if there's any film left it wasn't done right, it must be immediately flushed thoroughly, and water doesn't inhibit rust, - soda blasting is really a paint removal technique, it doesn't remove corrosion and leaves too smooth a surface - most paint mfgrs will not honor any warranty if soda blasting was used, regardless if it was defective paint product, poor application, or sloppy soda blasting -
see hereBill