When is it appropriate to apply a base coat on a vehicle?

Applying a base coat on a vehicle is appropriate after all body repairs are complete. This ensures that the surface is perfectly prepped and ready for painting, allowing for optimal adhesion of the paint. Once the repairs are done, any necessary surface preparation, like sanding and cleaning, should be finished, setting the stage for the base coat application. This process helps to conceal any imperfections that might have occurred during the repair work and enhances the overall finish of the vehicle.

Other options do not align with the correct process. Applying a base coat before sanding would result in a poor finish, as rough surfaces can affect the adhesion and appearance of the paint. Washing the vehicle is crucial, but it should typically be done before repairs and surface preparation, not immediately before applying the base coat. Lastly, the notion that a base coat is only used on new cars is incorrect; base coats are part of the refinishing process for any vehicle that has been repaired or repainted.