Can a TIG welder give you an electric shock large enough to lift you off a wooden stool?

Hell yea! It depends on what you set the amps to and how well the person is grounded but a good shock from a TIG welder will definitely stand you up. Be careful though, crank the amps up to high and your dead. I've heard stories of guys getting zapped by relatively low voltage with a higher amperage, leaving work just as normal and then having a heart attack a few hours later. Electricity is not something to play with.