MIG Torch FAQs
Straight answers to the questions people ask most when choosing and looking after a MIG torch.
Should I choose an air-cooled or water-cooled MIG torch?
Air-cooled torches are simpler, lighter and need nothing extra, so they suit most light to medium work and welds done in short bursts. Water-cooled torches have a coolant circuit running through them, which lets them carry higher currents for longer without overheating. They are the usual choice for heavy, continuous or production welding, but they need a water cooler and a little more looking after.
If you mostly weld at moderate current in short runs, air-cooled is normally all you need.
What do the numbers in a MIG torch's name mean?
The number is the torch's size class and gives a rough idea of the current it can carry, in amps. The real rating depends on the shielding gas and on how long you weld without a break, so it can be lower than the headline number suggests.
Always check the maker's rating for the gas and the duty cycle you will actually use, and choose a torch rated comfortably above the current you plan to weld at.
Which parts of a MIG torch wear out, and how do I know when to replace them?
The parts that wear are the contact tip, the gas nozzle, the diffuser and the liner. A worn or oversized contact tip, or a dirty or kinked liner, causes erratic wire feed, the wire burning back into the tip and an unsteady arc. Spatter building up in the nozzle upsets the gas shield and can cause porosity in the weld.
Change the contact tip when the hole wears oval or the arc becomes unstable, clean or replace the nozzle when spatter builds up, and replace the liner if the wire no longer feeds smoothly.
What length of MIG torch should I choose?
Choose the shortest cable that still lets you reach the work comfortably. A longer cable gives more freedom to move, but the wire has further to travel and more friction to overcome, which can cause feeding problems, especially with soft wires such as aluminium.
Most general fabrication is comfortable with a torch a few metres long. For long reaches, a wire feeder that you can move close to the work usually works better than a very long torch.