Everlast POWER i-MIG 253DP Operator's Manual page 35

Section 2
humped appearance if not done correctly or if travel
is too slow. Whenever MIG welding with Alumi-
num, whether with the standard MIG gun or the
Spool gun ALWAYS push the gun. During Pulse
Welding, a Push angle is recommended wherever
possible, regardless of metal type. If using Flux
Core, a dragging motion is almost always recom-
mended.
Weaving (oscillating the torch from side to side in
one pattern or the other), particularly a MIG bead, is
a topic of controversy as much as whether to push
or pull the MIG gun. Stringer beads are often best
for novice welders. Stringers are simply straight
beads that move forward with little or no side to
side travel or oscillation. These will offer the sound-
est welds for a beginner. Stringer welds leave little
or no room for contaminates to enter the weld and
are the fastest to produce without creating an op-
portunity for cold lap. Moving too quickly however
with a stringer can create undercut which will weak-
en the weld. The best policy is to move a slow
steady speed, making sure the sides of the weld are
filled. If undercut is present, it is either from too
much voltage or moving before the wire has time to
fill the area the arc has melted.
Think of weaving as a method of "sewing" the metal
together. If weaving is of interest to you, start with
the basic weave pattern. Simple weaves using one
variation or the other of a cursive "e" motion are
best to begin with. Other weave patterns can be
used of course. C's, V'S, U's , Triangles and many
more weave patterns can be used depending upon
the application. Weaves are employed for a number
of reasons. Weaves are often considered to have a
more pleasing appearance and can help bridge gaps
where fit up is a problem. A weave is also frequently
used to manage heat build up. For example: when
welding vertically weaves are almost always used to
prevent the molten metal from sagging due to the
force of gravity. The major drawback of weaving is
that it introduces a greater possibility of getting in-
clusions and other forms of contamination in the
weld. Properly done weaving is a valuable tool, but
it must be practiced before employing it in any struc-
tural or critical application.
Metal Cleaning.
MIG welding requires a well prepped surface to ob-
Setup Guide and component Identification
BASIC MIG OPERATION
tain a sound weld. The removal of paint, rust mill
scale, or other contaminate such as grease should
be done before welding. Stick welding is more
forgiving of rust and mill scale, but when MIG
welding, contaminates will result in porosity and
inclusions in the weld, weakening it. A grinder will
usually prep the metal sufficiently to remove oxi-
dation and paint. However, to remove grease, a
degreaser such as acetone should be used. Do not
use any degreaser such a brake cleaner with chlo-
rinated solvents or death or serious injury may
occur! Pre-Clean stripped Aluminum with a dedi-
cated Stainless Steel Brush to remove oxidation,
even if metal is bright and appears clean. Alumi-
num will create an oxide layer quicly. Aluminum
such as diamond plate tread with mirror finishes
has an oxidized surface. Finish Aluminum with Ace-
tone, or Aluminum cleaner designed for welding.
A Steel MIG wire such as ER70S-6 or ER70S-2 in-
cludes a sufficient level of deoxidizers such as sili-
cone and copper that are formulated to allow it to
handle minor to moderate amounts of rust and
mill scale. These deoxidizers will float out most
moderate amounts of contaminates out of the
weld and will appear in the usual form of glassy
like deposits on top of the cooled metal. They are
easily brushed off before starting the next pass.
They should not be welded over. Any pinholes
that appear are a result of trapped gas in the weld
and should be ground out before the next pass. It
should be noted that some MIG wires such as
ER70S-3 have low levels of deoxidizers and must
be thoroughly cleaned and ground before welding.
Multiple Pass Welds.
One of the common misunderstandings that peo-
ple have when beginning to MIG weld is that if the
welder has the power, then a single heavy pass will
do to weld up in a single pass. This is a primary
way to introduce cold lap and incomplete fusion to
the weld. Single pass welds should not exceed
1/4" even with the heaviest wire the welder is ca-
pable of handling. A thick pass may also begin to
cool before contaminates and gas pockets have
the time to float out to the surface. It's far better
to make multiple smaller passes to complete a
plate weld for a higher quality result. For best re-
sults, this requires that most joints 1/4" and over
be prepared with a grinder to accept multiple weld
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