Our rust free primer contains citric acid and sodium gluconate. It can leave a thin composite film that sticks to the metal for months. Protect the metal surface from oxidation! Its use method is very simple: remove the floating dust oil stains and rust stains that are easy to fall off the surface of the painted object. After cleaning, paint the metal surface. After applying anti-rust paint, the original rust is transformed into a composite film with strong adhesion. Wait 10 minutes for the rust to turn into a black primer. And can restore luster, prevent rust again. Suitable for cars and homes.