OSPHO Rust Treatment 1/4gal

When applied to rusted surfaces, it resists / retards rust in chemical change on drying to a tough, hard surface ready for priming. Paint jobs will last longer after an application of OSPHO because subsequent paint coating securely attaches itself so that moisture and oxygen normally do not attack the metal. Water-thin, covers a larger area than paint and goes on easily. Equally effective for exterior or interior.