Things you will need
- Seal the silicone
- Two by four boards, longer than the sink opening
- Large C-clamp
- Mounting clips for sinks
Undermount kitchen sinks not only look more aesthetic in modern kitchens, they also make cleaning easier, as there is no edge in which food crumbs and leftovers can get caught. Since the sink does not hang by the edge over the fixed countertop, it must be completely attached and sealed at the bottom to prevent leaks.
Wipe the underside of the countertop where the sink will be attached with a duster.
Squeeze a thin line of silicone around the edge of the sink. Most undermount sinks have a 1-inch rim that is flush with the underside of the countertop. Apply the sealing ring to this rim. The sealing ring will expand when the sink is pressed against the stone, creating a watertight seal.
Place a two by four large board over the countertop and over the sink opening. Line up the sink under the sink opening and press it against the stone. Thread one end of the clamp down the sink drain and hook the other end over the plate. Tighten the clamp. This will hold the sink in place while the glue dries.
Mix the two part epoxy. Apply a small amount to the ends of the sink mounting clamps. Periodically around the perimeter of the sink, press the stems against the countertop next to the sink. Let the epoxy dry for 10 minutes.
Apply more epoxy to the clip area of the mounting clips. Press the clips onto the sink to allow the end of the clip to slide over the mounting post attached to the countertop. Let the epoxy dry for 10 minutes.
Slide the ends of the clips over the stems. Tighten the screws on the clips to hold the sink securely in place with a wrench. Allow the epoxy to cure completely for at least 24 hours. Remove the clamp and attach the drain.
Tip: Stone dust often collects on the underside of the countertop around the sink opening as the opening is being cut. This dust can adversely affect the connection of the sink to the countertop if not removed.