Before you check out the two pictures, let me explain.
I wanted to show my "bad" paint job, and explain why.
My bike is for exercise / fun and all I wanted to do was get rid of the rust and protect the metal. I also didn't want to add any extra layers that might hide future rust, or raise the time/cost of having the frame media blasted if I ever decide to do the job right.
Complete job cost around $12 for two rattle cans of paint, one auto primer, and one black engine paint.
Time involved was less than an hour of actual work. I didn't count the time between coats (4) as I was working on other projects.
All I did was grind off the rust and bubbled paint (hidden rust) with my Dremel A file could have done it just as fast and probably left a smother metal surface. Then blew off the dust, a quick wipe down with Goo Gone (it smells like lacquer thinner) followed by two coats of primer and two coats of black.
First picture is the worst part, the area that had the most rust, but as bad as that looks, seeing it from a distance (2nd pic), as those I pass will see it, the bike looks fine.