OM-291417 Page 69
13-8. Troubleshooting – Porosity
Porosity - small cavities or holes resulting from gas pockets in weld metal.
Possible Causes Corrective Actions
Insufficient shielding gas at welding arc. Increase flow of shielding gas at regulator/flowmeter and/or prevent drafts near welding arc.
Remove spatter from gun nozzle.
Check gas hoses for leaks.
Ensure proper contact tip to work distance.
Hold gun near bead at end of weld until molten metal solidifies.
Wrong gas. Use welding grade shielding gas; change to different gas.
Dirty wire. Use clean, dry wire.
Eliminate pick up of oil or lubricant on wire from feeder or liner.
Workpiece dirty. Remove all grease, oil, moisture, rust, paint, coatings, and dirt from work surface before
welding.
Use a more highly deoxidizing wire (contact supplier).
Excessive contact tip to work distance Ensure proper contact tip to work distance
13-9. Troubleshooting – Excessive Penetration
Excessive Penetration - weld metal melting through base metal.
Possible Causes Corrective Actions
Excessive heat input. Select lower voltage and reduce wire feed speed.
Increase travel speed.
13-10. Troubleshooting – Lack Of Penetration
Lack Of Penetration - shallow fusion between weld metal and base metal.
Possible Causes Corrective Actions
Improper joint preparation. Material too thick. Joint preparation and design must provide access to bottom of groove while
maintaining proper welding wire extension and arc characteristics.
Improper weld technique. Maintain normal gun angle of 0 to 15 degrees to achieve maximum penetration.
Keep arc on leading edge of weld puddle.
Be sure welding wire extends not more than 1/2 in (13 mm) beyond nozzle.
Insufficient heat input. Select higher wire feed speed and/or select higher voltage range.
Reduce travel speed.
13-11. Troubleshooting – Incomplete Fusion
Incomplete Fusion - failure of weld metal to fuse completely with base metal or a preceding
weld bead.
Possible Causes Corrective Actions
Workpiece dirty. Remove all grease, oil, moisture, rust, paint, undercoating, and dirt from work surface before
welding.
Insufficient heat input. Select higher voltage and/or adjust wire feed speed.
Improper welding technique. Place bead in proper location(s) in joint during welding.
Pause on groove side walls when using weaving technique.
Keep wire on leading edge of weld puddle.
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