I'm confused, how did you paint it and leave the rusty spots?
that's the easiest. I sanded the big hunks off with 80. washed it and scrubbed with a scothbrite pad. then grabbed a big jar of Vaseline, dipped my finger in and got a blob on my finger and dabbed it on the rust I wanted exposed, painted it with satin paint, let it sit a day or two. wiped the Vaseline off and waalaa there it is.
much easier to dip in the Vaseline and use the big tail that hangs off your finger and lay that down where you want it. -- a terrible messy job to do. get A LOT of rags if your going to do it and throw them away. I ruined a bunch of good rags and wasn't about to use the wash machine to eash them. Vaseline is tough stuff. it fights back when you try to wash it.
I used two different yellows a little here and there. and the orange didn't like the yellow so if I went over the wet yellows I got a little reaction and that worked out nice.