Used on frames, floorboards, under fenders, engine compartments, trunk areas.POR-15 is a paint-like substance which acts as a total rust inhibitor and is also very effective as a metal filler. It’s consistency is approximately that of paint and it has very good spreadability (one quart covers 96 square feet). POR-15 chemically bonds to rusted steel to form a rock-hard, non-porous coating that won’t crack chip, or peel. It works by isolating metal from moisture. Without moisture present, steel can’t rust. Thin, covering coats are best; POR-15 will accept all paints, including lacquer-based paints. POR-15 works great as a concrete sealer and is impervious to fuels, battery acid, oils, etc., and when applied to concrete floors in shops or factories permits quick and easy clean up.