Porcelain Tile / September 13, 2018 / Brousseau
Now that the pilot hole has been cut it is possible to drill the main (large) hole. Attach the appropriate diamond core and ensure that there is a constant supply of cold water (see water cooling information in the previous sections of this article). Diamond cores that are larger than 13mm will require an adapter with pilot pin that locates into the pilot hole that has been cut previously to ensure the perfect hole will be made. Starting the drill vertically begin to drill in a circular motion with sufficient pressure until the tone of the drill changes.
These methods will not keep the drill bits cool enough and will drastically shorten the life of the drill bit. Ensure that the drill is in normal mode and set the drill to between 1000 and 1500 rpm. If you have marked the tile with a marker it is best to drill into the tile using a method called leaning in. Leaning in ensures that the drill will not slip and wander off center as you begin to drill into the tile.
It is not advisable to try and cool the drill bit by using an aspirator or drilling through a wet sponge these methods will not keep the drill bit cool enough and the drill bit will burn out. Set the electric drill to between 700 and 900 rpm. Make sure that the drill is in normal mode. Push the carbide drill bit gently into where you have marked the tile until you hear a cracking sound. Start drilling from a vertical position with sufficient pressure and dont stop until you hear a change in the tone of the drill. As soon as you hear the change in the tone begin to ease off.