Create a mixture of 1/2 cup water and 1/4 cup white vinegar. Stir the ingredients and dampen a plastic scrub brush with the mixture.
Wipe down the faucet with the mixture to remove any dirt, grime and soap scum, using slight pressure to remove any difficult stains. Dampen a soft cloth with plain water and use it to wipe away any loosened dirt and soap scum.
Rub the faucet with fine-grit sandpaper. The idea is to roughen up the surface, which allows the primer and paint to adhere more effectively. Wipe away the resulting sanding dust with a tack cloth.
Mask the sink, wall and any other areas you don’t want exposed to the paint with heavy paper and painter’s tape. Slip on a pair of rubber gloves, a dust mask and safety goggles before covering the faucet with a thin coating of spray primer designed for use on metal. Shake the can for at least 30 seconds and, holding it approximately 10 inches away from the faucet, cover the piece using even back-and-forth motions.
Allow the primer to set for at least three hours, or according to the package directions, before covering the faucet with the first coating of oil-rubbed spray paint. Once again, shake the can for at least 30 seconds and cover the faucet using even back-and-forth motions.
Allow the first layer of paint to dry and examine the piece. If the desired depth of color is not achieved, apply a second thin coat of the spray paint. Continue to apply additional coats, allowing each to dry completely between applications, until the desired color is reached.