TIG is a form of welding that is still quite popular among welders. There are many tips and tricks that can help make your welding jobs easier.
When welding aluminum on A/C power make sure that you do not use too much torch gas. It takes a lot of amperage to weld aluminum, even though the melting temperature is less than half what is required for steel. This is because aluminum conducts heat away from the weld puddle much quicker than you can put it in.
Use only the necessary amount of argon on the torch gas you use. If you use more than that, then everything you try to heat up will seem as if you are just blowing cold air on it. Too much argon will also make a loud and erratic arc because the force of the arc is too great. If you are trying to weld aluminum and are wondering why the arc is so loud, then you probably have too much argon.
Use the old school kind of collet body (not the gas lens) and use a cup that is one size smaller than what you would use for steel which will provide good shielding. The smaller TIG cup will confine the shielding gas to the puddle. This keeps arc energy from being wasted. When you are welding aluminum again, try using a #6 cup and turn the shielding gas flow to 12-15 cfh. You should find that the arc is much quieter.
Since we're discussing shielding gases, keep in mind that Argon is not the only one you can use for TIG welding. Argon is the most versatile and the most common one used. It normally gets the job done but sometimes mixing a little helium with the argon can make your job much easier. This is especially true if you happen to be using a small inverter TIG welder that has a limit of just 200 amps.
100% argon is the coolest gas and the most often used. It is often considered to be the best all around gas. A mixture of 75% argon and 25% helium can make a big difference in welding aluminum if it is thicker than .063". If the aluminum is thinner than that then using helium is unnecessary. If you are welding thick aluminum and magnesium then use a 50/50 mix of argon and helium. For thick aluminum castings use a mixture of 75% helium and 25% argon. This mixture welds cleaner than pure argon and puddles quickly. It can also be used for welding pure copper and bronze on DCEN. 100% helium is very hot but if you are using A/C power starting the arc is difficult.
Another good tip is to remember that no matter what kind of shielding gas you choose to use, the metal has to be clean. Stick and MIG welding is much more forgiving about dirty metal than TIG welding is. In order to have successful TIG welds, the metal has to have no scales, rust, paint or anything else. In other words, if you are welding rolled steel it must be ground into shiny metal, not simply polished to be bright.
Be careful of breezes when you are doing TIG welding. If there are drafts or windy conditions then you can lose the coverage of your shielding gases. This can lead to porosity and pinholes in the weld. If you know you will have to work in a drafty area then you will need to create wind breaks to avoid this problem because this kind of welding will not tolerate even a tiny breeze.
