Wood Furniture Construction

Several different woods are often used in the construction of a single piece of furniture. For example, the term solid cherry or solid mahogany doesn’t mean that all of the wood used in the construction of that furniture piece is cherry or mahogany. It only means that all exposed parts of the piece are made of that furniture wood. The frame and other parts not visible to the eye, such as drawers and backs might be of another wood like gum or poplar.

The beauty of wood furniture is that no two pieces are exactly the same. Even among "matched" chairs in a dining set, there are variations in color and grain.

3 Main Wood Furniture Types

Wood furniture is generally described as one of these three types:

Solid Wood
Wood veneer (may be referred to as “all wood”)
Laminate

All Wood and Solid Wood Furniture

In wood furniture construction, the term "solid wood" means that each exposed part of that piece of furniture is made from one or more furniture woods. Veneers and laminates aren’t present in the finished piece. Solid woods are kiln-dried slowly to achieve moisture content in the vicinity of six percent and are then cut and shaped into pieces that provide the structural integrity of the furniture.

The term “wood veneer” means that thin slices of wood are bonded to composite boards or plywood in order to construct that piece of furniture. Veneers are used in both "solid wood" and "all wood" furniture construction. Besides wood veneer, artificial laminates, including those made of plastic, foil or paper, may be used in furniture construction. Laminates may be bonded to particle board or medium-density fiberboard and are usually photo-finished or may be engraved to simulate the look of wood grain.

Modern Furniture Construction Techniques

The interior construction of a piece of wood furniture often plays a more important role in its longevity than its beautifully finished or natural exterior wood. Today’s wood furniture construction uses a combination of solid hardwoods, plies and pressed wood.

For larger furniture surfaces, such as table tops, cabinet doors, dresser tops and sides, wide boards may be cut into narrower planks and then bonded back together.
Sheets of chipboard, particleboard, fiberboard or engineered wood may be used on the backs of cabinets or as base materials for tops and panels. These sheets are made by combining resins and bonding agents with wood particles, chips or flakes. Medium density fiberboard, or MDF, is an example of this process. When fused under intense heat and pressure, the resulting panel has consistent, uniform strength, is resistant to warping, cracking and splitting, and has no knots or other surface imperfections. MDF is used in all types of furniture.
Plywood and ply construction techniques are also used in making furniture. In furniture making, creating plies involves adding layers, each placed across the previous layer’s grain, to a solid wood or particleboard core. Adhesives are placed on each layer and then permanently bonded together under high pressure. Like chipboard, fiberboard and engineered wood, today’s ply construction is also very strong and highly resistant to warping. These large flat panels are then often framed in solid wood and covered by veneers to recreate the look of one large piece of wood.

Furniture Joinery

Joinery is a key part of the furniture construction process. Joinery methods used in furniture include:

Mortise-and-tenon joints
Dovetail joints
Dowel joints
Edge joints

Mortise-and-Tenon Joints

Mortise-and-tenon joints have been found in Egyptian furniture that dates back thousands of years. A joint is made using this method by fitting a somewhat square peg into a somewhat square hole. Actual shapes vary in practice, but in general, the tighter the fit between the mortise (hole) and tenon (peg), the stronger the joint. Glues, wedges and locking secondary pegs may be used in conjunction with the mortise and tenon to make the joint even stronger.

Dovetail and Dowel Joinery

Probably the next development in joinery was the dovetail joint, which is often seen in box or drawer construction. This is very similar to mortise-and-tenon joinery in that the joint is comprised of a wedge-shaped tenon (the "tail") on one component that overlaps a corresponding wedge-shaped slot in a second component. The portion of wood surrounding these slots is called the "pin." Except in the case of decorative joinery, all the pins are on one board, all the tails on another. The term "dovetail joint" can refer to one tail, or many in a row, such as you might find on the side of a. As in the case of mortise-and-tenon, the strongest dovetail joint is made when the pins and tails go all the way through the joint.

Today, dowel joinery largely replaces mortise-and-tenon joints of the past and dovetails are machine-cut and joined in seconds. Today’s furniture construction adhesives are stronger than wood, set rapidly, and can better stand harsh environments and heavy use than early adhesives used in furniture manufacturing. Nails, screws, and other fasteners – now machine made – have also seen substantial improvements and consistency over the fasteners once used in furniture construction.

Edge Joints

Edge joinery, which joins the thin, long edge of boards together to make a cohesive panel, is another ancient woodworking technique. Edge joints increase the width of the wood surface, such as for a table top. Usually, the edges are simply glued together, but sometimes a more elaborate joint is used. Simple edge gluing requires that absolutely straight and square surfaces be prepared for proper mating. More elaborate joinery, such as tongue-and-groove, is sometimes used to align mating surfaces.

Wood Furniture Finishes

Furniture that is described as "oak finish”,”maple finish”, “cherry finish", etc. may mean that the laminates used in the piece are made to look like those furniture woods, and/or that the piece of furniture has been stained using those finishes, even though the actual wood may be a less expensive or more readily available species.

A well-applied finish adds the finishing touch to the beauty and durability of wood furniture. A proper finish requires several coats of oil, wax, lacquer or paint to the wood surfaces. Sometimes the grain is "highlighted" using steel wool.

Other than hardwood stains, other types of finishes used in wood furniture construction are:

Pickled. Open pores of the wood are treated with a pigment for contrast. The background of the wood is either left natural or may be stained.
Glazed. Glazes are are often used to even out a lighter and darker areas after the staining and sealing process. Glazes may be transparent or semi-transparent.
Distressed. Distressed furniture finishes involve scuffing “beating up” the furniture to achieve an aged, rustic look with “character”. Distressing, or “fly specking” can be accomplished using anything from a chain with bolts to a paintbrush dipped in black paint to give the wood furniture an aged look.
Painted. Painted furniture can be used to harmonize with a color scheme in a room or achieve a cottage or cabin style. Painted furniture tends to show flaws in the wood, so pieces that are earmarked for a paint finish may need additional preparation to remove any imperfections in the wood before the finish is applied.
Lacquered. Clear and tinted lacquers may also be used to show off the beauty and grain of natural or stained wood. Tinted or opaque finishes change the color of the wood and can make two different woods appear to be the same. Lacquer finishes may be flat or buffed to a high gloss and provide water resistance and extra protection and durability to furniture.

Some furniture may be elaborately finished using many layers of lacquer or paint applied to achieve a weathered or aged look. Others may feature a gleaming, polished finish for a more contemporary look.