Drilling Holes In Glass

by Pat Rowe
(Cape Coral, Fl.)

I have been trying to drill holes using water, but I get almost through and the glass snaps. Can you give me any pointers? Thanks, Pat

Answer

There are several ways you can drill holes in glass. The easiest way, with the best results, is to use a Dremel electric multi speed drill, in a drill press. If you plan on drilling a lot of holes, the investment is worth while. You can buy a small drill press for a Dremel at Sears. It is less expensive than the Dremel brand drill press and works just as well.

You will also need diamond coated drill bits. I get mine at Harbor Freight. The last ones I got were $6.00 for 20 bits. Some were not appropriate for drilling glass, but there were enough to keep me drilling for a very long time. You can also get expensive ones made by Glastar. They are more than $6 each and (at least for me) don't last any long than one of the cheap ones.

Use a shallow contained, larger than the glass you will be drilling. Put a thin piece of styrofoam in the bottom. The foam protects the drill bit from hitting the bottom of the pan, and it protects the pan from having holes drilled through it. Set the drill press so the drill will go 1/2 to 3/4 of the way through the foam.

Lay your glass on the foam and put enough water in the pan to just cover the glass. Using a medium speed, pull down the handle on the drill press and slowly drill through the glass. The speed of the drill is important. Start at a slower speed and experiment with adjusting the speed until you have a speed that works for you. You would never use the highest speeds because they cause too much heat, from the fast drilling, and cause the glass to break.

Another way you can drill a hole is to make a dam on the glass, with clay. It will hold the water around the area you will be drilling. Pour water in the dam. I have also heard of people using oil in the dam instead of water. I have not used oil, so I can't comment on it.

Holding the drill at an angle, start the hole. Slowly straighten up the drill until it is perpendicular to the glass. The biggest problem with this method is that the drill skips when you first touch the glass, leaving marks on the glass. It is almost impossible to hold the drill steady when it's not in a drill press.

A third way, and the most unpredictable, is to use a small 1/16" bit on your grinder. You really need at least three hands to do it, and the outcome can still be a mess. Start from the bottom side of the glass. Wet the glass and hold it at an angle to the bit. Start the hole, then straighten the glass. You will need to take the glass off and re-wet it every several times as you are drilling. You don't want glass dust to fly around. It's a good idea to wear a dust mask while using the grinder technique. If you don't hold the glass absolutely level, once you get the hole started, your hole will be angled through the glass rather than straight up and down.

If you go the Dremel route, you will find so many other uses for the Dremel, both for glass work and non glass work. It is my favorite multi purpose tool.