How to Knock out Holes in a Blanco Sink

Blanco uses knockout holes for its line of Silgranit sinks.
Prefabricated "knockouts" make installing a Silgranit sink less difficult when you need holes for the faucet that are not currently on the sink. A Silgranit sink usually comes with three holes for the faucet. The knock-out holes on a Blanco sink are perforated on the bottom; but knocking one out's not just a game of Whac-A-Mole. Knocking out the hole requires a special hammer so that you don't damage the surrounding sink surface.

Step 1

Place all of the packing foam that was around the new Blanco sink back into the box. If you do not have the original box, place a thick blanket on the floor. The bottom of the sink must be cushioned to avoid damage.

Step 2

Position the sink right-side-up on the box or blanket. Find the two white dot stickers. These stickers indicate the centers of the knockout holes. Look under the sink to ensure the dots are on center of the knockout holes.

Step 3

Hold the back of the sink near the knockout hole with one hand. Tap the white dot sticker with the round end of a 6-oz. ball-peen hammer. Do not hit hard; simply tap it a few times until the hole pops out of the sink flange and into your hand.

Step 4

File the inside of the hole lightly with a fine file to remove any burrs.

Things You Will Need

  • Blanket
  • 6-oz. ball-peen hammer
  • Fine file

About the Author

Kenneth Crawford is a freelance writer with more than 10 years of experience. His work has appeared in both print and online publications, including "The American Chronicle." Crawford holds an associate degree in business administration from Commonwealth College.