Common Gmaw (Mig) Shielding Gases; Troubleshooting Guide For Gmaw (Mig) Welding Process - Hobart IronMan 240 Owner's Manual

9-16. Common GMAW (MIG) Shielding Gases

This is a general chart for common gases and where they are used. Many different combinations (mixtures) of shielding gases have been developed
over the years. The most commonly used shielding gases are listed in the following table.
Gas
Spray Arc
Steel
Argon
Flat &
Argon + 1% O
2
Horizontal Fillet
Flat &
Argon + 2% O
2
Horizontal Fillet
Argon + 5% Flat &
CO Horizontal Fillet
2
Argon + 10% Flat &
CO Horizontal Fillet
2
Argon + 25%
CO
2
Argon + 50%
CO
2
CO
2
Helium
Argon +
Helium
2
Tri-Mix
1 Heavy Thicknesses
2 90% HE + 7-1/2% AR + 2-1/2% CO

9-17. Troubleshooting Guide For GMAW (MIG) Welding Process

Problem
Wire feed motor operates, but
wire does not feed.
Wire curling up in front of the
wire feed rolls (bird nesting).
OM-284833 Page 36
Short Spray Arc
Circuiting Stainless
Steel Steel
Flat &
Horizontal Fillet
Flat &
Horizontal Fillet
All Positions
All Positions
All Positions
All Positions
2
Probable Cause
Too little pressure on wire feed rolls.
Incorrect wire feed rolls.
Wire spool brake pressure too high.
Restriction in the gun and/or assembly.
Too much pressure on wire feed rolls.
Incorrect cable liner or gun contact tip size.
Gun end not inserted into drive housing properly.
Dirty or damaged (kinked) liner.
Application
Short
Circuiting Spray Arc
Stainless Aluminum
Steel
All Positions
1
All Positions
1
All Positions
All Positions
Increase pressure setting on wire feed rolls.
Check size stamped on wire feed rolls, replace to match
wire size and type if necessary.
Decrease brake pressure on wire spool.
Check and replace cable, gun, and contact tip if
damaged. Check size of contact tip and cable liner,
replace if necessary.
Decrease pressure setting on wire feed rolls.
Check size of contact tip and check cable liner length
and diameter, replace if necessary.
Loosen gun securing bolt in drive housing and push gun
end into housing just enough so it does not touch wire
feed rolls.
Replace liner.
Short
GMAW-P
Circuiting
Aluminum
All Positions All Positions
All Positions
All Positions
All Positions
All Positions
Remedy