Why steel rusts
Iron combines with oxygen in the presence of water to form rust. Humid summers, frequent rain and winter road salt all speed the process, and rust spreads under paint once it starts.
Where it starts first
Rust begins where water sits: the bottoms of posts, the tops of horizontal rails, weld seams, hinge areas and the insides of tube ends. Scratches and chips in paint are the second most common starting points.
Prepare before coating
A finish is only as good as the surface under it. Remove loose rust with a wire brush or grinder, clean off oil and dirt and apply primer promptly while the metal is bare.
Choose the right coating
Rust-inhibiting primer with a durable topcoat works well on most outdoor steel. Zinc-rich primer offers added protection at welds. Powder coat and galvanizing suit parts that can be sent to a shop.
Fix drainage and design
Drain holes in tubes, sloped tops and gaps that let water escape reduce rust risk. Sealed tube ends keep moisture out of hollow sections.
A simple yearly routine
Wash off dirt and salt, look for chips and bubbles and touch up early. A little paint each year costs far less than a rebuild after rust has taken hold.
Touch up chips early, keep water from sitting and never paint over loose rust.
