You could always use electrolysis it gets rid of all the rust then all you have to do is brush it to get the deposits off and voila no rust at all, but you do have to paint right away or flash rust will happen. All you have to do is get a tub of water put some baking soda in it get a car charger, hook up a wire to the piece you want to get rust free, dip it in the water keeping the charger clamp out of the water, then get a iron rebar or something metal stick it into the water, make sure they aren't touching. Leave it in for a few hours depending on size of the piece you want rust free, brush off, paint, Good as new.
You can see lots of cool videos on youtube about it, just search Electrolysis rust removal.
Edit: also forgot to mention it takes off all the grime and existing paint as well so its like media blasting but not abrasive and works well on smaller parts.