Hoo boy - got into the trim a bit. My plan was to sand all the rust off, leave the existing paint where it's still good, and paint over everything. You know how they say no plan survives first contact with the enemy? Or how, if you want to hear God laugh, tell him your plans? As I started sanding, I started seeing little "bubbles" emerge in places where the paint was seemingly intact. Sanding further, eventually these bubbles "pop" and reveal a tiny spec of rust underneath. What? The paint had appeared perfectly intact there before I started sanding. After I experienced several of these bubbles I determined to break out the paint stripper and get all the paint off just to see. Once I had the paint all off, it was flabbergasting to see all the tiny freckles of rust under what had been perfectly "intact" paint. Not sure if they were there before the metal was painted... or maybe somehow moisture and oxygen somehow actually penetrated through the paint to the surface below. No, these are not "rust through"... the metal is solid, just a tiny freckle of surface rust.
Well, that will never do boys and girls. I'm not going to the trouble of painting just to have to strip it all off AGAIN 5 years from now and re-do it when the rust starts to re-emerge. All the paint is going to have to come off and Cav, I am seriously looking into the "rust-converter" treatment thing... I haven't seen the brand you mentioned on the store shelves here but I'm looking into it. When it comes to stripping, sanding, priming and painting, I'd rather go to "too much trouble" than to have the "double trouble" of having to do it all over again in a few years. One and done. Probably going to take me an extra weekend now. Ah well.