GR3000

Welding Guidelines

general

This line of welding machines utilizes a process known as Shielded Metal-Arc Welding (SMAW). This process is used to bond metals by heating them with an electric arc created between the electrode and the work piece.

Electrodes used for shielded metal arc welding have two parts. The inner core is a metal rod or wire that should be similar in composition to the base metal. The outer coating is called flux. Various types of flux exist. Each coating is used for a particular welding situation.

While the metal is molten, it can be contaminated by elements in the air. This contamination could weaken the weld. The flux coating creates a protective barrier called slag that protects the molten metal from contaminants.

When current (amperage) flows through the circuit to the electrode, an arc is formed between the end of the electrode and the work piece. The arc melts the electrode and the work piece. The melted metal of the electrode flows into the molten crater and forms a bond with the work piece as shown in Figure 2.

NOTE: Discontinue using and discard electrodes that burn down to 1 to 2 inches from the electrode holder.

striking an arc

Place the bare end of the electrode in the holder. Grip the holder lightly to 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.

The best method of striking an arc is the scratching method. Drag the electrode at an angle along the surface much like striking a match. Upon contact with the plate, lift the electrode approximately 1/16 inch off the surface or it will stick (See Figure 3).

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.

electrode type and size

Four types of electrodes are recommended for this welder. The electrodes are commonly known by the AWS (American Welding Society) designation as follows:

1.E-6011 Deep penetrating

•Flat bead with deep penetrating arc.

•For rusted or dirty mild steel general repair work.

2.E-6013 General Purpose

•All position, smooth deposit rod with low spatter.

•For all mild steel and general purpose work.

3.E-7014 Fast fill

•Smooth bead and fast deposition

•Ideal for joints with poor fitup and general repair work.

4.E-7018-AC High Strength

•Ideal for pipes and structural applications.

•Low hydrogen reduces porosity for a strong weld.

NOTE: Only the E-7018-AC electrode is recommended for use with these welders. Other E-7018 electrodes are designed for use with higher open circuit voltages than these welders are capable of producing. Recommended electrode diameter is 3/32 inch or 1/8 inch.

Wire

Flux

Weld Slag

Crater

Work Piece

Figure 2 - Weld Components

1/16 inch

Same as Electrode Diameter

Figure 3 - Scratching Method

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