Ceramic toilets have thick walls and heavy glaze. The glaze acts as a barrier to prevent damage to the underlying ceramic. Ceramic is a fragile material and can easily chip, crack or break when attempting to drill through the surface. Passing through the glaze is the most difficult part of drilling through ceramic. Drilling through a toilet requires specialized tools and a steady hand to avoid irreparably damaging it.
Mark the placement of the hole directly on the toilet.
Place two to three layers of masking tape over the mark and redraw the mark on top of the tape. Masking tape helps to keep the ceramic from chipping and breaking. It also gives the drill bit a place to grip without slipping.
Install a carbide or diamond ceramic-cutting drill bit into a power drill. Choose a drill bit that specifically indicates it is capable of cutting through porcelain or ceramic.
Position the drill bit on top of the mark. Turn the drill on. Apply light pressure to the drill to begin boring the hole.
Stop drilling as soon as you pass through the glaze. Brush the dust away with a paintbrush or damp rag.
Use plain water to wet the beginning of the hole and the drill bit to keep the drill bit cool. Position the drill back into the hole and drill again. Stop drilling every 1/8 inch to clean out dust and to wet the hole and bit until you pass through the ceramic.