Rust conversion in practical use.

It is courses for horses. One nice way is to use galvanic rust removal. W here you have some electrolyte and use electricity to reduce the rust. Go od for things you can put in a container. Not so good in this case.
I just used a air powered needle gun to get all the thick rust off some she et metal and then painted it with aluminium paint. A better job would hav e had me use an acid to reduce the rust and then paint. I got some citric acid from Tractor Supply for that You can also get Naval Jelly from the au to parts store. It is phosphoric acid in a gel.
If you are reasonably close to Delaware, I have a stainless steel fertilize r spreader that I am about to get rid of.
Dan

Clean off the loose stuff and as much of the rest as you can. Then wipe it down with phosphoric acid. Let that work on it a bit, then wipe off any excess and neutralize the acid with some baking soda/water mix.
Now use a good primer to give it a good even coating. Now cover that with spray on bed liner coating. The spray can stuff is thin enough that it goes on smooth.

I got involved in a Honey Do. My wife uses a walk behind fertilizer spreader, she has taken very good care of it, washing off the corrosive fertilizer after each use. But the other day she pointed out some rust on the tubular frame and wants me to fix it before it gets worse. So, some areas are severely rusted (pitted) but most of it is still good paint. There is some peeling paint near the rust. Does anyone have a favorite RUST Converter. Should I sand blast the whole thing and start from scratch? Is there a favorite paint to hold up to the corrosive fertilizer. I have it completely disassembled, so I might as well do the best job I can. What is the best method to get her another 15 years out of this?
Mikek ============================================================
Assuming that it is still structurally sound I would go with POR15 epoxy paint. Never tried it but I can't imagine that fertilizer would affect it, and since I'm sure she stores the spreader inside when not in use I wouldn't even bother with the uv-resistant formula. Scrape or wire brush off any loose paint or flaking rust, leave the rest of the rust alone, wash with soap and water to degrease, dry well, and paint it. If you want a second coat, put it on 3-4 hours after the first coat, while it is still tacky. If you wait until if fully cures you will have to rough up the first surface to get a second coat to stick. I did the rear end on my car with two coats that way, and it still looks like the day I painted it 9 years ago. I bought the six-pack of tiny cans instead of one of the next bigger size (pint, I think) since the price was about the same ($30-35?) and I knew I would never use the rest of a bigger can before it cured in the can. I think I used one and a half of the tiny cans on the rear. I did put a sheet of saran wrap over the opened can, pushed down to touch the surface of the liquid, before I put the lid back on to try to seal it as well as I could. I think it worked ok, because I waited a couple of years before I had something else to paint and that half can was still good.

Does it handle manure?
If so we can put Crazy Eddy in it.

Excellent product - but even it works best on relatively rust free surfaces. I've been using it on the fender lips of my 21 year old Ford Ranger to keep the paint from peeling up the fender. I've got about half the small "starter can" left afterr five years of the Ranger - and I'd used a good portion of it for the earlier project I bought it for - can't remember what it was. I also use the saran wrap to keep it from gluing the lid on permanently, as well as sealing out all air and moisture and sealing in all the solvents. I clean the little artists brush I use for application with gasoline when I'm done (before the stuff dries hard on the brush!!)