Originally designed to remove rust on Navy ships during World War II, naval jelly can also get the rust off your valued metal objects. The gel-like cleanser contains phosphoric acid, a chemical that interacts with rust, turning it into water-soluble iron phosphate that you can easily wipe off. Naval jelly works effectively on various metal objects, including railings, patio furniture and lampposts, just as long as you properly follow the simple directions.
Set up a work space in a well-ventilated area. Put on a pair of disposable plastic or rubber gloves, safety goggles or glasses, and a face mask. Place a plastic drop cloth beneath your work area to prevent dripping the jelly onto your floor, driveway or lawn.
Scrape the rusted metal with a stiff wire brush to remove any dirt and large patches of loose rust. Use a steel wool pad to scrape small rusty areas and clean out any crevices. Wipe the scraped area with a clean, dry cloth.
Apply a thick coating of naval jelly to the rusty metal using a disposable paint brush or roller. An old toothbrush works the product into crevices and pitted areas.
Allow the naval jelly to sit for five to 10 minutes so the chemicals have enough time to penetrate the rust. Don't leave the jelly on for more than 15 minutes or the chemicals could cause unattractive streaking or even etch the metal surface.
Saturate a clean cloth with water and thoroughly remove the naval jelly from the treated area. Dry the metal with a clean cloth.
Examine the metal for rust spots. Repeat the cleaning process until all the rust is gone.