Thermal Arc Fabricator 140, Руководство по обслуживанию, Страница: 44 / 84

FABRICATOR 140, 180 OPERATION
Manual 0-4992 4-8 Janua r y 25, 2008
4.09 Establishing the Arc and Making
Weld Beads
Befo r e attempting to weld on a finished piece of wo r k, it
is r ecommended that p r actice welds be made on a sample
metal of the same mate r ial as that of the finished piece.
The easiest MIG welding p r ocedu r e fo r the beginne r to
expe r iment with, is the flat position. This equipment is
capable of flat, ve r tical and ove r head positions.
Fo r p r acticing MIG welding, secu r e some pieces of 16 o r
18 gauge (0.06” 1.5mm o r 0.08” 2.0mm) mild steel plate
6” x 6” (150 x 150mm). Use 0.024” (0.6mm) wi r e and
CO
2
shielding gas.
4.10 Pre-Weld Procedure
1. Check the OPERATION chapte r of this manual fo r
details on this equipment.
2. Set the welding voltage r ange switch at position 1
o r 2.
3. Set the wi r e feed speed cont r ol to about the 2.5
setting. Readjust as necessa r y.
4. Adjust the gas flow r ate to about 20 cubic feet pe r
hou r (15 - 20 lpm).
5. Review standa r d safe p r actice p r ocedu r es in
ventilation, eye and face p r otection, fi r e, comp r essed
gas and p r eventative maintenance. See Safety
Inst r uctions and Wa r nings chapte r included in this
manual.
4.11 Welding Procedure
1. Maintain the tip to wo r k distance (stickout) at 5/16”
to 3/8” (8 to 9mm) at all times.
2. Fo r t r ansve r se and longitudinal nozzle angles, see
section 4.07 Welding Gun Positions.
3. Hold the gun about 3/8” (9mm) f r om the wo r k, lowe r
the helmet by shaking you r head and squeeze the
t r igge r to sta r t the wi r e feeding, and establish the
a r c.
NOTE
Get in the habit of shaking the helmet down,
r athe r than using the hands. One hand must
hold the gun, and the othe r is often needed to
hold pieces to be tacked o r positioned.
4. Make a single down-hand (pulling) st r inge r weld
bead.
5. P r actice welding beads. Sta r t at one edge and weld
ac r oss the plate to the opposite edge.
NOTE
When the equipment is p r ope r ly adjusted, a
r apidly c r acking o r hissing sound of the a r c is
a good indicato r of co rr ect a r c length.
6. P r actice stopping in the middle of the plate, r esta r ting
into the existing weld c r ate r and continuing the weld
bead ac r oss the plate.
NOTE
When the gun t r igge r is r eleased afte r welding,
the elect r ode fo r ms a ball on the end. To the
new ope r ato r , this may p r esent a p r oblem in
obtaining the penet r ation needed at the sta r t
of the next weld. This can be co rr ected by
cutting the ball off with wi r e cutte r s.