Wedged And Halved Scarfed Joint. Fig. 144.

Material:

2 pieces, 6 3/8" X 1 1/2" X 7/8".

This joint is used in heavy wooden construction in places where it is necessary to have the greatest tensile strength, though it is obviously a weaker joint in regard to resistance to a shearing stress, if concentrated at the joint, than is that described in Exercise 72.

After the pieces a and b have been accurately squared and made parallel, proceed as follows:

1. Fitting the joint: Lay the pieces side by side in their relative positions, and with a sharp knife mark distinctly, by the edge of square, the lines c, d upon both edges of each piece. Notice that the lines are 2" from one end of each, and 3/8" from the other end.

Fig. 144. - Halved and Wedged Scarfed Joint.

2. With a fine, hard pencil, mark lines square with the edges lightly upon both sides.

3. With a sharp gauge, lay out upon both sides of each piece in the order given, the lines f, g, h; be careful not to continue the lines beyond the point where they will cut away, or they will cause a blemish upon the finished model. Work from the face side and edge at all times.

4. Go over c, d, e, k with the knife, carefully.

5. In cutting to the marks, leave half of the knife or gauge marks upon the piece wanted. Saw in the following order: c, k to C, and d, k to g, f, h. With a sharp chisel, cut e, cutting back of the fines in the thickness of each piece. To insure a tight fit at g, the joint should be perfectly straight: if there is any deviation, it should be a little rounding in its length. If this should be done very carefully, and if all the work is executed with accuracy, all members of the joint will fit perfectly.

6. After all the fitting is done, clamp the pieces in their permanent position, and with a knife mark the key ways and fit the wedge keys, which may be allowed to project 1/4" upon each side, if desired.

7. Smooth and sandpaper.