Woodwork Joints | Page 4

the board to be joined by using two handscrews as shown at the left hand of the illustration. At the right hand of the sketch a wooden cramping arrangement of the box type is given, and by wedging up the boards are closed together. It is obvious that if this type of box cramp be used it will prevent the boards buckling and the handscrew method at the left may be dispensed with.

THE HALVED JOINT
The halved joint is frequently known as half-lapping, and sometimes as checking and half-checking. In the majority of cases it is made by halving the two pieces, i.e., by cutting half the depth of the wood away. There are, however, exceptions to this rule, as in the case of "three-piece halving" (or, as it is sometimes called, "third lapping") and in the halving of timber with rebated or moulded edges. Halving is one of the simplest methods of connecting two pieces of timber, especially where it is desired to make frames and bracket supports for either inside or outside use.
[Illustration: Fig. 28.--Frame, with various halved joints. These joints, numbered 1, 2, 3, etc., are shown in detail in Figs. 29 to 38.]
Fig. 28 shows the elevation of an imaginary frame which is indicated as made up of a number of halving joints; it shows also the application of the various joints to this class of work. Each joint used in the construction of this frame may be dealt with separately. The numbers marked on Fig. 28 refer to the individual joints, shown separately in Figs. 29 to 38.
[Illustration: Fig. 29.--Halved Corner Joint.]
[Illustration: Fig. 30.--Halved T Joint.]
Fig. 29 shows the "Halved Joint" at the corner of the frame where the two pieces form a right angle (see Fig. 28, 1). Each piece is halved and shouldered at opposite sides, thus forming a perfect fit one with the other and giving a strong joint with a minimum amount of labour. For inside work the joint would be glued and screwed together, the screw heads being countersunk so as not to come in contact with the cutting iron of the plane when levelling off the work. For outside work, in exposed positions where the work will have to withstand the weather, the alternative method of smearing the joint with paint or with a mixture of varnish and white lead would be advisable, the joint being nailed or screwed. Fig. 29 shows the two pieces separated.
Fig. 30 shows a similar joint to the above, but in this case the top rail runs through and it is generally spoken of as a "Halved T Joint" (Fig. 28, 2). It may be used in nearly all cases where a top or bottom rail runs through an upright. The method of securing the joint is as before. Fig. 30 shows a sketch of the joint separated.
[Illustration: Fig. 31.--Oblique Halving with Shoulder.]
[Illustration: Fig. 32.--Oblique Halving.]
At Fig. 31 is shown an "Oblique Halving Joint," where the oblique piece, or strut, does not run through (Fig. 28, 3). This type of joint is used for strengthening framings and shelf brackets; an example of the latter is shown at Fig. 48. A strut or rail of this type prevents movement or distortion to a frame diagonally (generally spoken of in the trade as "racking"). Fig. 31 shows the joint apart.
Fig. 32 is an example of Oblique Halving with the upper piece running through (Fig. 28, 4). This joint is used in similar positions to Fig. 31, and has in some cases the disadvantage of showing end grain at the top of the frame. The sketch shows the two pieces separated.
Fig. 33 is "Dovetail Halving," the dovetail running through the top piece (Fig. 28, 5). This is a strong joint, used where outside strain is likely to occur in the top piece, the dovetail preventing the rail from being drawn away from the shoulder. The two pieces are shown separate.
[Illustration: Fig. 33.--Dovetail Halving.]
[Illustration: Fig. 34.--Mitre Halving.]
At Fig. 34 is seen "Mitred Halving," a somewhat weak joint, but necessary in mirror frames, etc., where good appearance is required on the face side (Fig. 28, 6). Its use is obvious if the face of the frame be moulded with beads or other sections which require to intersect one with the other. This also applies if the frame be moulded on its face edges.
Fig. 35 is a halved joint with one side of the piece dovetailed (Fig. 28, 8). This joint is used in similar positions to Fig. 33, and rather less labour is required in the making. The two pieces are shown separate for clearness.
Fig. 36 indicates the "Halved Joint," the pieces at one end showing a double dovetail (Fig. 28, 7). This particular joint is seldom used except for Manual Training purposes. The illustration shows a sketch of the