Once rust begins to eat holes in your metal patio chairs, particularly on their weight-bearing legs, then it’s probably time to buy a new set. Your chairs may be salvageable, however, when the holes are simply decorative — a hole at the armrest, for instance. In that case, you can repair and restore the chairs with a couple hours and some elbow grease. You can purchase everything you need in your regional home and garden centre.
Dissolve 1 cup of oxygen bleach in enough hot tap water to fill a 2-gallon bucket about two-thirds full. Wash out the chairs with the option and a scrub brush, then scrub the rusty areas with a wire brush or a rotary tool equipped with an abrasive brush, removing as much of the surface rust as possible. Let the chairs dry completely.
Place the chairs onto a drop cloth. Sand the chairs with medium-grit sandpaper, using an oscillating tool for large, flat areas along with a rotary tool for densely populated areas. Focus on the rusty places, but sand the whole surface. Once you are finished sanding with medium-grit, sand them with fine-grit sandpaper.
Wipe the sanding dust from the chairs with a slightly damp microfiber cloth.
Apply the metal patch and fill chemical to the holes and scrape it level with a putty knife. Let the chemical dry as directed by the manufacturer.
Sand the patched areas with the oscillating or rotary tools, initially with the medium-grit, then with all the fine-grit sandpaper, until the stains are completely flush with the surface. Wipe away the dust.
Shake the can of spray paint for one full minute. Spray the paint evenly onto the chairs. After 24 hours, then spray a second coat. Allow the chairs to dry the following 24 hours before using them.