Not only is rust on your car's frame an eyesore, but it also can cause excessive damage. Rust will weaken the frame; if it's not contained, it will continue to spread. It is critical to remove rust the moment it becomes apparent.
Using a sanding wheel to buff out the rust is ideal; however, it is not required. If you remove some of the paint around the area it is all right because you are going to paint the area later. Simply remove the rust with sandpaper until the frame is free of any rust specs and spots.
Before you paint the car, wash the area free of dirt and any rust debris that may have stuck to the side of the car. Dry the car off. Paint the area with the primer. The primer helps cover up the rust area and allows the paint to adhere better to the car. Allow the primer a few hours to dry, then apply a layer of paint. The paint is going to help prevent rust from appearing in the future. Allow ample time to dry before taking your car out to drive.
Once you have finished painting the car, apply a rust-proofing spray onto the area. Once an area has rusted it becomes more susceptible to rusting in the future. Using the preventative rust spray is going to help tremendously. Apply the rust proofing spray onto the car and give it another couple of hours to dry. You should not need to apply more rust proofing to the area for a few years now.
