Calling all welders

[kamaroman68]

So I took a couple of extremely basic welding classes that the Snap On dealer puts on on a weekly basis. The teacher said many things some of which I didn't know some of which I thought was downright wrong. Anyways to the question. The teacher said that mig welding is the strongest from of welding. Stronger than tig stronger than arc welding. Is this true? If so why do people still make there rollcages with tig welds rather than mig? He also said that nascar uses mig welding although from what I see they all look tig welded. Come september I will be taking actual classes from the local boces. They start on basic arc welding moving into mig. The next class continues mig and starts tig. Thanks Chris