Example.
http://www.durgan.org/URL/?NFLUZ Rust proofing plant supports using Tremclad.
Periodically rebar and other metal plant supports are painted to reduce rusting. The supports are placed on a plastic sheet on a sunny day and brush painted using Tremclad paint. Any shade of green is ideal. The paint dries in about an hour. The rods are basically rolled over until the paint covers completely, using a brush. These spiral plant supports were also wiped longitudinally with paint while wearing rubber gloves. On rebar and other spirals, it has been found that the paint lasts for several years. These unpainted, six foot spirals were purchased in a dollar store.
I do this procedure with rebar, concrete reinforcing wire. The paint last for a long period, I have some for around ten years. The process only takes a few minutes. I find a brush is better and more economical than spraying from the small cans.