The distance A B, in [Fig. 84], must not be less than the distance A B in [Fig. 83].
| Fig. 83. | Fig. 84. |
The Two Parts of the Joint Marked.
Boring Away Waste.—Examine [Fig. 84]; the shaded portion in the centre has to be cut away, and it will greatly facilitate the removal of this waste piece by boring a hole with a twist bit at the position shown. The twist bit should be about 1⁄8 in. less in diameter than the width between the gauge lines G. The easiest method of boring out this hole is shown at [Fig. 85], which gives the correct position of the worker.
Fig. 85.—Vertical Boring previous to Chiselling.
Sawing.—The wood should be put in the vice as [Fig. 86]. Taking up a saw, with the index finger on the side of the handle, commence sawing, and proceed until you come to the position indicated by the dotted hand and saw A; this will leave a saw kerf or cut running diagonally from the shoulder line to corner of the wood. Release the vice and refix the wood so that it leans in exactly the opposite direction to [Fig. 86]; then reverse your own position and repeat the sawing, so as to cut another diagonal saw cut from the shoulder line to the corner. Fix the wood upright, as shown at [Fig. 87], and saw as shown, when you will find that the saw has no tendency to run out of the guide cuts already formed by the method used at [Fig. 86]. Remember, when commencing to saw at [Fig. 86], that it is necessary to saw inside the gauge line; otherwise the joint will be too slack, owing to the amount of sawdust removed by the thickness of the saw blade. The index finger on the side of the saw, pointing in the direction of the saw cut, will greatly help the worker to saw in a straight line, as it is natural to point with this finger to any object that is to be aimed at.
