Sand and a few other medias will warp sheetmetal.
Personally the best media would be plastic. Plastic will not harm the metal, but it does NOT remove rust.
Most media blasters first use plastic to remove the paint then come back with glass beads and remove the rust.
I would NOT use soda.
I would have the truck media blasted, I think the cost greatly outweighs the time and effort thats involved in sanding. Also I would not send the entire truck to the blaster at once. Give him pieces,when you get them back you are not sitting on a complete truck thats in bare metal...Eric
