| Fig. 267.—A Single Through Dovetail. | Fig. 268.—Through Dovetails on Carcase Work (P, Pins; T, Tails). |
Through Dovetailing.—One of the simplest forms of the dovetail joint is shown in [Fig. 267], where two pieces of timber are joined by the method known as "through" dovetailing. This method is used in everyday practice for joining the corners of frames, bracket trusses, and a hundred and one other articles.
[Figs. 268] and [269] show the method of through dovetailing as applied to the making of boxes, plinths, and general carcase work; it is used in positions where no objection can be taken to the end grain showing on each side of the finished work. In the case of plinths and furniture cornices the foundation frame is made of yellow pine or other cheap wood, and the more expensive and rare timbers are glued and mitred around in various thicknesses and shapes, thus saving the more costly material and strengthening the construction by the method known as laminating. In many cases all that is necessary is to veneer the face sides, thus covering and hiding any unsightliness.
| Fig. 269.—Dovetails for Boxes, etc. | Fig. 270.—Lap-dovetailing for Drawers. |
Lap-dovetailing.—[Fig. 270] is an example of lap-dovetailing, such as is used where a drawer side joins with the drawer front. It is not permissible to allow the end grain of the timber to show at the front of a drawer, and this is why resort is had to the lap-dovetail. As the most general use of the dovetail is for this and similar purposes, we shall therefore deal fully with the methods of marking out and the making of this class of joint.
Angles.—A most important point in the construction of a dovetail is to avoid having the angles of the pins and tails too acute. An inclination of one in eight is considered correct; no hard and fast rule need be obeyed, but the variation should on no account be less than one in six.
| Fig. 271.—How to obtain Correct Angles for Dovetail Template. | Fig. 272.—Squaring and use of Template. |
[Fig. 271] shows a simple method to obtain the correct angle. Take a piece of timber and plane up the face edge (A, B) true and straight; mark out a line (C, D) at right angles to the face edge and space off 8 ins. as shown; now measure a distance of 1 in. (D, E), and join E to point eight. This will give the correct angle for the dovetails, and it may then be transferred to the joiners' bevel. Many workers who are constantly on dovetail work make a zinc template to the exact angle and keep it specially for the purpose ([Fig. 272]).
Squaring.—Another important point to remember is that the drawer sides must be true and squared to an exact length and planed up to thickness; otherwise the finished drawer will be in winding and out of truth.
To true and square the ends of drawer sides, drawer backs and drawer front, a most useful little machine is the mitre trimmer; failing this, excellent results can be obtained by using the shooting board.