Hello, my old car has flat flight grate and a few small bumps on the chassis and axle carriers, especially where the car once sat up. The body is however top. Now there are some places, because of the geometry you can not completely rust, but only with a beige the coarsest rust away. Now I know that rust converters after several hours/days influence time (it forms a black layer), must be overpainted necessarily. Is there any experience with rustproof paint from the hardware store, which can be applied with a small paint brush? I thought of metal base, hammerite, rust blocker, rustproof paint for rusty garden fences or garage doors, which can be painted directly on rust, does that hold well? MfG Chris