TIG welding (Tungsten Inert Gas welding) is a type of welding that is ideally suited to tricky shapes like curves and corners. It offers precision, accuracy, and quality – and a great appearance when done correctly.
TIG welding is used in a wide variety of applications and industries. It is commonly used in the building of aircraft, ships, and other vehicles, particularly in pipework and sheet metal. The process can be carried out in tight spaces and so is often performed ‘in the field’ as well as in workshops. With such a visually pleasing appearance, TIG welding is also used in architectural work and art.
It’s not the easiest type of welding to master so it’s not the best place to start if you’re completely new to welding. If you have some experience under your belt though, TIG welding is well worth getting into. It’s versatile, highly skilled, and immensely rewarding.
Ready to get started with TIG welding?
How is TIG welding different?
So what makes TIG so difficult to learn?
There’s a lot to think about: there are tons of settings to choose from and you’ll probably need to use a foot pedal to control the current while holding the torch and feeding the filler rod. You’ll also have very little room for error with your arc length, and the tungsten electrode cannot touch the workpiece.
Phew! Let’s break it down.
TIG uses a non-consumable, pointed tungsten electrode to deliver the electric current. The pointed electrode creates a small, intense arc that allows for greater precision. It’s also more difficult to control, so it takes some practice to get used to – especially as the arc must be kept a specific length for the correct results. On top of that, the tungsten cannot touch the work surface, or else it will get contaminated and need grinding.
Many TIG welding machines allow the current to be controlled via a remote foot pedal. During the weld, the current can be increased or decreased with the pedal to create more or less heat, similar to the gas pedal in a car. This allows for a huge amount of control throughout the weld. In addition, there are many settings that can be adjusted on the TIG welding machine.
To put it simply, there’s a lot of coordination and dexterity involved.
Don’t be put off though! A filler material is optional, so you don’t need to worry about that, to begin with. And if you’re comfortable with other types of welding, TIG will be easier to pick up. It’s all about practice, practice, practice.
What you need to TIG weld
As well as practicing, you also need to get familiar and comfortable with the different settings on the TIG welding machine, and what they do. We won’t cover them all here, the main thing to think about is the current.
Power
A TIG welding machine can operate on an AC or DC current. For welding steels, a DC current should be used. For alloys, use AC.
The base current is set on the machine and remains constant. TIG welding machines allow you to build up to the base current, which is useful for preventing the thermal shock of the workpiece.
To achieve a soft start, a foot pedal can be used or a minimum current can be set on the machine. When the arc is started, the current will increase from the minimum to the base current, over a time period which can also be set. The same can be applied in reverse when the weld is complete.
A pulse amperage can also be set if the application requires it.
The squarewave balance can be adjusted if you need to achieve greater penetration or cleaning.
Equipment
Electrodes – there are several varieties of tungsten electrodes. Different sizes and coatings are available to suit different power supplies, base metals, and applications.
Filler rods -also known as TIG rods, filler rods come in various materials like aluminum, steel, and nickel. The base metal will determine the filler metal and thickness of the rod.
Ceramic cups – a ceramic cup shrouds the tungsten electrode to control the gas flow. Different sized cups are available for different applications. Don’t underestimate the difference a different cup can make!
Shielding gas – argon and helium are the most commonly used shielding gases, though several mixtures and combinations of the two are also available.
TIG grinding wheel – for reshaping tungsten after it has been contaminated, such as by touching the workpiece.
You’ll also need the usual welding protective equipment:
- Welding helmet and eye protection
- Welding apron
- Welding gloves
- Protective clothing, such as a leather jacket
- Protective boots
Remember: safety always comes first!
As well as all the physical things you need to get started with TIG welding, you’ll also need plenty of patience, determination, and a willingness to learn. It’s tough and challenging. You will make mistakes and that’s okay – just learn from them!
Getting started with TIG
“Work on controlling your arc length and getting comfortable with it. The rest will then follow easier.”
When you’re just starting out TIG welding, it’s best to start off with thicker steel. The weld puddle is larger and easier to control, giving you more opportunity to improve your technique. Avoid using filler for now – just focus on keeping the arc length tight.
Most beginners hold the tungsten too far away from the workpiece for fear of touching it, which makes the arc too long. The problem with a long arc is that it draws more power from the machine and thus creates more heat, which can affect the quality of the weld or damage the workpiece. It’s also more difficult to control – the last thing you need when you’re just starting out! So: work on controlling your arc length and getting comfortable with it. The rest will then follow easier.
To make controlling the arc easier, your seating position is also important. Before you start welding, get comfortable. When you’re sat down, only use the table for positioning; you shouldn’t be leaning or bearing any bodyweight on your arms. Keeping your muscles relaxed will help you control the torch. The torch should be held at an angle to encourage the weld pool to form in front, 3 to 6 millimeters away from the workpiece (depending on the thickness) to achieve the correct arc.
Have a dry run with the torch across the workpiece first, to ensure the angle and speed feels natural. Make sure there’s nothing that will get in the way of the weld – or you – as you move. Try wrapping the torch lead around your arm to prevent it from snagging.
Attach an earthing cable from the workpiece to the welding machine. If you can’t clamp the workpiece, place it on a piece of sheet metal or clamp the workbench.
Get the weld started. The gas shroud will come first (for the time set on the machine) and the minimum amperage set on the machine will travel to the torch head. The arc will begin to heat and melt the metal, creating the weld pool.
Now, move the torch and push the pool along. Thinner metals, especially aluminum, will heat up as the weld progresses, so the travel speed will need to be increased to avoid excessive melt through.
At the end of the weld, reduce the amperage slowly for a soft finish. The gas should also flow for a few seconds after the current has stopped to allow the weld to cool.
Now, ready to do it again?
YesWelder tips for a successful start to TIG
Troubleshooting tips
Make sure your welding area is well lit. It will give you a better view of the torch and filler angle before starting the weld.
If you have trouble getting the arc started, it could be because the minimum amps are set too low.
If the workpiece is warping, you may have held the torch stationary for too long. It could also be that the amps are set too high, or that the workpiece isn’t held in place securely enough. If the clamp is already tight, consider tack welding the workpiece to another piece of metal.
If the metal starts to burn or melt away, there is too much current being fed to the weld pool.
If the metal has a flaky look to it, the current is too low.
Don’t hide the weld behind the gas shroud. Keep a good view of the weld pool.
Having trouble with the motion or movement? Try switching hands – you won’t necessarily perform the best with the torch in your dominant hand. The ability to use both hands for either task is really beneficial, especially if you want to get welding outside a workshop environment.
