Hobart Welding Products OM-227 978B manual Troubleshooting − Lack Of Penetration

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9-11. Troubleshooting − Lack Of Penetration

 

Lack Of Penetration − shallow

 

fusion between weld metal and

 

base metal.

Lack of Penetration

Good Penetration

 

S-0638

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.

Incorrect polarity.

Check polarity required by welding wire, and change to correct polarity at welding power source.

9-12. Troubleshooting − Incomplete Fusion

 

Incomplete Fusion − failure of weld metal to fuse completely with

 

base metal or a preceeding weld bead.

 

S-0637

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 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.

9-13. Troubleshooting − Burn-Through

Burn-Through − weld metal melting completely through base metal resulting in holes where no metal remains.

S-0640

Possible Causes

Corrective Actions

Excessive heat input.

Select lower voltage range and reduce wire feed speed.

Increase and/or maintain steady travel speed.

OM-227 978 Page 36

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Contents OM-227 978B ProcessesDescription 2007−04From Hobart to You Table of Contents − MIG Welding Gmaw Guidelines − Parts ListTypical MIG Process Connections Symbol Usage Marks a special safety messageArc Welding Hazards Electric Shock can killARC Rays can burn eyes and skin Welding can cause fire or explosionFlying Metal can injure eyes Buildup of GAS can injure or killCalifornia Proposition 65 Warnings EMF Information Principal Safety StandardsAbout Pacemakers LES Fumées ET LES GAZ peuvent être dangereux UNE Décharge Électrique peut entraîner la mortIndique un message de sécurité particulier LE Soudage peut provoquer un incendie ou une explosion DES Particules Volantes peuvent blesser les yeuxDES Pièces Chaudes peuvent provoquer des brûlures graves LE Bruit peut endommager l’ouïeRisque D’INCENDIE OU D’EXPLO LA Chute DE L’APPAREIL peut blesser’EMPLOI Excessif peut SUR DES Organes Mobiles peuvent provoquer des blessuresBoulevard, Rexdale, Ontario, Canada M9W 1R3 téléphone En ce qui concerne les stimulateurs cardiaques− Specifications Symbols And DefinitionsSpecifications − DefinitionsDuty Cycle And Overheating Volt-Ampere CurvesAmperes OutputInstalling Welding Gun − InstallationInstalling Work Clamp Process/Polarity Table Changing PolarityInstalling Gas Supply Selecting a Location And Connecting Input Power Installing Wire Spool And Adjusting Hub Tension Electrical Service GuideTools Needed Installing Contact Tip And Nozzle Connecting Optional Spool Gun Appropriate settingThreading Welding Wire − Operation ControlsWeld Parameter Chart For 230 VAC Model 227 949-B − Maintenance &TROUBLESHOOTING Routine MaintenanceOverload Protection Drive Motor Protection MonthsChanging Drive Roll Or Wire Inlet Guide Turn Off power before replacing contact tipReplacing Gun Contact Tip 030/.035 Groove Stamped 023/.025 Groove Stamped .030/.035Disconnect gun from unit Cleaning Or Replacing Gun LinerTo Reassemble Gun Replacing Switch And/Or Head Tube Troubleshooting Table Trouble RemedyOM-227 978 − Electrical Diagram Circuit Diagram227 951-B − MIG Welding Gmaw Guidelines Typical MIG Process ConnectionsTypical MIG Process Control Settings Wire Size Amperage RangeThickness to Amperage a AmperageHolding And Positioning Welding Gun Conditions That Affect Weld Bead Shape PushPerpendicular Drag Short Normal LongGood Weld Bead Characteristics Poor Weld Bead CharacteristicsGun Movement During Welding Troubleshooting − Excessive Spatter Troubleshooting − PorosityTroubleshooting − Excessive Penetration Possible Causes Corrective ActionsTroubleshooting − Incomplete Fusion Troubleshooting − Lack Of PenetrationTroubleshooting − Burn-Through Troubleshooting − Waviness Of Bead Troubleshooting − DistortionCommon MIG Shielding Gases Weld beadTroubleshooting Guide For Semiautomatic Welding Equipment OM-227 978 − Parts List Main AssemblyDia Part Dia Part Mkgs Description Quantity H-14 Gun 231Options Optional Drive RollsConsumables Page Work like a Pro Support ServiceAssistance Contact your Distributor for Hobart Welding Products