Granite is a strong and durable stone with a natural beauty that makes it a common building material in the home, especially in countertops. Even with the strength of granite, there are occasions when your installed granite surfaces may chip. These chips can greatly mar the look of your granite surfaces, but can be repaired. Filling in the chips with a resin adhesive, coloured to match the granite, can restore the look of your granite surface. Using a hardener in the adhesive helps to build the strength of the patch, maintaining the overall strength for which the stone is known.
Clean the granite surface thoroughly using a mixture of trisodium phosphate (TSP) and water. Mix ½ cup of TSP into 2 gallons of warm water in a bucket. Dip a clean cloth into the mixture and wash the counter. Rinse the surface with clean water. Allow the surface of the stone to dry completely.
Apply masking tape to the side of the stone if chips from the stone are present on the stone edge or corner. Place the tape so that it runs along the side, with the top of the tape even with the top of the stone. Place the tape so that it forms a wall to the chipped area, so material placed in the chip does not run down the sides of the stone.
Mix enough epoxy resin in a paper cup to fill the chips in the stone. Use a wooden craft stick to mix the resin according the manufacturer's instructions, adding colourant to the mixture to match the granite.
Apply the resin to the chipped areas. Fill the areas with the resin until the patch is flush with the stone surface. For deep chips, layer the resin into the gouge, allowing the resin to dry before applying another layer. Allow the resin to dry and then mix and apply a filling layer, as the resin will shrink as it dries, necessitating a second smaller application to completely fill any voids in the chip. Scrape the surface of the stone using a razor blade to get the resin flush with the surrounding stone.
Place a piece of clear packing tape over the patch, and smooth the patch with your finger to give it a level, polished appearance. Allow the resin to dry completely.
Remove any excess resin from the surrounding surface by buffing the stone with 00 steel wool and the TSP mixture.
Remove the tape and polish the patch with sandpaper. Begin with 120-grit sandpaper and work your way up to 600-grit sandpaper, polishing the surface with each grit of paper until smooth.
Use multiple coloured patches for chip repair in granite containing two or more colours.