This is your guide line for the first weld bead. Use 3.2mm a and approximately 125 amps.

Lay the plate on the bench so as its length is across your body. Get used to welding across your body‑this is the only way you can see where you're going from start to finish of the electrode. While welding towards yourself may seem easier for achieving a straight line, the electrode and holder will soon block your view. After having placed a bead down the centre of the plate, chip off the slag and put down another alongside so that the edge (toe) of the second bead just laps up to the top of the first bead. See Fig. 9. Continue laying down beads of even width and height. After several runs, the pad may begin to get too hot. You may reduce to hand hot by periodic quenching in water in your practice session although this is not a recommended practice for most actual welding applications.

Always fill the crater at the end of the bead by raising the electrode tip slightly and moving back over the crater area, pausing a little before withdrawing to break the arc. Unfilled craters are weak and a possible source of weld cracking.

When joining up to a previous bead, first chip the old crater free of slag. strike an arc in the joint a little ahead and move back into the crater and establish a full width molten pool before progressing along the weld. See Fig. 11.

In carrying out a series of welds, experiment with a little higher current (say 140 amps) and lower current (say 90 amps) and note the differences in running, spatter, bead shape, etc. you will note that you can obtain satisfactory welds with lower currents once the pad is hot. Also you should now be trying to differentiate between the slag and metal in the molten pool and achieve the feel of controlling both.

Do your experimenting with electrode angles, travel speeds, joining up beads etc., while doing your pads. It's more economical on steel and will assist you in laying down better fillet welds and butt welds at an early stage. See Fig. 10.

Weaving

So far we have concentrated on straight weld beads, varying the rate of travel to vary the bead width. A wider bead can of course be obtained by using a larger electrode, but there are some occasions where we wish to achieve a slightly wider bead or better shape with the same size electrode. A technique of lateral movement of the tip across the weld puddle called weaving can be employed. The width of weaving is usually restricted to a movement of twice the diameter of the electrode. Try a few weaves to produce a slightly wider bead, ensuring that the molten pool is maintained under the arc and keeping the slag back, pausing slightly at the end of each lateral movement. Fig. 11.

You may obtain full value out of your steel pad by laying down a second pad at right angles to the preceding pad layer and building up the height indefinitely. Padding, properly done is a means of rebuilding worn areas to size and is used extensively in maintenance work on shafts etc.
 

Concentrated welding in one spot can cause distortion by localized overheating and residual stresses. Wherever possible, balance the welding evenly over the job. Figure 13 illustrates a typical procedure for padding a shaft to size.

We have spent considerable time on our basic work. If this is understood and practiced then its application to the following joints will require less detailed information to enable you to follow its application.