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Basic Welding Machine and Cables
The choice of welding machine is based mostly on
the following factors:
primary voltage, e.g. 240 Volt or 380 Volt
•
output amperage required, e.g. 140 amps
•
output required, e.g. AC or DC +/-
•
duty cycle required, e.g. 35% @ 140 amps
•
method of cooling, e.g. air-cooled or oil-cooled
•
method of output amperage control, e.g. tapped
secondary lugs
or infinitely variable control.
•
For example, the Smootharc 175 Multiprocess
connects to 240 Volt supply (15 amps Input), has an
output of 175 amps DC @ 35% duty cycle.
Having decided on a welding machine, appropriate
accessories are required. These are items such
as welding cables, clamps, electrode holder,
chipping hammer, helmet, shaded and clear lenses,
scull cap, gloves and other personal protective
equipment.
BOC stocks a huge range of personal protective
equipment. This combined with BOC's extensive
network ensures fast reliable service throughout
the South Pacific.
11.3 Welding Technique
Successful welding depends on the
following factors:
selection of the correct electrode
•
selection of the correct size of the electrode for
•
the job
correct welding current
•
correct arc length
•
correct angle of electrode to work
•
correct travel speed
•
correct preparation of work to be welded.
•
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11.4 Electrode Selection
As a general rule the selection of an electrode
is straight forward, in that it is only a matter of
selecting an electrode of similar composition
to the parent metal. It will be found, however,
that for some metals there is a choice of several
electrodes, each of which has particular properties
to suit specific classes of work. Often, one
electrode in the group will be more suitable for
general applications due to its all round qualities.
The table following shows just a few of the wide
range of electrodes available from BOC with their
typical areas of application.
For example, the average welder will carry out
most fabrication using mild steel and for this
material has a choice of various standard BOC
electrodes, each of which will have qualities
suited to particular tasks. For general mild steel
work, however, BOC Smootharc 13 electrodes will
handle virtually all applications. BOC Smootharc
13 is suitable for welding mild steel in all positions
using AC or DC power sources. Its easy-striking
characteristics and the tolerance it has for work
where fit-up and plate surfaces are not considered
good, make it the most attractive electrode of its
class. Continuous development and improvement
of BOC Smootharc 13 has provided in-built
operating qualities which appeals to the beginner
and experienced operator alike.
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