Pinging rust with a blow torch
 

Has anyone used this technique? I had a friend in HS that stripped a 911 down to nothing and used a blowtorch to "pop" all the surface rust off of the car. He told me that rust just pops off like pop corn if you get it hot enough. I just had to ask because I think about it all the time whenever I've seen surface rust on a car.

Not an expert...but to a metalurgical point of view...it surely modify the internal structure of the metal and it's further resistance to rust...!

Wouldn't it warp the panels?

he never had a warped panel. I just thought it was an unusual way of de-rusting a car. Of course he had to go back and spot fill the areas because of the pock marks in the metal, but most places were underneath in behind fenders and such.

with enough tips, I'd rather do this than grind