Tungsten Inert Gas (TIG) welding is also called Gas Tungsten Arc Welding, or GTAW. Which is much more fun to say because it sounds like you’re an old man from Texas talking about his guitar. With that pronunciation firmly implanted in your head, let’s look at why getting your GTAW on is preferable for aluminium.
How TIG welding works
The Tungsten part of the TIG equation takes care of the heat required to weld. It sends an arc of electricity to the surface you’re welding. Meanwhile, the Inert Gas protects and cools your tungsten and the weld puddle. Argon is typically used and recommended for aluminium welding.
For aluminium welds, it is important to pre-clean the metal well before you start. Aluminium is a tricky metal. It forms an oxide layer on its surface that is invisible to the naked eye. Cleaning it will help remove at least some of this layer.
And this brings us nicely into why we prefer TIG welding for aluminium.
Why choose TIG welding for aluminium?
You can certainly weld aluminium with a MIG welder or oxy-acetylene torch. However, there are a number of advantages to going with TIG.
TIG welding removes surface oxides
You need to set your TIG welder to AC as this gives the electrode positive polarity and the metal surface negative polarity. Having the current flow from negative to positive terminals will “clean” the metal of oxides, exposing a fresh surface for welding.
The newer the material, the lower the oxide level is likely to be. However, even if you’re working with shiny new metal, there will still be at least some level of oxidation to contend with.
These oxides melt at a higher temperature than the base metal. And, since they aren’t visible, it can be hard to judge precisely the balance you’ll need. But you can get an idea based on the age of the material and how much exposure it’s had to the elements.
Once you’ve started, you should observe the puddle. You’re looking for it to be clean and shiny. If you’re getting a film or dark spots, you may need to drop the AC balance down to increase the cleaning action.
TIG welding is healthier for you and the environment
TIG welding is significantly cleaner and produces fewer sparks and air contaminants. This will be of benefit to you and your surrounding environment. Of course, PPE is still required. In accordance with Safe Work Australia’s Welding Guidelines, we recommend:
- Welding helmet (obviously);
- Leather welding gloves;
- Leather welding apron;
- Closed in shoes;
- Flame resistant clothing;
- For some jobs, a screen, hearing protection and/or a respirator may be necessary.
Basically, if children aren’t terrified of you, you’re not appropriately dressed for welding. If you’re interested in knowing more, click here for a comprehensive breakdown of the legal requirements for welding gear.
TIG welding provides superior strength and appearance
TIG welders are slow but precise and capable of a level of delicacy MIG welders just can’t achieve. They are versatile machines, capable of working with a variety of metals. But, as a general rule, the thinner the material you’re working with, the more imperative it is to use a GTAW.
As one welder told us:
“TIG is slow and pretty, MIG is fast and ugly.”
When you might consider MIG welding for aluminium
MIG welding will reduce your work time. It is easier to set-up and, with the welding wire fed automatically, the job gets done quicker. It is also cheaper. Consider MIG welding for aluminium if:
- you’re on a tight budget;
- you are inexperienced with TIG welding;
- the welds won’t be visible so you don’t care about appearances.