Brazing is easy. I use an acetylene torch, though. Mapp gas has its application, but I prefer oxy/acetylene since I have it. Brazing does not make a strong repair, the repair being only as strong as the brass. Silver solder is stronger, but silver solder gives me grief trying to use it. I think I have the wrong flux for it.

I have used both TIG and MIG. You can do a great deal with TIG. MIG is also great, but both require very clean metal and work environments. Building new chassis braces would be a great application for MIG. You have to be protected from wind when you use either or the gas shield is blown away. The gas used for the shield has to be correct for the material you are welding. MIG does not penetrate as well as an arc welder. When that nasty old manure spreader comes into the shop for repair you had better just get out the arc welder and use good old 6011C rod. Body shops use MIG a lot today because the wleding can be done quickly with no distortion. By the time you get the sheet metal hot enough to weld with oxy/acetylene, the metal can/will distort depending on what you are working on.

Fortunately I didn't have to learn about cars be wrecking them. So far I haven't wrecked one yet, but I have been hit bad several times. Their insurance has always paid for my car.