Gas tungsten arc welding (GTAW), also known as tungsten inert gas (TIG) welding, is an arc welding process that uses a non-consumable tungsten electrode to produce the weld. The weld area is protected from atmospheric contamination by an inert shielding gas (argon or helium), and a filler metal is normally used, though some welds, known as autogenous welds, do not require it.
In motorsports fabrication this is the primary method of welding, and in our shop is the only method of welding. We can weld various types of materials using this process, such as 4130 chromoly plate and tube (suspension components and chassis), stainless steel (headers and exhaust), aluminum (body panels and such), and titanium (light weight bolt on parts).
Tig welding is an art form to say the least. It takes years and years of continuous practice and most of all patience. I think the beauty of tig welding is that there are so many different techniques on how to flow a puddle, and there is a purpose for just about every technique.
Not a lot of shops will utilize tig welding as there primary source of welding simply because it takes too long. I would say it takes 3-4 times longer to produce a puddle than a mig weld. However the actual welding portion is not what detours people. It is the material preperation as well as the positioning. To prep a joint for welding, the tube needs to be to bright shinny metal (inside and out) and wiped clean with acetone. This sounds easy but this may require removing mill scale, rust, grease and grime, ext., which in turn takes time. Depending on the thickness of material you may need to run multiple passes in order to get a good quality sound weld. And then there’s position. Tig welding is all about position. If you are out of position, then maintaining torch angle and speed consistancy is a real challenge. Try to get in the most comfortable position as possible at all times, this may require rolling your project around on the garage floor.
If you ask 10 different welders in the business for advice on puddle techniques, you will get 10 different answers. Do not let that discourage you from attempting to master the art. I feel it is imperative to try everything and try to master everything. It will only make you better in the long run.