Can someone give me information on drilling glass.

[Delphinus]

I freehand drill all my holes, in fact did a 1.75" last night and a 5/8" hole this morning.

The trick that I was told by my glass drilling "mentor," that I think is pivotal, is to start the hole at an angle until you have a groove that can hold the drill in place, then slowly rotate to horizontal. All the meanwhile, not too much pressure, and only about 1/4 speed of the drill.

The only thing about enlarging an existing hole, is, if you're going to use lubcricant it will be a challenge to keep the lubrication in place. If it were me, I'd probably try something like duct tape on the back side so the liquid doesn't pour through and disappear on you too quickly. It's just a thought, I haven't tried this myself so please do take my advice with a grain of salt!