Dovetail joint
A dovetail joint or simply dovetail is a joint technique most commonly used in woodworking joinery. Noted for its resistance to being pulled apart (tensile strength), the dovetail joint is commonly used to join the sides of a drawer to the front. A series of pins cut to extend from the end of one board interlock with a series of tails cut into the end of another board. The pins and tails have a trapezoidal shape. Once glued, a wooden dovetail joint requires no mechanical fasteners.
The dovetail joint probably pre-dates written history. Some of the earliest known examples of the dovetail joint are in furniture entombed with mummies dating from First Dynasty of ancient Egypt, as well the tombs of Chinese emperors. The dovetail design is an important method of distinguishing various periods of furniture.
Methods
Dovetails can be made with hand tools or machine tools, often with an electric router and using one of a range of commercially available jigs or templates. Although it is technically a straight forward process, hand-cutting dovetails requires a high degree of accuracy to ensure a snug fit and so can be difficult to master. The pins and tails must fit together with no gap between them so that the joint interlocks tightly with no movement. Thus the cutting of dovetails by hand is regarded as a mark of skill on the part of the craftsperson.
The angle of slope varies according to the wood used. Typically the slope is 1:6 for softwoods and a shallower 1:8 slope for hardwoods. Often a slope of 1:7 is used as a compromise - perhaps using a dovetail template for marking it out.
Types of dovetail
Through dovetail
The photograph at the top of this page shows a through dovetail (also known as plain dovetail) joint, where the end grain of both boards is visible when the joint is assembled.[1] Through dovetails are common in carcass and box construction. Traditionally, the dovetails would have often be covered by a veneer. However, dovetails have become a signature of craftsmanship and are generally considered a feature, so they are rarely concealed in contemporary work.
Use for:
- Carcass and box construction
Half-blind dovetail
A half-blind dovetail is used when the craftsman does not wish end grain to be visible from the front of the item. The tails are housed in sockets in the ends of the board that is to be the front of the item so that their ends cannot be seen.
Half-blind dovetails are commonly used to fasten drawer fronts to drawer sides. This is an alternative to the practice of attaching false fronts to drawers constructed using through dovetails.
Use for:
- Attaching drawer fronts
Secret Mitred Dovetail
The secret mitred dovetail joint is used in the highest class of cabinet and box work. It offers the strength found in the dovetail joint but is totally hidden from both the inside and outside corners by forming the outer edge to meet at a 45-degree angle while hiding the dovetails internally within the joint.
Use for:
- Carcass and box construction to hide the dovetails completely from view
Sliding dovetail
The sliding dovetail is a method of joining two boards at right angles, where the intersection occurs within the field of one of the boards, that is not at the end. This joint provides the interlocking strength of a dovetail. Sliding dovetails are assembled by sliding the tail into the socket. It is common to slightly taper the socket, making it slightly tighter towards the rear of the joint, so that the two components can be slid together easily but the joint becomes tighter as the finished position is reached.
Use for:
- Joining shelves to cabinet sides
- Joining cabinet bottoms to sides
- Joining horizontal partitions to shelves
- Joining adjacent sections of expandable table frames
- Joining drawer fronts to sides
- Joining front rails of web frames to cabinet sides
- Joining neck and body in some guitars
Full-blind dovetail
The full-blind dovetail obscures the mechanics of the joint altogether. This variant is used in fine work when the craftsperson requires the strength of a dovetail but without the visual intrusion of the interlocking pins and tails. Two versions of this joint are the secret double-lapped dovetail and the full-blind mitred dovetail. The former presents a very thin section of end grain on one edge of the joint, whilst the latter does not. When used in drawer construction, a "full-blind dovetail" is sometimes referred to as a "French dovetail."
Use for:
- Fine cabinet or box work where strength is required without a visible joint
Non-woodworking dovetails
Dovetails are most commonly, but not exclusively, used in woodworking. Other areas of use are:
- Linear guides, for example on a lathe
- Attaching turbine blades to the shaft in jet engines and other applications
- Clockmaking: dovetailing a new tooth, when replacing broken teeth in clock gears.
References
- ^ Dovetail Joints, WoodworkDetails.com
See also
Further reading
- Kirby, Ian. The Complete Dovetail: Handmade Furniture's Signature Joint (1999). Hertford, England: Stobart Davies Ltd.