Weldclass WeldForce WF-160MST, Operating Instructions Manual

Page: 19 / 36

19
MMA Welding Techniques
- A Word for Beginners
For those who have not yet done any welding, the
simplest way to commence is to run beads on a
piece of scrap plate. Use mild steel plate about
6.0mm thick and a 3.2mm electrode.
Clean any paint, loose scale or grease off the plate
and set it firmly on the work bench so that welding
can be carried out in the down hand position. Make
sure that the Work Lead/Clamp is making good
electrical contact with the work, either directly or
through the work table. For light gauge material,
always clamp the work lead directly to the job,
otherwise a poor circuit will probably result.
The Welder
Place yourself in a comfortable position before
beginning to weld. Get a seat of suitable height
and do as much work as possible sitting down.
Don’t hold your body tense. A taut attitude of
mind and a tensed body will soon make you feel
tired. Relax and you will find that the job becomes
much easier. You can add much to your peace of
mind by wearing a leather apron and gauntlets.
You won’t be worrying then about being burnt or
sparks setting alight to your clothes.
Place the work so that the direction of welding
is across, rather than to or from, your body. The
electrode holder lead should be clear of any
obstruction so that you can move your arm freely
along as the electrode burns down. If the lead is
slung over your shoulder, it allows greater freedom
of movement and takes a lot of weight off your
hand. Be sure the insulation on your cable and
electrode holder is not faulty; otherwise you are
risking an electric shock.
Striking the Arc
Practice this on a piece of scrap plate before going
on to more exacting work. You may at first
experience difficulty due to the tip of the electrode
“sticking” to the work piece. This is caused by
making too heavy a contact with the work and
failing to withdraw the electrode quickly enough.
A low amperage will accentuate it. This freezing-
on of the tip may be overcome by scratching the
electrode along the plate surface in the same way
as a match is struck. As soon as the arc is established,
maintain a 1.6mm to 3.2mm gap between the
burning electrode end and the parent metal. Draw
Corner Weld
(Fig 1-19g)
Tee Joints
(Fig 1-19h)
Edge Joint
(Fig 1-19i)
Plug Welds
(Fig 1-19j)