Many years ago I had good luck repainting rusty metal using naval jelly,
then primer, then enamel. Eight years ago I had good luck with POR 15,
but it was expenive.

I've read that Zero Rust is a cheaper paint and does a very good job.

I've also read that Picklex 20 is an excellent way to prepare a rusty
surface for painting. I've found only one source, which charges $31.50
a pint plus shipping.

Are Picklex 20 and Zero Rust the best ways to repaint rusty iron? Who
sells them?