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Craftsman 113.201480 Owner's Manual page 25

50-295 amp dual range variable control ac arc welder

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bent
and edges fused
together
by melting
down
the excess
metal
to form
a bead
(fig.
6). No filler
rods
are required.
The
carbon-arc
torch
is ideally
suited
for
brazing
and
soldering
small tubing.
Cast
and
malleable
iron
can
be brazed
with
excellent
results.
A bronze
filler
rod
and
common
brazing
flux
are
used. Rust, paint
or grease
must be cleaned
from
the area
to be brazed.
If it is a butt joint, such as a crack in a casting,
grind
or
chip
out a beveled
groove
as for
arc welding.
Apply
the heat
from
the arc tame
gradually
by passing
it over
the metal
surrounding
the joint.
When
the casting
has become
warm,
concentrate
the arc flame
at the joint.
The important
thing
to remember
when
brazing
cast iron
is never
to heat the edges
of the ioint to the mehing
point.
The temperature
of the work
should
not exceed
the melting
point of the filler
rod. The carbons
are held
as close to the
work
as possible
without
causing
the metal
to bubble.
Hold
the filler
rod in the left hand
and heat the end of it sfghfly
by passing
it through
the arc flame.
Then
dip
the heated
end in brazing
flux.
Raise the torch
slightly
and
deposit
some of the flux at the part of the joint being
heated.
When
the surface
of the heated
metal
takes
on a shiny
or wet
appearance,
the filler
rod can be applied.
Do not put the rod directly
;n the flame,
but hold
it on the
work and let the heat
of the edge of the flame
and the work
melt the rod.
Deposit
only enough
metal
to fill
the part
of
the joint
that
has been
coated
with
flux.
As the metal
is
being
deposited,
move
the torch
along
the
joint
slowly,
applying
flux to the rod and ioint as required.
Copper
and copper-base
alloys
such as bronze
and
brass
may also be brazed,
but as their
melting
temperatures
are
so close to the melting
point
of the filer
rod,
the process
in many cases becomes
one of welding
rather
than brazing.
A bronze
filler
rod
and common
brazing
flux
are used.
Most
non.ferrous
metals
can be welded
by manipulating
the torch
and fiHer rod in the same manner
as for brazing,
with the exception
that the edges of the joint are heated
to
the melting
point
before
depositing
the filer
metal.
,:If the
work is a copper
alloy,
use common
brazing
flux.
If it is an
aiumlnum
alloy,
use aluminum
flux.
The filler
rod should
be of the same
analysis
as the work.
If regular
welding
rod is not avaifable,
strips of the parent
metal
may be used.
A back-up
strip should
be used when welding
thin material
Small
diameter
carbons
and
}ow amperage
setting
are
used for soldering.
The torch
is held so the work
is just within
the visible
edge
of the flame.
Apply
the soldering
flux
and
play
the flame
over
the work
untt
it is just hot enough
to
melt the solder.
If the ioint
is to be sweat-soldered,
tin the
surfaces
to be joined,
then
press them together
and reheat,
adding
more solder
at the edges of the joint.
One of the most practicaJ uses of the arc torch is heating
metal for bending, forging,
etc. Set the torch for a wide,
enveloping-type
flame and apply the heat to the bottom of
the work (fig. 7). Since a red heat is not visible through the
dark welding glass, the helmet must be raised periodically
so the work can be inspected to avoid overhec_ting. To pro-
tect the eyes from the rays of the arc, hold the torch to
one side a:nd above your head. The carbon-arc
torch is
not recommended for welding mild-steel. However, it may
be used for brazing
mild-steel if the metat is too thin for
regular metallic-arc welding,
CUTTING
and
olher
miscellaneous
operations
CUTTING
WITH
THE ELECTRIC ARC
Arc cutting is simply the continuation
of a "burn through"
such as you probab]y
experienced
when practicing
with
light sheet-metal welding.
When this action is accelerated
by using extremely high currents, it becomes an efficient
method of cutting metals. Affhough the edges of the cut
surfaces are not as smooth as when cut with o saw or
oxyacetylene
torch, there are many cases where such pre-
cision is not required.
Ordinary
mild-steel
welding
rods
may be used. The current will vary with the type and thick-
ness of the material. In general, high currents increase the
speed of cutting but also increase the rod burn-off rate and
width of the cut.
i
11 i1,,111
START
C_T
HERE
Figure
I
__
_MOLTEN METAL.
'
STEEL
RTAIHER
i
,11
ii ii
i
!1
iii
,I
t-17

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