1. Clean the area to be welded thoroughly. Cleanliness cannot be stressed enough. It’s not like MIG or stick welding where you can get away with welding over a bit of rubbishy or unclean metal. Try to TIG weld over rust, paint, or heavy oxide and you will contaminate the tungsten electrode and the weld pool.
2. How much should the tungsten electrode stick out? As a rule of thumb, stick-out should be half the diameter of the nozzle orifice. I always add a couple of millimetres, so I can see more easily.
3. What level of argon gas flow should you use? With low amps and material up to 6mm thick, start at a flow rate of 8-10 litres per minute. Use a higher flow for bigger amps and heavier material.
4. Use argon gas only, not the argon mixes commonly used in MIG welding.
5. Which tungsten types should you use for the electrode? Thoriated, ceriated, or lanthanated for DC, and zirconiated for AC aluminium
6. To set up and test that the settings of your machine are correct, try welding some scrap metal first. You don’t want to blow a hole in something you want to keep.
7. Feed the filler rod into the weld pool. Many learners will shove it into the arc and hope for the best. Not so! Just dip the wire into the leading edge of the weld pool. That’s where your concentration should be.
• Clean: Make sure that the weld joint area and also the filler rod are as clean as possible. This is an important preparation. Remove all oil, grease, paint, rust, and dirt. Contaminants such as these may result in arc instability, contaminated welds, or contaminated tungsten.
• Clamping: Clamping may be needed if the work piece cannot be held during tacking or welding. Remember you need both hands for TIG welding.
• Tack welds: On thin materials, it is a good idea to make short 2-3mm tack welds close together, as the heat will distort the joint as it is being welded.
Hold the TIG torch in your hand at a 70°or 80° angle. Make sure that the tungsten is off the metal by approximately 3-6mm. Don’t let the tungsten touch the work piece at this stage. With a gentle backward scratching motion, strike the tungsten onto the earthed material to be welded. A weld pool will start forming. From here start moving forward at a regular speed. You will soon see what speed suits your amperage.
Now you can try using a TIG filler rod. Hold your filler rod lightly in your opposite hand so that it rests horizontally at about a 15° angle from the material. Wait for the molten pool to form on the base metal and gently dip the filler rod into the weld pool. As you move forward, you will see the weld bead starting to form. If your machine has a high-frequency start, there is no need to touch the parent metal.