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POS}ITtON
WELDING
BUTT WELl)
In order to derive the greatest benefits from your we{der,
you should practice
until you can make a welded
joint
in almost any conceivable
position. The ability
to do this
is especially
useful when making repairs on machinery as
the amount of welding in most cases is small and does not
warrant disassembling the parts to weld them in the flat
position. Welds of this type have been classified into three
groups according to their location and are referred
to as
vertical,
horizontal
and overhead
welds (fig.
t). Of the
three positions, vertical welding win be used the most and
should be practiced
first. Skill gained in this type of weld
will make horizontal and overhead welding easier.
VERTICAL
WELDING
The two methods of welding in the vertical
position are
commonly
known
as "'vertical-down"
and
"vertical-up*'
welding
(fig. 2). In the former the bead is started at the
top and welded in a straight
line downward,
in the latter
the bead is started at the bottom and welded up, _suaIty
with a weav{ng motion.
The chief difficulty
encountered
with any position weld is
keeping the molten metal in the puddle
from falling
out.
To prevent this the arc must be held as short as possible and
the weld puddle kept fairly small so it wilt solidify rapidIy.
Verfica{-down
welding is the easiest to perform and is used
on material up to 1/8-inch _hlck. Before attempting a vertical
weld, run a few practice beads to get the "'feel" of the
arc. Tack-weld a piece of scrap iron to an old practice plate
so it is positioned vertically
(fig. 31. Use 1/8-inch
rods for
the first welds and a current of about 75 to 115 amperes.
Experiment with various amperage settings until you are
using the highest current you can handle. Hold the rod at
right angtes to the plate laterafly, with the tip pointed up
at the angle shown in figure 3. Start the weld at the top
of the plate and move the rod in a straight line downward.
The correct rate of travel can be determined by gradually
reducing the speed unti{ molten metal in the puddle con no
longer be kept in place. Then, increase the speed slightly
while watching the puddle, arc length and angle of the rod.
A short arc provides better controf of the mohen metal.
Fol{ow the same procedure with 3/32
and 5i32_inch rods.
ft will be noted that the larger the rod the more difficuh
i_
is to control the puddle.
For this reason smaller diameter
rods are a{ways used for position welding.
Lap or tee-joints are made by simply directing the arc into
the corne_ of the joint as in fiat welding
and moving the
rod down the seam at a steady pace. _utt welds may require
more practice, as there is a tendency to burn through on
light gauge material
Jf this occurs, continue until the seam
is comp{eted and patch the hole by chipping the slag and
wire brushing until dean. Then, with slightly lower current,
strike an arc on the weld directly above the hole and quickly
bring the rod down to the fower rim of the hole to deposit
a small amount of metal. Raise the rod for an instant to
let the metal solidify and repeat until the hole is welded.
Hotd a long arc when raising, so there will be no metal
deposited except when the rod is lowered. Any hesitation
in the rate of travel wl]i cause a "'burn through." if this
happens repeatedly,
lower the welding current.
Leave a siight gap between pieces for butt welds on material
over 3!32-inch
thick, inspect the back side after welding
for small bead along the seam, indicating complete pene-
tration (fig. 4). Butt ioints on material
around
3!16-inch
thick shou{d be welded on both sides.
vertical-down
welds
may
be made
on heavier
material
by
laying
in a number
of passes (fig. 51, however,
this practice
is not recommended
as it takes longer
than
a heavier
single-
pass weld
made
by the verfica{-up
method.
%
VERTICAL-DOWN
WELDING
F_gure
2
Figure
3
....
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IIIIIIII1,11 [ ,llllll IIII, III
A SMALL _EAgON
BACK ST{IFINDICATES
COMPleTE P_IfETRATION
Figure
4
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