Gently scrub the rust spots with a wire brush or with 120-grit sandpaper. Wipe down the chair with a sponge dipped in soapy water, then rinse the chair with clean water. Dry the chair with a towel.
Rinse out the sponge with clean water. Apply a rust converter to the wire chair with the sponge, according to the package directions. It converts any rust you missed to iron tannate. Wash and dry the chair.
Take the chair outside or to a well-ventilated area. Spray the entire chair with a rust-inhibiting metal primer. Hold the can 8 to 10 inches from the chair and apply the primer in even, overlapping strokes. Let the primer dry.
Apply two coats of metal spray paint the same way you applied the primer. Let the first coat dry before applying the second. If you want to keep the metallic finish of the wire chair, use an oil-rubbed bronze or other metallic color.
Let the spray paint dry for 48 hours before using the chair.