Fig. 199.—Dowelled Joint ready for Glueing.
[Fig. 201] shows the plan of a 3-in. cornice pole made to fit a bay window; the straight portions of the pole are generally turned in the lathe, the corner portions being afterwards jointed and worked up to the required shape. To avoid any difficulty in the setting out of the dowels, a disc of cardboard or sheet metal is made to the same diameter as that of the cornice pole; this disc is called a template. The positions of the dowels are set out geometrically, and the centres are pricked through with a fine-pointed marking awl (see sketch of template, a, [Fig. 201]). The template is put on the ends of the straight pole, and the dowel centres are pricked into the wood. The process is repeated on the ends of the corner block (b, [Fig. 201]), and if the holes be now bored at the centres indicated a true fit will be obtained.
| Fig. 200.—Method of Dowelling Thick Timber. | Fig. 201.—Method of Dowelling Cornice Pole by Means of Template. |
[Fig. 201 c] shows two portions of the circular pole jointed up to a corner block, and the dotted lines P indicate the direct line of pressure and shows the position for the cramp. When the glue is thoroughly set the corner block is sawn and spokeshaved to the desired shape as shown by the dotted line. This method is illustrated to show that, by the use of a suitable template, dowels may be exactly set out even when there is no straight or square face from which to use a marking gauge, and the method may, of course, be applied to many other examples of dowelling at the discretion of the workman.
| Fig. 202.—Dowelling a Mitred Frame. | Fig. 203.—Method of Frame Dowelling. (Long and Short Shoulders.) |
| Fig. 204.—Table Leaf with Dowels. | Fig. 205.— Block for Twist Bit. | Fig. 206.—Dowelling for Moulded Frame. | Fig. 207.— Cap. |
[Fig. 202] shows one corner of a mitred and dowelled frame. It needs little or no explanation beyond the fact that the dowels should be at right angles to the line of joint, and consequently the dowel at the outside edge of the frame will have to be much shorter than the others. This gives a strong and serviceable joint, suitable for many purposes.
Frame Dowelling.—[Fig. 203] shows one corner of a frame with long and short shoulders, such as occurs when the upright is rebated through its entire length. The holes in both pieces are bored for the dowels before they are rebated. This avoids any difficulty in endeavouring to bore with only one side of the twist bit in the wood. A similar type of joint is used on nearly all kinds of glass and door frames in cabinet work.