Wash down the surface of painted metal furniture with a heavy-duty detergent and warm water. Scrub with a soft-bristled brush, using care to get into cracks and grooves.
Rinse to remove dirt and grime, and to wash away soapy residue. Soap can make furniture sticky, which can act as a magnet for dust.
Place the cleaned furniture in a sunny area and allow to air dry.
Apply two thin coats of car wax to painted metal furniture to protect the surface and give it a shine. Car wax also prevents scratches and repels dust and dirt. Follow the manufacturer's instructions for applying the wax.
Wash garden furniture with a solution of white vinegar and water to remove dirt and grime, and to inhibit mold growth. Mix 2 cups of white vinegar and 2 tablespoons of dish detergent to a gallon of warm water.
Apply to the furniture with a soft cloth or sponge to cover the surface of the furniture. Use care to cover creases and crevices where mold and residue tend to build up.
Scrub with a medium-bristle brush to remove surface residue. Use care to get between cracks, grooves in straps, seat pads and umbrella fabric.
Rinse with cool water and allow to air dry.