You can drill a clean hole through s ceramic porcelain sink without causing damage. Sinks made of composite materials like ceramic and porcelain are so strong and durable they require special diamond-tipped drill bits to cut through them. The process of drilling through a thick ceramic porcelain sink is slow. But using the right equipment and technique, you can customize a porcelain ceramic sink with the hole you want.
Apply a single layer of masking tape to the entry and exit sides of the ceramic porcelain sink where you intend to make the hole. Press out all the air bubbles so the tape makes complete contact.
Mark the hole size and location with a permanent marker.
Attach the appropriate-width diamond drill bit or diamond hole saw to the electric drill. Diamond hole saws are hollow in the center and cut the outline of holes that are 1/2 inch or larger.
Protect your eyes with goggles. Set the electric drill to a low speed setting, between 500 and 600 RPM.
Get the drill up to low speed before making contact with the marked hole location. Apply medium pressure as you hold the drill steady.
Hold a damp sponge on the side of the diamond bit or hole saw to keep it cool as it continues cutting through the sink at low speed. It may take as long as 10 minutes to drill all the way through a thick ceramic porcelain sink.
Peel away the masking tape from both sides of the sink. Allow the diamond bit to cool completely before you attempt to remove it.