Flat Welding - Craftsman 113.201392 Owner's Manual

FLAT WELDING
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Figurel i
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f p,.JLET WIELD
LAPWELD
TACK
WELOS
Fiat welding includes all types of joints in which the weld
is horizontal, and the electrode is fed down as m the practice
welds of previous pages. The five types of joints in figure 1
can be welded in the flat position.
Butt welds on light material should be practiced first on
scrap stock. Use 16-gauge mild steel sheet metal (approxi-
mately 1/16-inch thick) and 5/64-inch rods wqth the welder
set at approximately 30 to 50 amperes. Butt edges of metal
together and tack-weld approximate]y every three inches
(fig. 2). (Tack welds are small beads 1/4 to 3/8-inches in
length.) Place bars of scrap iron under ends of the work to
provide an air space above the table. Simply move the rod
in a straight line directly above the edges to be (greed
If the weld burns through in places, reduce the welding cur-
rent or increase the rate of travel. Some difficulty may be
experier_ced in starting the arc at these low current settings.
However, once the arc Js started, there will be sufficient
heat to make a sound weld. After laying a bead, turn the
work over and inspect the underside which should also have
a small uniform bead. To prevent burning through where
the edges are not butted t_ghtly together, move the rod back
and forth with short quick strokes in the dlrechon of the
weld to brTdge the gap and give the metal in the crater a
chance to solidify (fig. 3).
Butt welds on sheet metal hghter than 18 gauge should
not be attempted by the beginner without the use of a
back-up strip (fig 4) This consists of a bar of copper
clamped tightly against the underside of the seam to absorb
the heat of the arc and prevent the weld from burmng
through. To assure complete penetrahon with butt welds
on 8-gauge metal or heavier, a 1/16 to 3/32-inch gap
should be altowed between them (fig 5) Insert a wedge or
screwdriver between the plates when tack-welding to mare-
tam the gap, then turn the piece over, so the tack welds are
on the underside
Use enough current to melt edges of ploFes to o depth of
at least one-half their thickness Clean off the slag and
respect it for smoothness, penetration and height of rem-
forcernent A good weld should have a reinforcement shghtly
more than flush with the surface (f_g 6)- Turn the plate
SLIGHT
GAP
SHEET
METAL
L____I\
RACK-UP
STRIP
Frgure 4
Figure 3
Fcgure 5
Figure 7
t-.t-- GAP
FIRSTPASS
T_IRD PASS _ SECOND PA_S
REIHFORCING
_ (WEAVE)
_PAS$ BlrffWELD
Figure 8
E V-WELD
Figure 9
E-BEVEL W£LO
Figure 10
over and weld a slm_iar bead on the other side (fig 71 A
hEgher welding current can be used on this s_de as there ws
no danger of burning through and fusion with the first
bead will be assured
Although butt welds can be made on steel plates up to
3/8-inch thick, with a 295-ampere machine using 1/4-inch
rod, the same results can be obtained with the 180 and
230-ampere machines if edges of plates are beveled (fig B)
Metal of almost any thickness can be welded m th_s manner
by depositing a number of beads, one on top of the other
until the groove _s completely filled. If the plate can be
welded from both sides, always use a double bevet (fig. 9)
]f only one plate _s beveled, the angle should be at 45 de-
grees fflg. 10).
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