Cleaning steel with water means that you'll have rust starting to form by the time you turn the sprayer off. Try to keep bare steel protected from moisture as much as reasonably possible.
Sandblast or glass bead, blow and wipe it all down and primer the same day. The primer is very porous, so you'll want to apply paint over the primer as soon as you can, once the primer is preped.
For a good looking and even application, consider spraying the primer and the paint.