9 Rules Of Thumb for Successful TIG Welding

Date: 05-08-2025
Weldclass Academy

 

In the world of welding, some of the most useful tips aren’t found in manuals, they’re learned on the job, passed down by experienced tradies, or discovered the hard way. When it comes to TIG welding in particular, there are a few simple hacks that can make life a lot easier, especially for those starting out.

Here we share nine "rules of thumb" from Weldclass' Marketing Manager, Andrew Barnes. Andrew is Australia's first Bronze Medal winner, former Australian National Judge, and former International Chief Judge of the WorldSkills International Welding Competition.

 

1. Set Gas Flow Based on Nozzle Size

Match your shielding gas flow rate to the internal diameter of your gas nozzle.

Rule of thumb: 1 LPM of gas per 1mm of nozzle ID.

Example: A 12.7mm nozzle = approx. 13 LPM of gas.

 

2. Tungsten Stick-Out Should Match Nozzle ID (When Using a Gas Lens)

With a gas lens, your tungsten stick-out should equal the nozzle’s inside diameter.

Example: Using a 25mm nozzle? Your tungsten stick-out should also be ~25mm.

 

3. Set Correct Post-Flow Time

Protect your tungsten with adequate post-flow gas. 

Rule of thumb: If your machine has post-gas time control, adjust this to 5 seconds of post-flow for every 1mm of tungsten diameter.

Example: A 2.4mm tungsten = 5 x 2.4 = 12 seconds of post-flow.

 

4. Practice the Right Welds First

Build your TIG skills step by step:

  • Start with straight beads on plate

  • Move on to pad welds

  • Finish with T-joint fillet welds (great for developing control)

 

5. Don’t Weld From a Distance

Maintain a close working position. Your face shield should be 150–200mm from the arc for best visibility and control.

 

6. Double the Gas on Open Stainless Corners

When DC-TIG welding open outside corner joints on stainless steel, double your gas flow. This ensures proper shielding and helps prevent oxidation.

 

7. Know Your Amperage for Steel

Rule of thumb: 25 Amps per 1mm of material thickness.

Example: Welding 3mm steel plate = 3 x 25 = Set current to around 75 Amps.

 

8. Use More Amps for Aluminium

Aluminium needs more heat.

Rule of thumb: 35 Amps per 1mm of material thickness.

Example: 3mm aluminium = 3 x 35 = approx. 105 Amps.

 

9. Watch the Weld Colour

Colour is a key quality indicator:

  • Clean weld: Shiny silver or gold

  • Bad weld: Black or grey (likely means poor gas shielding)

 

 

More TIG Welding Articles:

The TIG welding process - your questions answered

TIG Parts Explained - What goes where on a TIG welding torch

All TIG Articles

 

 

Tags
TIG Welding