To form the scarf of a ring or collar, one end is bevelled, as at b in [Fig. 2885] and after the piece is bent to a circle it is cut off and bevelled as at a. When a slight band is to be welded, and it is difficult to steady the ends to bring them together, a clamp may be used to hold them as in [Fig. 2886].
Fig. 2887.
[Fig. 2887] represents a tongue weld, and it is obvious that to insure soundness the wedge piece should fit in the bottom of the split, which may be well closed upon it by the hammer blows.
Fig. 2888.
[Fig. 2888] represents an example of a V-weld applied to welding up a band that is to be square when finished, and as the lengths of the sides must be equal when finished, the side on which the weld is made should be made shorter, so that in stretching under the welding blows it will be brought to its proper length. The V form of weld is employed because it stretches less in welding than the lap weld. The V-piece to be welded in should bear at the bottom of the V, and the weld made by fullering.