Painting metal lockers requires cleaning them thoroughly and priming them before painting them. Metal lockers can also be finished with specialty paint, numbers or decals.
First, scrub the locker clean of any dirt or rust. It may be necessary to use steel wool to remove significant rust spots. Next, sand and prime the metal surface. Prime the locker with a rust protector since it is metal. Some paints have a built-in primer, but metal lockers need protection from rust, especially if they are located outdoors.
If using spray paint, drape the area within an 8-foot radius to protect surrounding objects. Ensure that the area is well-ventilated and covered. Use a roller brush to create texture, or spray paint to give a smooth, factory finished look. Either way, tape the handles to avoid getting paint splatter on them. In addition, open and close the door while the paint is drying so the paint doesn't gum up the hinges.
Give the lockers at least 24 hours to dry. Then finishing touches can be added. One option is to weather the paint with wax and craft paint applied with a sponge. Another option is to utilize stencils and spray paint to create shapes or letters.