Laboratory Glass-Working for Scientists - Sciencemadness Dot Org

BLOWPIPES
customary. There a 'glass-blower' is a person who works tubing in a
blowpipe flame.
Satisfactory blowpipes or bench burners are available from laboratory
furnishers. They usually have a range of jets to f^vc different
flame sizes. The changing of jets during work is avoided in a burner
with a turret head. The burners normally burn coal gas with either
compressed air or oxygen, or air-oxygen mixtures. Crossfire burners
produce a number of small flames which heat both sides of a tube at
once, as shown in FIGURE 3. They are very useful for large tubing.
Special burners producing a long thin flame ('ribbon burners') can be
FIGURE 3. Two crossfire burners
used for glass tube bending; they are made giving lengths of flame of
50,100,200 and 300 mm. A eracking-off burner giving a thin line of
intense heat is also made. All these special burners can be obtained
from Stone-Chance Limited.
I. C, P. SMITH (1947a) has given an account of the construction of
burners for the glass-worker. The adjustment of the flame size and
temperature with a given burner is best found by experience.
Hand Torches
A hand torch is a moderately light blowpipe designed to be held in
the hand and moved around the apparatus. Various hand torches
are available. We find the Flamemaster hand torch, made by Stone-
Chance Limited, to be very useful. This can be fitted with a number
of different jets. One gives a wide range of flame sizes with air-coal
gas mixtures. Three jets give different flame sizes of oxygen-coal gas
flames. With the largest of these, 4-cm diameter Pyrex tubing can be
worked with a single hand torch; with two hand torches as a crossfire,
6-cm bore tubing can be worked. A double-tipping device can
also be put on the torch in place of the usual nozzle; this gives two
small flames at an angle to each other of about 120°. This is useful
in ampoule sealing. Controls are provided on the hand torch for
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