RUST-OLEUM STOPS RUST primer sprays provide a sound base for application of STOPS RUST enamels on heavily rusted metal. Use of primers promotes topcoat adhesion and helps prevent chipping, cracking and peeling and eliminates the need for multiple coats of enamel finish. It features a comfort tip with a wider finger pad to reduce fatigue caused by continuous spraying and the any-angle tip which allows you to spray at any angle. Not for use on galvanized steel.