[Illustration: FIG. 57.—STEPS IN SCARFING FOR A ROUND WELD.]
Heat and weld according to instructions on welding and finish the work smoothly with swages; then cut to a length of 6 inches, having the weld in the center.
Properly formed scarfs will produce perfect welds provided they are heated to the welding temperature when they are joined, but those improperly formed generally produce imperfect welds, although the heat is right.
=78. Flat Right-angled Weld.=—Fig. 58. Material required: two pieces of iron 3/4 × 3/8, 4-1/2 inches long.
Upset one end 1/8 inch larger than its diameters, as at _a_. By using backing-up blows as in the previous exercise, form a heel on one side, as shown at _b_, then resting the straight side on the anvil, draw out the point with the ball of the hammer, as at _c_. In drawing this point, the metal will spread and form a wide fan-shaped end, but by resting the right side _d_ on the horn of the anvil and delivering blows on the left, the latter edge will be straightened, leaving all projecting metal on the right.
[Illustration: FIG. 58.—STEPS IN SCARFING FOR A CORNER WELD.]
Upset one end of the other piece to the same dimensions, allowing this upsetting to continue along the metal about 1 inch. Form a scarf on the left edge at _e_, with the ball of hammer, using blows similar to those shown at _c_ and leaving the end square. Place them together to see if the points meet the heels; if not, make necessary alterations so they will.
Place the pieces in the fire, so that the side scarf will be removed with the left hand and the end scarf with the right. When placing for welding, the right-hand piece should be laid on the anvil and the left-hand one placed in its proper position on top of it. The inside corner should form a quarter-round fillet, the outside should be sharp and square, and the longer end cut off to make them both equal. Smooth all surfaces with a flatter. Sketch _F_ shows the weld completed; the dotted lines indicate the location of the scarfs before welding.
=79. T Weld.=—Fig. 59. Scarfing and welding. Material required: two pieces of 3/4 × 3/8-inch iron, 8 and 4-1/2 inches long.
[Illustration: FIG. 59.—STEPS IN SCARFING FOR A T WELD.]