How to Install a Kitchen Sink
If you’re installing a stainless steel sink, you can probably handle the lifting and positioning yourself. However, if your new sink is cast iron or cast enamel, get a helper. These awkward sinks weigh 80 pounds or more.
Set the sink into the opening in the countertop.
Use the basket holes, not the faucet, to grip the sink. Center the sink in the opening and then draw a light pencil line on both sides and along the front edge of the sink.
Lift out the sink and flip it over.
You don’t need to take the sink back to your shop to do this, either. Lay a piece of cardboard on the countertop to protect it (and the sink) from scratching and then flip the sink over so that the faucet handles and neck hang over the edge of the countertop.
Apply a bead of silicone caulk (about 1/4-inch wide) around the edge.
The caulk prevents water from getting between the sink and the counter, and it also holds the sink in place. Use a silicone-based tub-and-tile caulk, which usually contains mildew killers and stands up against the dirt, soap scum, and crud that you’re sure to find around the kitchen sink. Silicone caulks also remain somewhat flexible, which is helpful because the sink will actually drop very slightly when it’s filled with water and then lift when the water is drained. The movement is very slight, but over time it would cause a regular latex-based caulk to crack.
After the caulk has been applied, you need to keep the installation moving so the caulk doesn’t dry before you get the sink in place.
Lower the sink into position using the pencil lines to get it in the same location.
Let the sink rest for about 30 to 45 minutes before you install the sink baskets so that the caulk has time to set up or cure.