Whats the best way to take a panel thats half original paint, half surface rust (desert car), and prep it for paint/ primer? When the surface rust is sanded off it still looks like theres very minor pits with rust still in them. What do I coat that with to be sure its gone and does't come back as a bubble later? Can you primer on top of an over the counter aerosol rust converter spray? I'm wanting to do my own body work and want make sure I take the right steps. Also do I sand off the factory primer on the non surface rusted part of the panel?