Speaking from experience over the past year....
I called the local hotrod shop and asked who they use to sandblast. I had the body blasted with the same folks they recommended and asked not to have them primer it.
When I got home, I went straight to Eastwood Epoxy Primer to make sure there wouldn't be any rust. I probably sprayed it a week after I got the body back. Can't say enough good things about the $16 purple spray gun at Harbor Freight for this.
Now a year later I'm putting finishing filler and paint on here's what I would have done differently...
1. Hit the whole body with 180 grit. Just knocks off the peaks in the metal left behind by the sandblasting
2. Do the sanding because you'll want to go over the whole thing with wax and grease remover or all prep. I didn't do this step and saw rust coming back in some of the pits. When I first tried doing this without sanding first, the peaks in the metal just tore my microfiber cloth apart leaving behind tiny fibers.
2. Air gun and shop vac EVERYWHERE. I am still finding media hiding in places haha
3. Don't sweat dust in the air or laying on primer perfectly. Just get it on there because you'll definitely be sanding every surface later multiple times before paint.
I've read differing opinions on what to do after primer, but I went with what two of my local body shops and one hot rod shop told me. Modern epoxy primer is ok to lay fiberglass filler over. but you can also do DTM if the metal is new and super clean. Over primer Just scuff the primer with 180 grit and away ya go. Modern filler like Evercoat Rage should also lay on primer because it is porous and may trap water between bare metal and the filler. I like to think I'm making a sandwich on top of the bare metal. Primer seals the metal for as long as I want to take doing filler and body work..primer/sealer is also at the end before color leaving all the body work sandwiched between two primer steps.
I've been happy with my research and results but had to "redo" some of the steps above at a later date.
