MIG Welding aluminium is slightly different to MIG welding mild steel as aluminium has different welding properties. When welding aluminium it is important that the following issues are addressed with your MIG welder.

  • Firstly: ensure you have a MIG welder that is suitable for welding aluminium most copper transformer and newer inverter style MIG welders can perform this task
  • Secondly: Aluminium expands proportionately more when heated compared to steel and to prevent binding within the liner leading to the MIG torch the steel liner used for welding steel should be replaced with a Teflon liner of the appropriate size for the aluminium MIG wire you are using
  • Thirdly: For the same reason as the above point the contact tip needs to be bigger than the wire diameter as the aluminium MIG welding wire expands when heated. Rule of thumb is to use a contact tip that is two sizes bigger than the wire being used ie if using 0.8mm MIG wire a MIG contact tip of 1.0mm would be required
  • Fourth: Last but not least on the changes required for MIG welding aluminium is the shielding gas needs to be changed to Argon Gas
  • After making all the necessary changes to your MIG welder set up you are ready to MIG weld that aluminium welding project. Remember to keep in mind Aluminium is a great conductor of heat and soaks up a lot of your MIG machines capacity in dispersed heat and you will only get approximately half the relative penetration of weld compared to the same current(output)settings as those for steel

    Safety Tip
    remember aluminium when hot does not look hot and always be cautious when handling freshly welded aluminium as it can look deceptively cold