Xcel-Arc RazorWeld Razor TIG320 ACDC, Operating Manual

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Continued - Set Up Procedure for MMA (Stick) Welding:
6)
Connect the Earth Clamp securely to
the work piece or the work bench.
4) Place the electrode into the electrode
holder and clamp tight.
5) Strike the electrode against the work
piece to create and arc and hold the elec-
trode steady to maintain the arc
6) Hold the electrode slightly above the
work piece to maintain the arc while
travelling at an even speed to create and
even weld deposition. 7)
To finish the weld, break the arc by
quickly snapping the electrode away from
the work piece.
8) Wait for the weld to cool and carefully
chip away the slag to reveal the weld
metal below.
Razor
32OAC/DC TIG-MMA
ARC FORCE -
What is the Arc Force Control and what does it do?
During welding arc voltage drops as the arc gets tighter and can cause the electrode to stick to the work piece. Arc force should be set
according to the electrode diameter, electrode type, welding current and the technical requirement. When you set the arc force high the
machine senses the drop in voltage, as the electrode is about to stick/short circuit to the work piece the machine responds by increasing
the arc voltage and welding current momentarily (per millisecond). This boost in arc voltage/current blasts away base metal and elec-
trode to prevent the electrode from sticking itself to the work piece. High arc force means the molten droplet from the melting electrode
is larger with quicker transistion preventing the electrode from sticking, however too much arc force may create excessive spatter. Low
arc force will result in a softer arc with minimal spatter and a nice shaped weld bead, however it may lead to the electrode sticking to the
work piece easier, therefore the arc force should be adjusted to provide a smooth arc transistion between the electrode and workpiece
without it sticking and without providing excessive spatter. Higher Arc Force is more suited to thicker electrodes under low amperage
settings, out of postion welding, low hydrogen type electrodes where a forceful arc characteristic is preferred to maintain the arc and
better control penetration. Lower Arc Force is better suited to hardfacing and cast Iron electrodes where a soft buttery arc is preferred to
prevent the electrode material diluting too much with the base metal.
IMPORTANT NOTES -
For MMA (Stick) Welding
DC MMA ELECTRODE POLARITY -
What is the electrode polarity and why is it important.
When using a DC power source, the question of whether to use electrode negative or positive polarity arises.
Direct current flows in one direction in an electrical circuit and the direction of current flow and the composition of the elec
-
trode coating will have a definite effect on the welding arc and weld bead. Refer to the electrode manufacturers recommenda
-
tion for polarity choice.
With DC electrode (+) positive (reverse) polarity, more heat is generated at the workpiece. This produces welds with deep penetration
and a narrower weld bead and can reduce the incidence of lack-of-fusion defects in the weld.
DC electrode (-) negative (straight) polarity generates more heat at the electrode and produces welds with shallower penetration. DC
(-) negative electrode results in a higher burn off rate and therefore a higher deposition rate at a given current. It is generally the chosen
polarity for most GP Electrodes.
AC MMA ELECTRODE Welding.
AC MMA (Stick) welding came about from old technology of AC transformer welding machines. Electrodes were manufactured to run
on these AC machines. In fact, the electrodes made for AC welding will usually perform better on DC. AC is much louder and delivers a
more violent arc which can cause inclusions and slag in the weld. Generally AC is more diffcult to weld with than DC.
There can be a a phenomenon called “arc-blow” with DC current where a magnetic field can build up and push the arc off to one side. If
you are having issues with magnetism creating arc blow then the AC can help stabilise the arc and bring things back in line.
But for most other applications, AC is not needed. There are some Aluminium MMA electrodes available that do require AC current.