Dont know about sand blasting,but if you decide to sand blast, glass
beading  is now usually used in place of sand blasting.Dont know why. I
bought a glass beader at Harbor Freight($30).The one with a bead tank that
looks like a motorcycle gas tank. Glass beads are about $20 /25 pounds. It
will take the rust off. It is called a spot balster.You can be fairly
accurate with it. 90psi air pressure. Lots of work to do say a exhaust
manifold.Best for small areas.