Epodur 7175 is used as a universal primer over marginally prepared steel substrates and as a bonding tie-coat over old existing, aged coatings. The outstanding wetting characteristics of Epodur 7175 allows the coating to penetrate tightly adherent rust and voids in existing coatings to yield a sound base for a wide variety of fresh topcoats. Being solvent free, edges of existing coatings are not lifted thus reducing undercutting and peeling of the existing coating.