OM-194 199 Page 266-11. Troubleshooting – Lack Of PenetrationLack Of Penetration – shallowfusion between weld metal andbase metal.Lack of Penetration Good Penetration S-0638Possible Causes Corrective ActionsImproper joint preparation. Material too thick. Joint preparation and design must provide access to bottom of groove whilemaintaining 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.6-12. Troubleshooting – Incomplete FusionIncomplete Fusion – failure of weld metal to fuse completely withbase metal or a preceeding weld bead.S-0637Possible Causes Corrective ActionsWorkpiece dirty. Remove all grease, oil, moisture, rust, paint, undercoating, and dirt from work surface beforewelding.Insufficient heat input. Select higher voltage range and/or adjust wire feed speed.Improper welding technique. Place stringer bead in proper location(s) at joint during welding.Adjust work angle or widen groove to access bottom during welding.Momentarily hold arc on groove side walls when using weaving technique.Keep arc on leading edge of weld puddle.Use correct gun angle of 0 to 15 degrees.6-13. Troubleshooting – Burn-ThroughBurn-Through – weld metal melting completely through base metalresulting in holes where no metal remains.S-0640Possible Causes Corrective ActionsExcessive heat input. Select lower voltage range and reduce wire feed speed.Increase and/or maintain steady travel speed.
