Refinish the Iron You Have, or Start Again?
Refinishing is the cheaper answer, and on most Tempe fences it is the right one as well. Steel is thick, and rust sitting on the outside of a picket is a long way from rust that has gone through it.
The decision has little to do with how bad it looks from the street. Orange staining looks alarming and is usually shallow. What matters is whether the steel still has its thickness, and the only way to know is to get down at the base of the fence and check.
When a fresh finish is the whole job
Where the metal is sound, this is a finishing job rather than a fencing job. The rust comes back to clean steel, the bare metal is treated and primed so it cannot start again from underneath, and a new coat goes over the top. The run comes back looking like the week it went in.
Color is worth a minute. A refinish is your chance to keep the shade you have or change the whole run at once so it answers to your house.
The other thing that gets sorted is the reason it happened. If a sprinkler head throws water at the fence line every morning, turning it a few degrees costs nothing and buys years. That advice is free whether we do the work or not.
When a stretch is better off replaced
Sometimes the steel really has gone. If the bottom of a picket has opened up, flaked into layers, or gives when you press a screwdriver into it, no coating will bring it back. Covering it hides the problem for a season.
The useful thing about iron is that it comes apart in pieces. A run is panels and posts, so a bad stretch lifts out and a new one goes in without touching the rest of the fence. New panels get matched to the existing pattern and picket spacing as closely as current stock allows, and the whole run is finished in one color, which is what stops a repair reading as a patch from the street.
Gates are their own conversation, because a gate carries weight the fence never does. Hinges, latches and the post holding it up wear out long before the gate itself. Gate repair covers gates that drag, stick or will not latch.