Welding
Non-Ferrous
Metals
Treating
Welding
Cast Iron
Welding
Ferrous
Metals
3
General Instructions
Flame Adjustment:
All the work described in this chapter should be done
with the neutral oxy-acetylene
flame. To secure
a neutral flame, always start with an excess of acetylene, then increase the flow
of oxygen (or decrease the flow
of acetylene) until the excess acetylene feather just disappears. Check flame
adjustment frequently. An excess
of acetylene is easy to spot, but an excess of oxygen is not always evident to
the eye, although it will usually
cause the molten metal to spark excessively. When
starting steel welding practice, do not use the strongest flame which your welding
head can produce. (The strongest
flame is the one which would separate slightly from the tip if the flow of each
gas were increased only slightly.)
Use the regulator delivery pressures recommended by the maker of your torch for
the tip size in use, but do
not hesitate to cut back the flame length slightly by adjustment of the torch
throttle valves. Too harsh a
flame will make
it hard for you to control the weld puddle until you have acquired some skill.
Better to have a flame which is
a bit too soft than one which
is too harsh.
You will not be able to weld as fast, but you will have better control.
Experiment with flame size as you move
along, but start out on the soft side. Welding
Positions: The four primary positions,
as shown in the various sketches which follow, are described as:
Flat –
Surfaces of the work lie in a plane parallel to the ground.
Vertical – Both
the surfaces of the work and the line of the weld are perpendicular to the ground.
Horizontal –
The surfaces of the work are perpendicular to the ground, but the weld line is
parallel to the ground. Overhead
– Same as flat, except that welding is performed
from below the work rather than above it. Continued
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