Buying a Tig Welder & Taking a Class**

The rod should never make contact with the tungsten. If it is, you're either sticking the tungsten in the weld puddle, or hitting the tungsten with the filler rod when you try to add filler material.
Sounds like a good deal MadDart. Not to put any damper on it, but with 250 amps, you're no where near welding 3/4" material. Figure as a basic guideline, 1 amp for every .001" of material. The 250 amps could probably safely do 3/8" steel, and 1/4" aluminum(probably with some helium for shielding gas). Keep us posted on how its coming along...remember, practice is what makes a good welder. Stick with it.