Mine is going to get two coats of epoxy primer with four or five coats of black semi gloss single stage urethane paint. Would love to have it powder coated, but because of price and location that's not going to happen.
I'm sure this reply will draw ire, BUT, every instance of POR15 (which stands for PAINT OVER RUST) on clean, bare steel I've personally seen, FAILS to adhere and peels over time. It simply doesn't seem to stick unless there is some rust present, which is what it was originally designed to do. I've also witnessed people applying multiple coats and it doesn't stick to itself either and will peel. It does better if it is sanded between coats, but what is the point of that ? may as well paint over it. POR15 is an excellent rust CONVERTER but if you've removed the rust there is no longer a need for a converter.
My preference for a blasted frame is powder coating. If that isn't an alternative, then an epoxy sealer/paint is next.
1947 Ford street rod frame going to powder coating.
All the suspension pieces went too. If I remember correctly, it cost around $700 for blasting and coating.
I love the glossy look and durability.
'62 Impala SS 409 TH350
'66 Chevelle SS 496 M20
'70 Chevelle SS 396 M20
'67 Camaro ss/rs 350 PG
'38 Chev coupe street rod
'54 Chev 210 2 door
'69 Chev C10
'89 Chev R3500 roll back
Depending upon finances, I would probably do the epoxy primer, like "DP-90" if I could.
You can spray that with a cheap $20 harbor freight paint gun, outside, on a quiet morning.
Zero-Rust is a good option as well, like you mentioned.
Lacking funds - There's nothing wrong with Daves suggestion of a high zinc primer and a spray can top coat. Eastwood has a nice "chassis black" in spray cans.
I went and power washed my frame gooood and then hit it with metal clean and shot it with some zero rust black, looks stockish .Laid down 2 coats and it is pretty tough also been on there a coupla years and still looks good total cost was about $60
NO NO it wasn't ,I sprayed it down with some prep and etch I found at home depot .Put some in a spray bottle full strength psray it on and let it sit for half a day, then power wash it off. I did this twice came out CLEAN plus it gave an etch for paint to adhere. I also pour some into a can and let my bolts soak or whatever and it knocks the rust right off. You need to rinse and dry asap or it will flash rust. A gallon of this stuff was like $12 or so bucks. Don't be an idiot this stuff is basically an acid proper protection is a must After this step I wiped it down with a wax grease remover then sprayed it