2 Pack. Henkel Loctite 1381192 8oz Duro Extend Rust Treatment. Duro Extend Rust Treatment Brushed on white and chemically reacts with rust to for a tough black polymer barrier that serves as a primer and that locks out future rust. Effective on mild surface rust. Can be sanded and painted over with oil based paints & lacquer. Use on wrought iron railings outdoor furniture mailboxes swing sets etc.