BENDING LEAD PIPE.
If any ordinary piece of light lead pipe 11⁄2 inches in diameter is taken and pulled or bent sharply around it will crimple or crinkle at the throat; the larger and thinner the pipe the more it will become distorted.
There are many methods of making these bends in lead pipe, some with dummies, others with bolts, balls, etc., others cut the bends at the back, at the throat, or the two sides of the bend.
For small pipes, such as 1⁄2 to 1 inch and extra heavy, they may be pulled round without trouble or danger, but for a little larger size SAND BENDING is largely practiced as follows:
Take the length of pipe, say 5 feet, fill and well ram it with sand 2 feet up, then have ready a metal pot of very hot sand to fill the pipe 1 foot up, next fill the pipe up with more cold sand, ramming it as firmly as possible, stop the end and pull round the pipe, at the same time hammering quickly working the lead from the throat towards the back, which can be done if properly worked. N. B.—Care must be used not to reduce or enlarge the size of the bore at the bend.
Bending with Water.—It is a well-known fact that for such work, water is incompressible, but may be turned or twisted about for any shape provided it is enclosed in a solid case. To make the bend—the end of the pipe is stopped and a stop cock soldered into the other end; take the pipe at the end and pull it around, being careful that the water does not cool and shrink, and hammering quickly to take out the crinkle.
Bending with Balls.—This method is practiced with small pipe and also to take “dints” out in case of sand and water bending when a ball is sent through. Method: suppose the pipe to be two inches, then a ball is required 1⁄16 in. less than the pipe, so that it will run through the pipe freely. Now pull the pipe round until it just begins to flatten, put the ball into the pipe and with some short pieces of wood, say 2 in. long by 11⁄2 in. in diam., force the ball through the dented part of the pipe. The ball will run through all the easier if “touched” over with a candle end. Care must be used in forcing the ball back and forth not to drive it through the bend.
Table.—Weight of Sheet Lead.
| Inside Diameter | 3⁄8 | 1⁄2 | 5⁄8 | 3⁄4 | 1 | 11⁄4 | 11⁄2 | 13⁄4 | 2 |
|---|---|---|---|---|---|---|---|---|---|
| AAA, weight per foot, lbs., oz. | 2- 8 | 3- 0 | 3- 8 | 4-12 | 6- 0 | — | — | — | — |
| AA, „ „ „ | 1- 8 | 2- 0 | 2-12 | 3-12 | 4-12 | 6- 0 | 8- 0 | 8- 8 | 9- 0 |
| A, „ „ „ | 1- 4 | 1-12 | 2- 8 | 3- 0 | 4- 3 | 4-12 | 6- 8 | 6- 8 | 7- 0 |
| B, „ „ „ | 1- 4 | 1- 4 | 2- 0 | 2- 4 | 3- 4 | 3-12 | 5- 0 | 5- 0 | 6- 0 |
| C, „ „ „ | -10 | 1- 0 | 1- 8 | 1-12 | 2- 8 | 3- 0 | 4- 4 | 4- 0 | 4-12 |
| D, „ „ „ | - 7 | -12 | 1- 0 | 1- 4 | 2- 0 | 2- 8 | 3- 8 | — | — |
| E, „ „ „ | — | - 9 | -12 | 1- 0 | 1-10 | 2- 0 | 3- 0 | — | — |
Sheet lead is not the sameweight, bulk for bulk, owingto difference in organicformation, | |||||
| but a cubic footmay be said to weigh | 709 | lbs. | |||
| A square foot | 1″ | thick, | 59 | „ | |
| „ „ „ | 1⁄8″ | „ | 71⁄2 | „ | |
| „ „ „ | 1⁄10″ | „ | 6 | „ | |
| „ „ „ | 1⁄12″ | „ | 5 | „ | |
| „ „ „ | 1⁄15″ | „ | 4 | „ | |
| „ „ „ | 1⁄20″ | „ | 3 | „ | |
Sheet lead is sometimes made as thin as writing paper.