Restoration and rusty metal

Want to paint the 4000. I have been sanding for 2 days and will never get all the rust off. What do you guys use before painting? Does Rustolum Rust Reformer work? Or is there something better? I just want to stop the oxidation so the rust doesn't bleed through the new paint. Spray would be nice but I can brush it on too.

I have used Rustolum rusty metal primer with good results.

Ospho phosphoric acid prep is what I use, it's green and watery, turns the rust black AND it's supposed to be a primer too. Watch if you're using epoxy primer though, they don't play well together and a pressure washer will lift it - ask me how I know...

Used as a base with enamel and it works great!

I'm restoring a Ford 671, a ford 501 pitman mower, and an old 3 point blade. I've mainly worked on the blade and the sickle mower so far. I've only done the light housings (new bulbs after the 12 volt conversion), the seat, and the grill (had to take out some dents). I've sanded everything down as best I could and then sealed it all with the Rustoleum rust converter (a couple nice heavy coats) and I'm super happy with the results. I started with the face of the blade because I knew it wouldn't need to look perfect. I went over it with the sander a few times, then put on a thick coat and went to bed for the night. I came back the next morning and the surface looked a lot smoother and more paintable than I remembered the night before. Gave it another light sanding as well as finishing the sanding on the rest of the blade and gave everything 2 coats that day. The following weekend, I put on primer, then painted the blade a couple of coats of hardened ford grey and ford red(orange) to match my tractor. Everything looks great. If you do a good job of prepping the surface and then sanding it just like you would a good paint job, it seems to turn out real nice with the rust converter. Hope it holds up long term. On the sickle it was a little tougher to do a good job with the sander, but I'm real happy with the way the converter handled the rougher spots. I'm finishing the mower this weekend and will post pictures when I'm done.

I can only tell you what me and my son have done to address rust in cars and tractors. First, sand until you have a fairly sufficient, solid metal surface. Then, go to the True Value hardware store and get a bottle of rust converter. Use the converter all over, including all exposed, non rusted metal surfaces. Then, spray all of it with an etching primer. Then, spray all of it with a good primer (not etching primer). Then , top coat all.

From my experience with rust bubbling up from where rust pits were prior to professionally prepped work, I am a strong believer in watery thin rust converter, usually after sand blasting. If it isn't watery thin It can look really good for a couple years, then the rust will be bubbling up. There was recently an add in the local CL for a '65 Mustang for sale. Seller stated that there were three places where rust was bubbling under the six year old paint. Those few bubbles reduces the value of his car by the price of a complete prep and paint job.