wire. Keeping the proper stick-out,
position the gun with the wire lightly
touching the work.Drag
Never push gasless wire. Remember it is
an electrode turned inside out. There is
a saying that “if it has a slag, you drag”,
or “push gas, drag slag”. This will keep
the slag behind the arc. When using
gasless wire, weld backhand. Tilt the
gun back, away from the weld pool in
the direction of travel about the same as
you would in stick welding. If the slag
tends to run ahead of the arc, increasethe drag angle. However, if the drag
angle becomes too great, you will end
up with an erratic arc and excessive
spatter, porosity, and poor bead shape.
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point the wire at the joint. The wire
angle to the joint should be about
40–45 degrees and maybe 1–2mm
onto the bottom plate. If you get the
position just right, the molten metal
will wash up onto the vertical plate.Wire slag
Flux-cored wires naturally form a
small ball of slag at the end of the wire
after each weld. The slag acts as an
insulator but it prevents good electrical
contact for starting. To ensure good
arc starting, the end of the wire must
be broken off or cut cleanly after each
weld run.Good wire
When buying gasless wire, choose
a good brand, as the chemistry is so
important. If you get porosity and a
lot of spatter but think you are doing
everything right — and you probably
are — cheap wire is likely to be
the offender.Vertical up and vertical down
Vertical up
Vertical-up welding is a technique
used for standing material where
large, stronger welds may be required.
The technique is basically the same for
gas-shielded or gasless, but you will
need to drop your power down.
I use a weave technique. Point the
wire at the toes of the weld bead
and pause slightly — to obtain good
penetration and to give time for the
slag to rise out of the sides — then
move quickly across the weld face
before pausing momentarily again at
the opposite side.
If you dwell too long in the centre,
you risk depositing too much weld
metal and producing an excessively
convex bead. Bad ones look like
grapes hanging down. So forget
the middle and focus on the sides.
Pausing at the sides then moving
quickly across the face allows weld
metal to wash in from either side.
The momentary pause on the side
also gives time for the slag to freeze/
solidify when using gasless.
Practise first. Take your time, and
if your build-up is too great then
speed up accordingly. If you want
a narrower weld, use a stringier
bead with a slight wiggle and move
upwards slightly faster.
It isn’t easy to create a really flat
weld. But practice is the best way.
Once your trial/test plate gets really
hot, you will find it harder still.
Starting with cold plates, not too
thin, is the way to go.Vertical down
Vertical-down welding is normally
shallow and narrow and is excellent
for sheet metal, panel steels, and
filling gaps where you don’t want
too much heat. Vertical down should
not be used on heavy material where
large welds are required.
Welding vertical down needs to be
done at a faster pace than down-
hand welding on flat material. Use a
similar power setting to down hand,
or slightly less.
When welding vertical down, use
the drag technique the same as for
gasless welding. Angle the torch in
the direction of travel so that the arc
force helps to hold the weld pool in
the joint. Move as fast as possible,
or at a speed that gives you a bead
shape that you are happy with. Try to
maintain the weld pool so that the
back of it looks like a horseshoe.
If the ripples on the bead look too
pointed, like an inverted V-point, your
travel speed is probably too fast.
If the ripples are wider than they
are long or oval-shaped, your travel
speed is probably too slow. Too slow
using gasless will also mean that the
slag will run over the weld pool.Wire choice
Most people I know choose wire
based on user appeal. Solid wire
and flux-cored wire are both easy
enough to use and are ideal for
novice or part-time welders working
in automotive, farming, and home
or hobby applications.
My personal preference, because
of operator appeal, is solid wire. I
feel it is slightly better on thinner
applications and there is no slag
to remove; it is ready to paint; and
is more aesthetically pleasing for
the bigger jobs that I do. But in
saying that, I keep my MIG loaded
with 0.9mm gasless wire for all the
mates who drop in and want this-
and-that welded. I’m owed about
20 slabs of beer.Porosity when you set the voltage too
high with flux-cored (gasless) wire