Rust can naturally occur on iron due to exposure to oxygen over a long period of time. Rust on an iron bed can be very unappealing and give an impression of poor cleanliness. Rusty iron is also weaker structurally than iron that isn't rusty. Rust appears very easily and frequently if the bed is not looked after properly. Use household vinegar to remove rust, and use petroleum jelly to prevent rust from appearing in the future.
Apply a generous amount of vinegar to a soft cloth. Scrub the rusty areas of the iron vigorously, re-applying vinegar to the cloth often. Allow the iron bed frame to soak in the vinegar for an hour. The vinegar will loosen the rust from the bed frame considerably.
Rinse the bed with water and scrub using steel wool. Repeat this process until the rust is removed and your iron is shiny.
Apply petroleum jelly to a paintbrush. Smear a thin layer of petroleum jelly to your iron bed, taking care to ensure application to the joints. Repeat this process annually to prevent rust from reappearing on your bed.