Drilling Glass

[runwoolf]

Making some wind chimes and I need to drill a quarter inch hole in a half inch thick convex piece of glass four inches in diameter.
Only get one chance. Any pointers?? Thanks and Happy New Year to All !!!

 

[Eman85]

Been a long time but I used a glass bit and made a dam with glazing compound and I think I used mineral spirits in the dam to cool the bit.

 

[Geo-TH,In]

Making some wind chimes and I need to drill a quarter inch hole in a half inch thick convex piece of glass four inches in diameter.
Only get one chance. Any pointers?? Thanks and Happy New Year to All !!!

Amazon sells diamond drill bits that look like hole saws. I use drill press and water

 

[Watthour]

I got lucky a few times with carbide spade bits made for glass. They required slow speed and light/moderate pressure. I actually got one successfully through a piece of tempered glass once. When attempting the second hole, however, the piece of glass rapidly "distempered" itself into what was probably a couple thousand pieces.

I have since graduated to diamond edge boring bits and use plain water as a coolant/lubricant for boring. I've also not had any inclination to try a piece of tempered glass again, but have had success with plate/float glass numerous times, and with some relatively larger holes.

 

[1948CaseVAI]

Making some wind chimes and I need to drill a quarter inch hole in a half inch thick convex piece of glass four inches in diameter.
Only get one chance. Any pointers?? Thanks and Happy New Year to All !!!

I bought a set of glass bits on Amazon and they work perfectly even on rounded surfaces such as the side of decorative bottles I make lamps out of. They do require a few drops of water while drilling.

 

[Buffalo Pete]

Keep dribbling water on the carbide spade bit. Best to use a drill press to control your feed. Be REALLY careful as you start to break thru to the other side to carefully slowly feed the drill bit to go thru and enlarge the hole to the drill size.

 

[Charles in Aus.]

Go slow with the best carbide dril you have or invest in a diamond core bit of the correct size , don't drill a pilot hole , don't push hard or use a hammer action .
Place the whole piece under hot water and drill while it is fully immersed, rest the piece on an entire double folded newspaper for vibration absorbence.

 

[DanielW]

I've drilled a lot of glass tile (and the odd old-style slider window). As others have said - keep the bit cool. Constant spraying with water or some other cooling fluid (or keeping it immersed using the dam method above) is critical. As soon as you create any heat, the glass will shatter. Diamond bits for glass are readily available at any hardware store or online for less than $10 a piece. Best to get the correct bit for the job.

 

[WNYBill]

We had a 4x8 window that lost its seal and got condensation between the panes. We tried to drill a small hole in a corner, it was neat to watch the 4x8 go into a million pieces! 40+ years ago, before carbide and diamond drill bits and we never heard of cooling.

 

[cleddy]

I have a 1960 car windshield some kids smashed a big jagged hole in it. They are hard to find and don't want to really spend any money on it. Can I square the opening up with a diamond saw disk and epoxy a nice patch in it? I think it old laminated glass with a plastic layer in the middle.

 

[DanielW]

I have a 1960 car windshield some kids smashed a big jagged hole in it. They are hard to find and don't want to really spend any money on it. Can I square the opening up with a diamond saw disk and epoxy a nice patch in it? I think it old laminated glass with a plastic layer in the middle.

I cut a large hole on an old glass windshield of a 70's VW bug with a diamond hole saw meant for glass. I think you could theoretically do what you're suggesting, but a couple of my worries might be:

a) Heat is even more of a concern with a saw/diamond disc than with a drill bit. I've used a diamond glass masonry blade to cut a lot of glass tile. Similar to drilling: as soon as it starts to heat, it will shatter into oblivion. You have to go uber slow/careful with a constant supply of water/coolant. There's still a good chance something might go awry and you'd lose the whole windshield. An angle grinder with a glass diamond blade works, but it's a little finicky because angle grinder RPM is so high - it's very easy to heat things accidentally.

b) You probably wouldn't want to cut it with square corners, as these will be stress concentration points and cracks will develop out from the corners in very short order. I think you'd want to radius the corners, which would be some tricky cutting. Drilling the four corners with a diamond hole saw and cutting between would probably be the best bet. But then you're not only cutting four times, but drilling four times as well - lots more potential for things to go awry.

Have you gone to a windshield place that works in Lexan? Some windshield places can make new windshields to match old/rare ones out of Lexan (which is like a tougher, scratch-resistant plexiglass). Might be another option for you.

 

[cjunrau]

Making some wind chimes and I need to drill a quarter inch hole in a half inch thick convex piece of glass four inches in diameter.
Only get one chance. Any pointers?? Thanks and Happy New Year to All !!!

diamond bit and find a container to put it in and drill it under water. That is how I have done all my glass drilling. I use a drill press.

 

[Absent Minded Farmer]

My emphasis would be on the water. Not only is it a coolant & lubricant.... it keeps you from inhaling the dust & getting it all over. And take your time, don't push in it too hard.

I've done all sorts of glass work & keeping the dust down is a must. Well.... glass blowing is different, as you don't want to use water & pray you don't have a blowout, sending tiny shards into the air.

Mike

 

[Charles in Aus.]

Mentioning water as coolant can be misleading . It conjures ideas of cold, which is not desirable when cutting or drilling glass . Yes , it's important to keep the bit temperature low , but even boiling water is low compared to the heat developed from friction at the drill face . By immersing in hot water the bit temperature is stabilised and the localised hot spot in the glass caused by drilling is moderated . Temperature differences within the glass are a major contribution to cracking .

 

[runwoolf]

Making some wind chimes and I need to drill a quarter inch hole in a half inch thick convex piece of glass four inches in diameter.
Only get one chance. Any pointers?? Thanks and Happy New Year to All !!!

Done. Diamond bit, water, very slow. Thanks!