Scrub off any rust on the galvanized steel fencing with a wire brush.
Wipe off any rust flakes or other debris from the fencing with clean rags. Place a drop cloth under the section of fence to be painted.
Paint both sides of the fencing with either a paint brush or narrow roller. Allow the paint to dry per paint container instructions. Apply a second coat of paint.
Cllean the paint brush or roller in paint thinner or mineral spirits. If another paint session is needed, tightly wrap the brush or roller in two layers of plastic wrap, and place it in the refrigerator. When ready to paint again, simply unwrap the brush or roller; it may be a little stiff for the first few strokes, but will quickly become pliable.