DA sand it with 80 grit to get to the bare metal. Then use 180 to take out all the 80 grit scratches. Start with one fender, get it sanded to metal then get two coats of Epoxy Primer on it before surface rust starts.
Then start the next item. Again as soon as you get it stripped, get some Epoxy Primer on it.
After you get everything stripped and epoxied, you can start with the body work. You can apply the "bondo" right on top of the epoxy primer.
Again work one panel at a time. One door, one fender, hood and etc. After you get a panel worked and you're satisfied with the look, spray a coat or two of Epoxy Primer/sealer on it. You don't have to sand the Epoxy Primer/sealer when you go to apply your base coat.
What kind of paint are you planning to use. Base Coat/Clear Coat (BC/CC) or Single Stage (SS).
