The Butt Seam on Round Pipe.

Pipes that are placed in a horizontal position are usually butt seamed, as a stronger seam can be made in that manner. This form of seam is also used in lengthening traps, bends, etc. To prepare a round pipe for butt seaming, the ends of the pipe should first be made perfectly round by inserting a drift plug and dressing the lead up close to it. The ends of the pipe should be rasped true and then shaved clean. Also shave the pipe for a distance of ? inch each side of the edge. A piece of stiff writing paper should then be rolled up the size of the pipe and inserted in the ends. This paper will prevent any lead from running into the pipe and leaving rough edges, as these afterward form an obstruction.

The burning should be commenced at the under side of the pipe, Fig. 31, and proceed both ways from the starting point and finish at the top. If the beginner has successfully overcome the difficulties of the seams preceding this he will find no trouble in making a strong and workmanlike seam on this pipe. Pipes are seldom used heavier than the grade known as D for this class of work, and for that reason it is seldom necessary to add lead to these seams. But if a hole should be burned in the pipe on the under side, lead should be added to the top side of the pipe and then made to follow the flame to the desired spot. This will be found a quicker and more certain method than attempting to add lead directly to the hole. A properly burned pipe should show the full thickness of the pipe when cut with a saw.

Through Seam on Round Pipe.

Where heavy pipe that is to be used under pressure is to be joined it must be burned through to provide strength, and the ends prepared in the same way as just described, but the ends must also be trimmed off all the way around with a slight bevel reaching from the outside almost to the inside bore of the pipe. The bevel must stop so as to allow a narrow square butt end on each pipe. Then when a piece of paper has been placed on the inside to prevent lead running into the pipe, the two ends when butted will present a V-shaped groove, as shown in Fig. 32, reaching all around the pipe. The burning is commenced at the bottom, as shown in Fig. 31, and the two ends securely united. The groove is then filled by burning on additional lead from a thin cleaned strip until the groove is filled and the pipe made as heavy and strong at this point as anywhere on its entire length.

This seam is used almost exclusively on pipe in a vertical position, and is similar to the horizontal lap seam. The pipe is prepared by spreading the lower piece of pipe with a drift plug one size larger than the size of the pipe used. The end of the pipe intended to enter this socket is rasped to a bevel edge, as shown at a, Fig. 33. This end is then shaved clean, as is also the inside of the socket. The pipe is then placed into the socket, which is then dressed up tight against the inserted pipe, as shown in Fig. 34. The exposed edge is then cleaned and burned, as described for horizontal lap seams.

The Tee Joint on Round Pipe.

With a pair of compasses set the diameter of the pipe that it is desired to insert, and strike a circle on the pipe which is to receive the tee. With a tap borer, or any other device, cut out a circle of lead, leaving about ¼ inch to turn up. Then draw this remaining lead up by means of a bending iron and a heavy piece of iron, such as a chisel, as shown at B in Fig. 35, until the hole is large enough to receive the piece intended for it, the end of which should be beveled with a fine rasp, as shown at a. The lead should then be dressed back against the pipe, after which remove the piece and shave clean, and proceed to burn as described for the lap seam on round pipe, and as shown in Fig. 36. Care must be taken in dressing up the lead flange to dress it slowly so as to avoid weakening the lead.

Lining Tanks.

The lining of chemical tanks being the principal work of the chemical plumber, a description of how this work is done will probably be of some use to the beginner. In preparing lead sheets for a tank the sheets should be cut so as to give the most seams on the bottom, because of the greater ease in making them. In large tanks I find it convenient to put the bottom in first, cutting it to make an easy fit, and then the sides are put in. These are cut to allow ¾-inch lap on the bottom.

The lead sheets are laid on the floor, or some other smooth place, which has previously been swept clean, and then dressed out smooth. This can best be done by using the wooden dresser to take out the large wrinkles and then smoothing with a lead flap. This flap is simply a piece of sheet lead about 3 inches wide and 12 inches long, one end of which is drawn into a roll to fit the hand. Then mark the laps and bend them to the desired position. The under side of the lap should be shaved clean, as also the lead under the lap, to facilitate fusion.

If the tank is over 18 inches high the lead must be fastened to the sides with bullseyes. These are made by countersinking places in the sides of the tank. The lead is then dressed into these holes and it is held in place with large headed brass screws, which are covered by burning over the heads. Lead for the purpose is taken from lead strips. The building up process is resorted to in covering these screw heads.

The lead should be arranged so as to avoid corner seams as much as possible, as it is quite a difficult job to get the proper thickness of lead in such seams. No rule can be given for cutting lead to fit a tank, as tanks are of such a variety of sizes and shapes, and the lead is of so many widths, that the mechanic must study how to cut the stock without waste and have as few seams as possible.