Glass Drilling

I don't think anybody does this just for fun...

First off, know this.... I am NOT an expert at drilling glass.  I am a complete amateur...  However I did eventually have success and it was done using this setup.

After a little on-line reading and tips from a glass shop (they don't do drilling-so no reason not to tell me how to do it).  Best tips, drill all holes half way thru and flip to complete, use antifreeze as cutting lubricant (wear those nitrile gloves)....

I had to drill as many as 15 holes in each plate of glass and they needed to be accurately located, so I figured I'd have to do it on my drill press.  I was warned that the biggest problem in using a drill press is that you can easily apply too much downward pressure.  Before starting, I thoroughly cleaned and lubricated the quill of  the drill press and adjusted the return spring to its minimum spring tension to get the very best feel for how much pressure I was applying.  Also you need to make sure your drill press drive belt is properly tensioned and pulleys snug on their shafts to minimize vibration.

Any glass drilling requires coolant.  Most references say make a dam of clay around the location to hold coolant, but I would eventually have to drill 35 holes so I wanted something a little better...

What to make a coolant dam out of....  I got the bright idea to use a foam rubber toilet bowl gasket! 

I then thought of ways to clamp it down to the glass and had the idea to use a couple of suction cups and the plastic ring you see here...  It worked, sort-of, but the plastic was not rigid enough and I had to be really careful to 'burp' the suction cups to keep them holding for 15 minutes...  Eventually I decided I wanted a 'Plan B'.

So this is my 'Plan B'....

The DE-STA-CO swing arm clamp is easy to operate.

My little plywood ring was given a good soaking in quick dry polyurethane varnish.

I was happy with the way it works.

NEXT

I used a squeeze bulb to change the coolant every three to five minutes.  I discharged the coolant into a separate container so that the glass dust could settle out.

Drill speed depends on the diameter of the drill...  For 1/4" it was about 1000 RPM. For larger, proportionally slower to maintain approximately the same cutting velocity.

You pump the drill bit up and down to allow new coolant into the cutting surface.  I used about 300 strokes to cut 1/8" deep.

It's a slow process but there is no way I want to hear...

CRACK !!!