Galvanized metal is most typically found on outdoor items or those likely to stay in contact with moisture or water, such as storage sheds, chain-link fences, and metal on boats. Galvanized metal is coated with a layer of zinc to protect the iron or steel underneath. If the item is exposed to continually wet conditions, the zinc develops a film known as white rust. Left untreated, white rust corrodes the zinc, and the metal underneath begins to rust, exhibiting the more traditional brownish-red color. To protect the integrity of the item, repair galvanized metal rust as soon as it is noticed.
Apply vinegar to the rust. Pour some vinegar on a wire brush, then scrub the rusted area thoroughly.
Wash the area with a garden hose to neutralize the acids in the vinegar. Examine the area for stubborn rust stains.
Put on protective plastic or rubber gloves and safety goggles, then open the Naval Jelly. Add to water to make a solution that is about 95 percent water and 5 percent Naval Jelly. Mix thoroughly.
Paint the mixture onto the rusted areas. Allow to sit for 10 minutes, then immediately rinse the solution from the surface of the metal. Examine the surface for remaining rust. Repeat the Naval Jelly and water application until all rust is removed. Wash thoroughly and dry the panels once all rust is removed.
Apply a zinc-rich paint over the repaired area. Select a paint that matches the existing color of the metal as closely as possible. Allow to dry. Weathering will eventually match the color of the repaired area with the rest of the metal.