If you
can get a cone which can be screwed into an inch pipe, file the
opening of the cone to 1/16 in. diameter, and jacket the whole
with a 2-1/2-in. pipe. The flame end of this burner tube should be
about 4-1/2 in. above the cone opening and should be covered with
gauze to prevent flame from snapping back. When lighted, the point
of the blue flame, which is the hottest part, should be just in
the hole in the bottom of the kiln. Such a burner will be cheaply
made and will furnish a kiln temperature of 1400 degrees, but it
will burn a great deal of gas.
A plumber's torch of medium size will cost more in the beginning,
but will be cheaper in operation. Whatever burner is used, the
firing should be gradual, and with especial caution the first
time. By experiment you will find that a higher temperature is
obtained by placing a 1-in. pipe 2-ft. long over the lid hole as a
chimney. It would be still more effective to get another iron
pail, 2 in. wider than the kiln, and get a down draft by inverting
it over the kiln at whatever height proves most suitable. --G. L.
W.
** How to Make a Small Medical Induction Coil [63]
The coil to be described is 3-1/2 in.
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