Lay drop cloths down to catch paint chips and protect the surfaces from paint.
Wear rubber or latex gloves to protect your skin from the chemicals.
Mix the degreasing cleanser with water according to the manufacturer's directions. Wipe down the surfaces of the chairs with a rag soaked in the mixture, removing any dirt or oil from the surfaces. Rinse them with clean water, and allow them to dry.
Inspect the chairs for any areas of loose, blistering or bubbling paint. The metal chairs have probably taken a beating from the outdoor elements. Make a hole in any bubbling and blistering paint with the corner of the scraper. Using a wire brush, scrape back and forth with firm pressure, removing the loose paint. (The metal brush cannot hurt the stable metal underneath.) Outdoor metal chairs will often show signs of wear in the crevices and joints; scrape loose paint from these hard-to-reach areas with a metal file.
Smooth the surfaces by sanding back and forth with the steel wool, removing any visible demarcation.
Wipe the surfaces with the tack cloth to remove any specks of metal left on the surface of the chair, leaving a dust-free surface for a smooth paint application.
Apply a metal primer designed for rust and corrosion prevention to the chairs with a paintbrush, using smooth, even strokes. Use thin coats to prevent drip marks in the paint. Allow the paint to dry for six to eight hours.
With a clean paintbrush, apply rust-resistant paint to the chairs. Extreme How To says, most manufacturers indicate what type of paint you should use with a certain type of primer (see reference 1). If unsure, ask the paint expert in your hardware store. Allow the paint to dry for six to eight hours.
Apply a second coat of paint to give the metal chairs an even finish. Allow the paint to cure for three days before replacing any cushions on the chairs.