Chipped painted can be fixed by filling in the chip with wood putty or acrylic latex filler, sanding it smooth, then painting it.

Remove all loose, peeling paint down to the bare metal. Clean the exposed metal of any contaminants, such as dirt, oil, etc., and treat them with an etching liquid. Be sure to wear long sleeves and gloves to protect your arms and hands. Rinse the surface with clean water. Allow to dry. Apply a galvanized metal primer.

A natural way to remove paint from metal surfaces is to combine baking soda and water or white vinegar and water over a heat source. You can do this on your stovetop with a disposable pot or pan. For every quart of water, add 1/4 cup of baking soda or vinegar and bring the water to a boil.