Removing Seams; Bolt And Rivet Cutting; Hole Piercing; Heating - Craftsman 113.201392 Owner's Manual

MOVI[ ROe Lip AND -_, ._
_. START
CUT
HERE
F_gure 2
To make a trial cut, place a bar of steel approximately
1/4-1nch thick on the table so that ene end projects over
the edge. Use a 3/32-inch rod and a current setting of
around 140 amperes. Hold the rod as shown in figure 1 and
strike an arc on the top corner at the edge of the bar where
the cut is to be made. Feed the rod into the molten puddle
and keep the crater burning through as the rod is moved
across the bar. To catch the molten metal, place a metal
container an the floor directly under the cut.
When cutting metal heavier than 1/4-inch, the arc is started
at the bottom corner and worked up and down vertically
as shown in figure 2, advancing the bottom of the cut
slightly ahead of the top of the cut to permit molten metal
to run out more easily. If a smooth edge is desired, the
pieces can be ground on an abrasive wheel. Electrodes
designed especially for cutting may cllsobe used.
REMOVING SEAMS
In addition to cutting, the electric welding arc can be used
for beveling the edges of material to be welded, gouging
out cracked welds for rewelding or removing tack-welds.
The surface of the metal being worked upon should be ap-
proximately in the vertical position, or tipped slightly toward
the arc (fig. 3). Start at the bottom of the seam to be gouged
out and work upward. The rate of speed will depend upon
the depth of the groove and the amount of metal removed.
BOLT AND RIVET CUTTING
Removing rusty bolts or rivets is an easy job with an electric
arc welder. The arc is struck on the head or nut of the bolt
and worked around in a slight circular movement until the
head is completely melted off (fig. 4). A punch is then
used to drive out the remaining part. The boff or rivet can
be removed by heating the head almost to the melting point,
then quickly shearing it off with a cold chisel Care must be
taken not to cause the bolt to become welded to the metal
HOLE PIERCING
Another useful appllcahon of the welding arc is piercing
holes in metal. Coated metallic electrodes are best for
this purpose because of their small size and insulation
afforded by the coating. The process is extremely fast and
a surprisinglycleon circular hole can be made. Far practice,
place a piece of scrap iron I/4-inch thick (or less) on the
table and allow it to project over the edge as for arc
cutting. Use a 3/32-inch rod and the same current as for
cutting. At the place where the hole is to be pierced, strike
an arc and hold it until a molten puddle is formed. Then
push the electrode down against the molten puddle and
force it through the plate. It ispossible to hold the e4ectrode
against the melted plate because the metal core melts off
faster than the coating The coating (not the rod) touches
the molten metal (fig. 5). The gap malntamed by the pro-
truding coahng prevents the metal core of the electrode
from sticking or freezing to the plate.
If a larger diameter hole is desired, first pierce a hole as
described. Then, holding a fairly long arc, melt the edges
of the hole away by moving the rod around it (fig. 6). Holes
of almost any diameter can be made. To pierce a hole
through material thicker than 1/4-inch, work from the
underside.
HEATING
The carbon arc prowdes a convenient method for localized
heating of all metals. Simply strike an arc on the part to be
heated and "play" it across the surface unfit the required
temperat_ureis reached
GOUGINe
Figure 3
MOL1TN
Figure 4 FJgure 5
Figure 6
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