I have been working for the past few days on sanding off the damn surface rust that cracked through 7 layers of paint on my 67 Camaro. Prep guy way back then shoulda been fired. I started with chemical strippers and after the arm burns and mess realized the easy way was my air grinder, 6 inch disks at 60 psi with 80 grit sanding disks... cuts like butter... liquid stripper cut 1 maybe 2 layers of paint at a time, but you still gotta sand after it's "stripped". Good luck.
I was gonna go with sand blasting, but heard too many horror stories of sheet metal warping from the heat, so I chickened out.