hi i recently bought a 1990 jayco pop up. among other things i need to fix it has a very rusty frame, not structural just surface rust. i will probably wire brush the tongue and rear bumper down close or to bare metal and repaint. but not sure about under the trailer. i was thinking maybe wire brush off the loose rust and use a product like stop rust or naval jelly(stuff that looks kind of like milk and turns black when dry) then paint over that. anyone here think thats a good/bad idea or have another great idea that i have not thought of. i would love to here some opinions on this since im not about to remove the frame and do a pro job.