A decent sandblast job SHOULD get rid of current surface rust, at least, but won't stop it obviously. You will NEED to primer it ASAP since sandblasting takes everything down to bare metal. Also, depending on how aggressive your goin with this, the sandblasting could leave scores in the metal so you might need to do some bondoin or at the very least hours of sanding bare metal with a finer and finer grit. If you have good paint and are just wanting to repaint it then it'd be much more economical and time-effective to get some 400-550 grit sandpaper and just rough your good paint up. I'm in no way saying sandblasting should be avoided, it definitely has its uses. But as the good saying goes, make everything as simple as possible (but not any simpler).