Wash the scratched area with a mild soap and warm water. Avoid using harsh, abrasive liquid, powder or foam cleansers. Rinse clean and dry with a soft cloth.
Pat the carnauba wax onto any scratched area of the black refrigerator with a clean, dry sponge. Uncolored carnauba car waxes, like Turtle Wax, work best for a scratched appliance. Leave the wax in place for several minutes to allow it to soak in.
Polish the scratched areas with the polishing cloth. Purchase polishing cloths at auto parts stores or in the wood furniture care section of most department stores. Work in small circles, buffing the wax into the scratches completely. Carnauba wax softens rough edges and polishes out small scratches on your black refrigerator's surface.
Allow the wax to dry for 24 hours. Inspect the scratched areas, taking notice of any remaining, deep-set scratches. Use a dry, soft cloth to gently wipe off the wax on these deeper scratches.
Put on safety gloves. Use a low-grit sandpaper to very gently sand the scratched area until smooth. Do not apply too much pressure or remove too much of the black paint. The goal is to remove the scratch only in preparation for paint. Wet a soft cloth and wipe the area clean. Let the area dry before applying touch-up paint.
Follow the instructions on the black appliance touch-up paint (see Resources) to apply paint to the sanded areas. Touch-up paint is available in both pen, liquid and spray forms. The pen version is very effective for scratches because it allows you to work in small, precise areas with a controlled amount of paint to the scratched areas. Allow the paint to dry completely.