Addendum to cleaning, rust removal, and paint prep comments -- I now rely heavily on electrolytic rust and paint removal. Much, much easier and very environmentally friendly.
I invariably try one of my electrolytic tanks before resorting to other techniques. Small tanks are easy to make and use. For larger items, it'd be worth looking for and paying someone who has a larger tank.
Case in point: A painted, mildly rusted bracket for a wall mount bathroom sink, salvaged out of an old building. Cleaned the bracket with dish soap and water, wired it up, put it in the tank, turned on the power supply, and walked way to do other things while leaving it overnight. The next day, pulled it out of the tank, wiped off the old paint with a paper towel, and rinsed it off with clear water. It's ready to be painted, although I'm going to do a bit more prep, just to be sure, before powder coating it. (Need to decide what color powder to use ... leaning towards cobalt blue.)
