im gonna do the same thing as you to my "Rust-eS"s2,gettin as much rust away as poss,,then when shiny,coating straight away,with a metal cellulose primer,,not acrilic(water based),then gonna put some tetrosyl,,(drying type)black seal on,,(halfords sell it),,then a blast of stone chip gaurd,,hope you find a way yerself,,good luck..(ps im a painter by trade,the only real thing to stop rust as we know is new metal.)crimbo.