All the rust is gone, I must have spent as much time on the silly concave weld spots in the window sills and the rain gutters as I did on the entire roof, but I tell you you can snort cocaine out of 'em, jk.
Having gone through all this trial and error, I don't think I could have done it with one method or a single medium. In my case it took two to Tango, the Phosphoric acid ($15) from Home Depot and the wire wheels ($10) for the angle grinder/drill. So acid to do the heavy lifting and abrasives to get into those tough to get to spots nooks and cranies. Yes steel wool and paper towels get honorable mention as well!
Wait till you see how I primered it.
