If any ordinary piece of light lead pipe 1-1/2 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 1-1/2 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.