Continued drilling through the opposite side until you complete the door knob hole in the door.
How to drill a hole in a glass door.
But use this approach on harder materials like metal masonry glass or tile and you ll waste time ruin drill bits and even wreck your workpiece.
The procedure can be long depending on the thickness of the glass and the drill bit needs constant lubrication in order to make it through the glass.
Then insert a diamond drill bit into a drill and position it over the spot you want the hole to be in.
Glass can easily be drilled with the correct drill bit and a suitable lubricant coolant.
Add more lubricating oil as needed to keep the drill point cool stop and replace the drill bit with the next size larger carbide tipped bit then continue drilling lightening up the pressure on the drill with each bit change.
Making holes in soft materials like wood is easy.
To drill holes through glass start by attaching a small piece of tape or cardboard to the glass where you want to drill the hole which will prevent the drill bit from slipping.
Put on safety glasses and drill pilot holes on the marks that are half the size of the final holes using an electric drill.
You just stick a standard drill bit in your drill and pull the trigger.
Insert the barrel into the hole from the interior side and hand thread the viewer together.
To avoid drilling through both sides of the door wrap the drill bits in masking tape allowing only 1 2 inch of the tip to show.
If the barrel fits the hole too tightly to rotate remove it from the hole.
Drilling into tempered glass requires special diamond drill bits in order to cut through the dense glass.
Apply firm pressure as you drill the hole into the door making sure the hole saw is flat and not angled as it goes through the door.
Put the drill bit back into the hole and run it for a few seconds to clean it up and enlarge it very slightly.
Once the center bit protrudes through the door stop and switch sides.
Then insert the lens into the hole from the exterior side of the door.