Some plumbers make this joint at two heats by pouring solder on one side and wiping it, and then by turning it over and doing the other half. When the joint is wiped at one heat and no iron used, the cloth should be lightly pressed on the part that is finished while pouring on more solder; if this is not done, the tin out of the melted solder runs back and sets in little bright projections on the surface of the joint and makes it look very unsightly. Sometimes a little V piece, P, Figure 42, is notched on the entering side of the opening before closing the elbow for soldering, so that it may pass outside of the other, and so prevent the bend being pressed into a sharper angle while being rolled round and soldered, but, with care, this can be done without, and so avoid leaving an edge inside for hair or anything of that kind to cling to, and also a possibility, if it should be cut a little too far, of solder running through.

The pipe should always socket in the direction of the current, and if the V piece is cut out as directed there would not be any such obstruction as illustrated at O, Figure 43, which shows it socketed the wrong way, in addition to the obstruction formed by not cutting out sufficient in the throat. If the elbow is made on a length of soldered seam pipe, the seam should always be arranged to be at the side in preference to either the throat or the heel of the elbow.

Figure 42.

Figure 43.