You can buy a porcelain patch kit to fix chips in your porcelain sink. You used to have to take two steps to repair it starting with a filler followed by a glaze to make it shiny. The video teaches how to use patch kits that you paint on like nail polish. To apply the patch you want to put on several thin coats and let each coat dry. When you apply the coats the key is to get the patch level with the rest of the sink. Then you can sand it with 220 grit sandpaper. After you have sanded the area use a white cloth to buff the area and give it a nice shine. Use the video to simply repair a chip in your porcelain sink.