Campbell Hausfeld GR3000 Welding System User Manual


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GR3000
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13
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.
Welding Guidelines
1/16 inch
Same as Electrode Diameter
Figure 3 - Scratching Method
Flux
Slag
Weld
Wire
Crater
Work Piece
Figure 2 - Weld Components
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