Removing surface rust to repaint

[Mike's money pit]

Hi guys, I tried to search for old threads dealing with my questions but saw lots of different answers due to the variety of situations. I am in the process of buying this 1988 C1500. The silver paint on the roof is thin or missing, and the roof has a bit of surface rust. I’d like to sand the roof with a DA sander and 80 or 120 grit (if that is best for removing the paint and rust) and then repaint. What is the proper method to get the metal from its current condition to ready for epoxy?
Thank you,
Mike

[mongocanfly]

hit it with the da like you planned...don't overheat it or put to much pressure on it..let the sandpaper do the work for you...should be good

[Foot Stomper]

Don't remove any paint that's tightly adhered as there's no benefit, only harm.
Remove loose, flaking or otherwise unhealthy paint with da.
Solvent wipe and apply epoxy primer to bare steel.
Little specs of rust in the steel can be primed over with epoxy. Just make sure you have it sanded enough that you can't scrape any rust off.
Prep the rest of the roof, high build primer, then paint it.

[Mike's money pit]

Thank you for the replies. So my plan will be DA on the rusty areas specifically but I will only sand enough to get most of the rust. If there are a tiny pits I will leave that. The rest of the paint on the roof will only get sanded off if it is loose. I will make sure to scuff the whole roof with the DA. Then I will tape off and apply epoxy.