How to Secure a Kitchen Sink to a Countertop
Check the surface of the countertop before attempting installation of a new sink. The countertop should be free of damage and should not be weakened in any way. The counter surface should be as smooth as possible and free of old adhesives in order to form a strong seal. Use a utility knife and alcohol to carefully remove old adhesive.
Clean the inside lip of the sink. This surface needs to be free of dirt and dust to allow for proper adhesion to the countertop surface.
Place the sink inside the counter opening to test for proper fit. The sink should overhang the counter by a half-inch or so to allow for complete adhesion of the sealant to the counter surface.
Perform a test run to check the fitting of your faucet and drains. Make sure both fit into the designated drain and faucet holes properly. Trying to cut holes for faucets and drains after the sink is secured is next to impossible.
Install the mounting clips to the underside of the sink based on manufacturer's instructions.
Apply a uniform bead of sealant around the entire edge on the underside of the sink lip. This line of adhesive should be continuous to prevent water seepage under the sink once it's secured to the countertop. This adhesive dries quickly, so be prepared to place the sink immediately.
Place your fingers inside the drain holes of the sink and flip it over for placement in the opening in the countertop. Align the sink and firmly press down to form a seal between the sink and countertop.
Tighten the mounting clips under the countertop until the sink presses completely against the counter.
Wipe any adhesive off the countertop with alcohol.