Longitudinal Joint

This is made when two edges are united, either on the roof, etc, or in pipe-making. The weld or seam of the pipe made by hydraulic pressure and not drawn is said to be sometimes so defective as to yield to very slight pressure. The best pipe is made by pressing the molten metal between a tube and mandril by hydraulic pressure, and not by drawing. This sort is jointless. Another kind is noticed under Seam Joint.

Mitre Joint

An obsolete method of forming a branch joint by cutting out an angular notch in the main pipe and a corresponding projection in the branch and mitring the two with solder. However well done, it is wasteful of solder and wholly unfitted for soil-pipes, being both weak and altogether wanting in the proper smoothness of interior required for clean flushing.

Overcast Joint

Overcast Joint is another name for striped joint.

Overcast Ribbon Joint

This is a ribbon joint made as explained under that head, but finished off by being striped or overcast with the copper-bit in such a way as to present, instead of a smooth surface, one covered with facets.

Overlapping Joint

Overlapping Joint is a mode of connecting two pieces of lead in the direction of the fall or current sometimes, but not by any means frequently, adopted, and is made by turning up two contiguous edges unequally, one about 1 in. and the other about 1 in., so that the additional half-inch may be carefully turned down again over the 1 in.

upstand. This being done the two edges are well and closely dressed together with or without tingles between them, and are either left standing up or folded and doubled and dressed down close to the surface, as in Fig. 145. No roll is used, nor is a hollow left in its interior as in the hollow roll joint. This variety thus compactly rolled together is otherwise termed a welded joint, and is very suitable for balcony and verandah floors, etc.

Pipe Joint

Lead and compo. tubing are joined by means of cone joints, or ordinary unions soldered on, or else with wiped, blown, or copper-bit joints. Different lengths of lead soil and waste pipes are united with flange, block, wiped, copper-bit, or slip socket joints, the latter not being applicable to soil-pipes, which in common work are often lengthened by working one end a little way into the other and soldering them together with the copper-bit. When the work is properly done vertical soil-pipes have tacks of 7 lb. or 8 lb. lead every 3 ft. or 4 ft. apart, not less than 10 in. by 9 in., strongly soldered to pipe so as to secure it to the wall on alternate sides with about three wall hooks, or if there are flange or block joints one tack between every two of them suffices. Waste pipes must be protected from breaking away at the joints by similar precautions, though the tacks may be proportionately smaller according to the weight it is their province to support. Pipes of large diameter are usually made as noticed under Seam Joint.