to anticipate these variations in order to maximize the strength and utility of the finished product.

A. Hand Tools

Most of the hand tools used today have changed little since the Middle Ages, the only major improvement being the use of steel instead of iron for cutting edges. The most common hand tools include saws, planes, and chisels and such miscellaneous tools as hammers and screwdrivers, which are used in conjunction with fasteners.

Several types of saws are used for various purposes. The familiar crosscut saw is used to cut across the grain of wood, and the ripsaw cuts with the grain. Curves are cut with the coping saw, which consists of a metal frame that keeps a narrow blade under tension. The precise cutting of joints can be done by hand with the aid of the backsaw, a thin rectangular blade stiffened by a metal bar along its back.

Planes are used to smooth and shape wood by means of a sharp steel blade (housed in a wood or metal casing) set at an angle to the surface to be planed. The depth of the cut can be varied by adjusting the distance the blade protrudes beneath the bottom surface of the plane. Planes are made in many sizes, and special planes are sometimes used to cut channels. Files of various shapes are also used to smooth and shape wood.

The flat-edged chisel and the semicircular gouge are used in certain instances to remove unwanted wood. The most important hand boring tools include the brace, the hand drill, and the push drill and their various bits.

Measuring tools are used to mark and check work for size and alignment. These tools include the steel tape measure, the folding wood rule, and the steel rule. The square and the trisquare are used to align or test right angles, and the spirit level is used primarily to test horizontal and vertical alignment. Work that requires gluing is usually clamped with the C-clamp, the bar clamp, and the hand screw, or gluing clamp.

B. Portable Power Tools

The development of electric power tools has greatly reduced the amount of time needed to perform a wide variety of tasks. The most important of these tools are the drill, the saw, the router, and the sander, all of which are available in several sizes.

Besides performing boring operations quickly, portable electric drills are often fitted with attachments that permit rotary sanding, polishing, and filing. Portable electric saws, often called circular saws, are extremely versatile and can cut either with or against the grain. The saber saw employs a narrow blade mounted vertically, which operates in an up-and-down motion, to cut curves and straight lines in relatively thin wood. The router, a very high-speed device, is used for cutting grooves and channels of many types, shaping straight or curved edges, and making decorative molding.

Two types of portable electric sanders are used to smooth surfaces and to remove the marks left by cutting tools before a finish is applied. The orbital sander causes sandpaper to vibrate in either a reciprocal or circular manner at a high frequency against the workpiece. It is less effective for many purposes than the belt sander, which runs a sandpaper loop at high speed against the workpiece.

C. Stationary Power Tools

Lumber yards, furniture factories, and other sites where large volumes of wood are worked employ large stationary machines designed for continuous operation. The radial saw moves back and forth on runners above the workpiece to make many types of cuts: crosscut, rip cut, miter, and bevel and cuts for many types of joints. The circular bench saw, which is sometimes used in the home workshop, cuts with a circular blade that is positioned in a slot on the surface of a metal table. This type of saw is used for many types of cutting. The band saw employs a large flexible steel blade in the form of a loop that is tensioned by means of two large pulleys positioned one over the other. Band saws are used for such heavy work as ripping logs into boards and cutting very thick wood.

Power planers, known variously as surface planers, thicknessers, and jointers, are used to speed the planing operation. On power planers, the workpiece is moved against rapidly rotating cutting edges.

IV. Carpentry

The art and trade of cutting, working, and joining timber into building structures is the oldest of the woodworking crafts. Before the use of steel and concrete became widespread in building construction, the carpenter played a major role in constructing the framework of buildings. In more recent times, the carpenter's part in construction has been concentrated in the areas of house building and in building the forms used to cast concrete.

Modern carpenters build the wood forms into which concrete is poured for high-rise buildings, highways, and hydroelectric power projects. Carpenters erect the scaffolds for workers in the other building trades. They install the partitions, doors, windows, flooring, roofs, and almost every other wood component of a structure, and they do nearly all of the major construction work on houses.

New fastenings and framing devices developed in recent decades have multiplied the uses for wood in construction and have increased the employment of carpenters. The use of component building systems–preassembled parts, or modules–instead of rough materials is increasing. In modular construction, entire sections of a structure are built in a factory and later assembled at the building site.

V. Joinery and Cabinetmaking

Joinery is the skill of fitting pieces of wood together precisely to form various articles. The word joiner was originally applied to workers in the late 16th century who practiced the craft of constructing and installing doors, windows, cabinets, and fittings for houses and ships. In England the term still applies to these activities, but in North America such workers are called carpenters, cabinetmakers, and millworkers. The term joinery now applies primarily to the skills of the cabinetmaker, the furniture maker, and the shipwright. Joint making is one of the highest skills of the woodworking craft. The most valued pieces of antique furniture were assembled by means of joinery in such a way that they have retained their beauty and utility down to the present.

Cabinetmakers are usually employed by manufacturers specializing in cabinets and furniture for storage and display. The skills of the cabinetmaker can be applied to the manufacture of pianos and harpsichords, household furnishings, ship's fittings, and other wood objects in which precise joinery, knowledge of wood qualities and characteristics, and adherence to blueprint specifications are required.

A. Basic Joints

Scores of joints can be used in wood assembly. The choice of joint depends on the quality of the wood used, the physical stresses expected in the finished product, and the preference of the artisan. Experienced woodworkers, however, usually choose the least elaborate joint that is suitable for a particular assembly. Most joints derive their strength from precise fit and glue; sometimes only wedging or pinning with brads or nails is needed.

The butt joint, used in box construction, is the simplest and most familiar joint. Two pieces of wood are simply placed end to end at a right angle and joined by nails, screws, or adhesives. The tongue and groove is best known as the joint used for installing hardwood floors. Today, tongue and groove joints are produced by mills, and wood so prepared is installed by carpenters.

A bevel joint is created by cutting the ends of wood obliquely, or with a bevel, so that the pieces to be joined meet at an angle in a continuous line. The term miter is applied to a bevel cut at 45°. The cuts for the miter joint are often handmade by sawing the wood along the precut grooves of a miter box.

The dado joint–frequently found in bookcases, shelves, and drawers–is made by cutting a channel in a piece of wood with a router. The edge of another piece of wood is then fitted, glued, and sometimes nailed into the channel.

The rabbet joint is similar to the dado, except that the channel, being at the end of one board, has an open side.

The lap joint is one of the most versatile and widely used joints. Variations on the lap joint are the cross lap, which is often used in building construction, and the half lap, end lap, and middle lap, which are used in cabinet and furniture making.

The dovetail joint and the notched joint are used in the manufacture of superior furniture. The dovetail joint is used to create a strong right angle from two flat pieces of wood. For the assembly of some wood items, woodworkers drill holes and insert wood dowels (round wood pegs) to create hidden joints.

The mortise and tenon joint is used to join two members perpendicularly. The tenon, a rectangular or square projection from the end of one member, fits snugly into the mortise cut in the second member. Variations on this joint have to do primarily with how far the tenon extends through the second member, and whether dowels or wedges are used to further strengthen the joint.

B. Finishing

The work of cabinetmakers and furniture builders is complete when the object being built is smoothed with sandpaper or steel wool to remove the marks left by the various cutting tools and, finally, when one or more finishes are applied to the object. Finishes serve to protect and preserve the wood and to bring out the beauty of the grain–or, in some cases, to cover up the imperfections of lower quality wood. Common finishes include waxes, oils, bleaches, fillers, stains, shellac, varnish, lacquer, sealers, and paints, including enamels.

Recently developed polyurethane sealers impart a clear, highly durable finish that provides excellent waterproof protection and brings out the charm and beauty of the grain. The grain of more expensive wood is often simulated on lower quality sheets of plywood paneling by means of photographic techniques.

Contributed By:

Roger Sheldon, B.A.

Associate Editor, The Carpenter, the official publication of the United Brotherhood of Carpenters and Joiners of America. Author of Opportunities in Carpentry Careers.

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"Woodworking," Microsoft® Encarta® Online Encyclopedia 2000

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