TIG stands for Tungsten Inert Gas welding. Also called GTAW (Gas Tungsten Arc Welding) and Heliarc® which was Linde's trade name for the TIG process when it was introduced many years ago. The arc is started with a tungsten electrode shielded by inert gas and filler rod is fed into the weld puddle separately. A slower process than MIG, it produces a more precise weld and can be used at lower amperages for thinner metal and can be used on exotic metals. TIG does require quite a bit more time than MIG to learn. It is similar in technique to gas welding.

MIG is required by law and by insurance companies in many localities for structural repair of automotive frames. MIG is also much easier to learn and faster to weld. For doing other types of welding, like sheet metal, it can be a matter of personal preference. For an auto body repair shop or a novice welder, a MIG is a good, practical all-around welder.

After welding and if application is critical , solution annealing is preferable.

The internal structure of the fuselage is generally (from what I recall), a mixture of welded and riveted structure with the skin riveted onto the structure. It would be far too time consuming to weld the skin onto the structure, not to mention the costs involved if a weld is done incorrectly. Until an effective method of mass-producing aircraft is developed (Eclipse tried it and has so far failed), the tried and true method will continue to be used.

There is much to read on the web, including some great information at the Miller and Lincoln websites. They can give you a pretty great overview of TIG welding. But, as with many skills, it takes hands-on practice as well as study, to be successful.

If your fiance has ever welded with a gas torch, he might already have the skills he needs. Unlike a MIG welder, a TIG does not feed an electrified filler wire for you. You are in control of a separate heat source (the torch) that you must manipulate in order to melt the base metal together, while adding the filler by hand to the molten puddle you're creating. It's the same way a gas torch works, just with electricity, rather than gas, as the heat source.

The tricky part comes in learning how hot to make the puddle, how much heat to apply (with a foot or hand controller), and how to coordinate the filler at the same time. Quite often, TIG welding involves metals like aluminum or stainless, which have their own quirks that need to be considered. It's by no means impossible to learn all of this…and it can be a very valuable skill to have, often paying higher than MIG welding jobs.

If your fiance shows this prospective employer that he is a professional who takes pride in his work, has studied the subject, and is willing to learn, he may get his foot in the door and start down a new path on his welding career. I wish him the best. Study all you can, and if you know a buddy who is good with the Oxy-Acetylene torch, go visit him right away for some practice!

Best of Luck!

It takes awhile to get use to,