Arc Welding Basics

! WARNING

Operating Instructions and Parts Manual

Inverter Technology Arc Welder

reduce tiring of the hand and arm.

Note: Always keep the jaws of the holder clean to insure good electrical contact with the electrode.

Be careful not to touch the work

piece or welding bench with the electrode as this causes arc flashes.

There are two methods which can be used to start or strike the arc; the tapping method and the scratching method. In the tapping method, the electrode is brought straight down and tapped on the work piece.

With the scratching method, drag the electrode at an angle along the surface much like striking a match. Regardless of method, upon contact with the plate, immediately raise the electrode a distance equal to the diameter of the electrode or it will stick to the surface. Always hold the electrode pointed into the weld.

Note: Should the electrode stick to the work piece, break it loose by quickly twisting or bending at the holder while pulling upward. If the electrode does not break loose, disengage the electrode by releasing it from the holder.

Five basic techniques affect weld quality. These are: electrode selection, current setting, weld angle, arc length, and travel speed. Proper implementation of these techniques is necessary for good weld quality.

Electrode Type and Size

The correct choice of electrode type involves a variety of factors, such as welding position, work piece material type, thickness, and condition of surface to be welded. The American Welding Society, AWS, has set up certain requirements for each type of electrode.

All electrodes are classified into five main groups: mild steel, high-carbon steel, special alloy steel, cast iron, and nonferrous such as aluminum. The majority of arc welding is done with the electrodes in the mild steel group.

The electrode material should corres- pond with the work piece material.

Flux coatings are made for use with either AC (alternating current), DC (direct current) reverse polarity, or DC straight polarity, although some function well on both AC and DC current.

Commonly Used Electrodes

1. E-6011 Deep Penetrating

•The strong arc force and rapid solidification of the metal makes vertical and overhead welding easier with this rod.

•Where time does not permit rust, scale or paint removal, this rod penetrates rapidly and easily.

•Acceptable for AC or DC welding current (reverse polarity).

2. E-6013 General Purpose

•All position, smooth deposit rod with low spatter.

•For all mild steel and general purpose work.

•Acceptable for AC or DC welding current (straight or reverse polarity).

3. E-7014 Iron Powder

•A general purpose "drag" rod for all positions.

•Ideal for situations where fit between metal pieces is poor.

•The iron powder in the flux coating combines with the filler rod to make a smooth deposit with very little spatter.

AWS Electrode Classification

E - 6 0 1 3

E = Electrode

60= Mild steel

70= High strength Steel

1= Electrode can be used in all positions

2= Electrode is restricted for use in flat or horizontal position

only Flux type

•Ideal for ornamental work.

•Acceptable for AC or DC welding current (straight or reverse polarity).

4. E-7018 Low Hydrogen

•An all position high strength electrode designed to produce low hydrogen content combined with excellent mechanical properties.

•Acceptable for AC or DC welding current (reverse polarity).

Current

The correct current involves the adjustment of the welding machine to the required amperage setting. Current represents the actual flow of electricity and is regulated by a knob on the welder. The current used depends on the size (diameter) and type of electrode used, position of the weld, and the thickness of the work piece.

Consult specifications listed on the electrode package or generalized chart in the Operation section. Excessive current burns through light metals, and the weld bead is flat and porous or the bead undercuts the work piece (See Fig. 11). The bead appears high and irregular if the current is too low.

5º - 45º

Travel Angle

Work Angle

Figure 8 - Weld Angle

Weld Angle

Weld angle is the angle at which the electrode is held during the welding process. Using the correct angle ensures proper penetration and bead formation. As different welding