Remove any fixtures from the sink that can be removed.
Apply the resin per the kit's instructions to any scratches, chips and dents. Some deep scratches or dents may need to be covered with fiberglass mesh, which comes with the kit, before applying the resin. Let the resin dry and cure completely.
Sand the repaired area with a fine grit sandpaper. Thoroughly clean the area and mask any fixtures that could not be removed with newspaper and masking tape.
Apply the chemical cleaner or the acid reducer that came with the kit. This is important because it will allow the new coating to properly adhere to the surface of the sink.
Apply the first coat of the porcelain paint with a spray gun using even, steady strokes. Allow the first coat to dry and apply a second coat. After the second coat dries, apply a third and final coat.
Buff the surface of the sink with a buffing wheel attached to an electric drill. Finally, replace any fixtures and hardware that were removed.