A waterborne urethane acrylic bonding primer the strongly bonds to hard, glossy paints and other challenging substrates such as PVC, vinyl, fiberglass, glazed block, tile, pre-coated siding and galvanized metals. It levels to a smooth film to dramatically improve the topcoat appearance. May be topcoated with latex, alkyd, epoxy, urethane, or lacquer coatings. May be used in interior or exterior applications. It resists blistering, cracking and wrinkling of top coats due to moisture.