If you are tired of the appearance of dark wrought-iron bed frames, you can paint them in the hue of your choice. Not just any paint will do, though. Metal paints contain additives that prevent rust. Also, not all metal primers and paints are compatible. One solution is to choose a primer and a finish-coat paint from the same manufacturer that are designed to be used together.
Wipe the wrought-iron bed frames with a rag that was dipped in mineral spirits. That will help you to remove all traces of oil and grease from the frames.
Scrape rusty areas with a putty knife or scraping tool. Remove all loose rust scale. Rub the surface with steel wool, too.
Apply an oil-based primer. The primer needs to be designed for use on metal surfaces such as wrought iron. Roll on the primer with a small roller. Spread the primer with a paintbrush. Cover the whole surface with one coat of primer.
Paint the bed frames with a finish paint that has a rust inhibitor within 24 hours of priming them. That will help the primer and paint bond.
Roll on the paint in the same way you applied the primer. Use a paintbrush to make smooth, sweeping strokes to distribute the paint. Switch to a paintbrush with synthetic bristles if you decide to use a water-based paint.
Clean oil-paint paintbrushes by swishing them in several changes of fresh mineral spirits. Use soap and water to remove water-based paints from synthetic bristles.