Granite sinks are used in designing kitchens and bathrooms, in large part due to their durability and longevity. As with all natural materials, however, a granite sink can be damaged or chipped if you don't take care of it or misuse it. Use the sink only as recommended; place items into it gently to avoid damaging the sink. When small chips occur, repair them with epoxy resin.
Clean the chipped portion of the granite sink completely with granite cleaner and a nylon scrub brush. Scrub the area firmly to remove all traces of dirt and algae, as well as any other debris that may cause the epoxy resin to fail. Allow the sink, especially the damaged area, to dry thoroughly before continuing.
Colour a small portion of the epoxy resin with epoxy resin colour, available from home supply stores, matching it to the colour of your sink. Stir the colour into the epoxy resin thoroughly with a putty knife, taking care to distribute the colour evenly throughout the epoxy. Combine the coloured epoxy resin with the remainder of the epoxy, mixing it with the putty knife.
Spread a small amount of the coloured epoxy over the chipped area of the granite sink with a razor blade held at a 45-degree angle. Continue adding epoxy, working quickly, until the chip is filled with the coloured epoxy and is level with the surface of the sink.
Scrape excess epoxy from the surface of the sink with a razor blade. Avoid using excess pressure as it may cause the razor blade to gouge the surface of the granite. Allow the epoxy to set for about 30 minutes, then sand it gently to remove any rough edges. Leave the sink undisturbed for four to six hours until the epoxy is thoroughly cured.