Metal coating is a protective finish applied to metal surfaces to guard against rust and corrosion. Railings, fences, and structural metal all depend on the right coating to survive Denver weather, since bare or poorly sealed metal deteriorates quickly.
Metal prep is specific: rust is removed down to sound material, then a rust-inhibiting primer goes down before the topcoat is applied. Skipping the primer on bare steel is the fastest way to watch rust bloom back through the paint, leading to repeat refinishing work.