Chemical gets ALL the paint, filler, seam sealer, etc.. It then gets ALL the rust. Some places offer a zinc dip as well which then coats to prevent future rust.

Blasting of any sort only gets what the blaster sees or hits. As well, there is NO blast media fine enough to get all rust (fine pores) and therefore without some sort of chemical treatment afterwards its just bound to come back.

There will be naysayers and skeptics of both processes, it all boils down to personal preference.

I have had stuff blasted and I have had stuff dipped. The dip was far more impressive, leaving the surface as it came out of the stamping dies.

The downside to dipping of course it that it removes all the interior sound deadener, so you have to consider what you'll do about that.

Lately the big boys in the business seem to be going with the dip.