Firepower MST 220i, Operating Manual

Page: 68 / 96

FIREPOWER MST 220i
BASIC WELDING 4-10 Manual 0-5343
Gap varies from
1/16” (1.6mm) to 3/16” (4.8mm)
depending on plate thickness
Joint
Open Square Butt
1/16” (1.6mm) max
1/16” (1.6mm)
Single Vee Butt Joint
Not less than
70
°
Double Vee Butt Joint
1/16” (1.6mm)
Lap Joint
Tee Joints
(Fillet both sides of the
joint)
Edge Joint
Fillet Joint
Corner Weld
Plug Weld Plug Weld
Not less than
70
°
Single Vee Butt Joint
Not less than
45
°
1/16” (1.6mm) max
Art # A-10672
Figure 4-19: Typical Joint Designs for Arc Welding
Arc Welding Technique - A Word to 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 1/4" (6.4 mm) thick and a 1/8" (3.2 mm) 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 downhand
position. Make sure that the work 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 Weldor
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.