Don't know if this is the right forum, but since there are a lot of skilled craftsmen here, I thought I'd give it a try. I have successfully drilled holes in the bottom of glass bowls to use them as orchid pots. I've used a drill (Bosch GSR 14.4V) and a glass drill bit. I drilled a little at a time and flushed water over it occasionally. When I went to drill a hole in another bowl (which was a bit more "ornamented", uneven glass thickness, if that matters), a crack suddenly appeared in the glass, causing the bowl to loudly "explode" into many pieces. (I already feel like I'm going to get the advice "stop doing that, you idiot, it's dangerous", but I'm trying anyway...) I think (but feel free to contradict me if you want) that it can still be drilled successfully if I make sure to have more water present (perhaps keep the bowl completely underwater while drilling) and take it easy, and I can also take more precautions when drilling, if there is a risk of another "explosion", but... What I'm wondering is if it's possible to know that the risk of the bowl cracking is over once I've finished drilling and planted orchids in it, or can such tensions remain long afterward? I can make sure to protect myself during the work, but there mustn't be any risk that the children poke the bowl a week later and get flying glass shards in their eyes. 
There are different types of glass, some are tempered, others are not, and there are different levels of tempering. A glass jar with an "embedded" pattern is likely one of those that are harder to make a hole in. A smooth glass bowl is probably easier. It also depends on the tensions, so it's impossible to say what can and can't be done before trying.
Drill in water and put, for example, a plastic bucket upside down over the first hole you drill through so that if it explodes, everything is contained in the bucket. Thick work gloves and eye protection, of course!
As for whether it can crack later, sure, it's more sensitive than other glass, and I wouldn't "handle" it unnecessarily...
Drill in water and put, for example, a plastic bucket upside down over the first hole you drill through so that if it explodes, everything is contained in the bucket. Thick work gloves and eye protection, of course!
As for whether it can crack later, sure, it's more sensitive than other glass, and I wouldn't "handle" it unnecessarily...
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· Stockholms Län
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Like a dremel with some kind of stone/diamond grinding bit maybe?
Yes, I was planning to do roughly as anders07 describes it, but I am wondering if there is a risk of explosion even long afterwards. If the glass is more prone to cracking, that's not really dangerous, but if there's a risk of an explosion like the last time I tried drilling (and that explosion can also happen long afterwards), then it's not possible to use the pot. Does anyone know how sure you can be that it won't happen once you've finished drilling without problems?
Without really having any idea of how glass behaves when you drill into it, I guess that the temperature rise around the drill hole when drilling is the culprit.
I think: Hot glass takes up more space than cold glass, and the material closest to the hole wants to expand, while the colder glass around it holds back until it can't anymore, hence the "explosion."
In other words: if my theory is correct, the pot shouldn't be much more fragile once everything has cooled down...
I think: Hot glass takes up more space than cold glass, and the material closest to the hole wants to expand, while the colder glass around it holds back until it can't anymore, hence the "explosion."
In other words: if my theory is correct, the pot shouldn't be much more fragile once everything has cooled down...
Interesting thread!
I didn't know you could drill into glass, not something I'll dare to try myself but interesting to know that it's possible
I didn't know you could drill into glass, not something I'll dare to try myself but interesting to know that it's possible
The bowl that exploded is made of tempered glass, as mentioned earlier. It is a type of controlled cooling process that makes it tempered, and the idea behind it is exactly what happened to you: It should explode into many small pieces instead of cracking into shards. So just like a car window.
It might be possible to drill in tempered glass, but only under very special conditions. Instead, choose a "regular" glass, preferably crystal, as it is much "softer" than soda glass (the type of glass used in bottles, jars).
You did the right thing by cooling with water. Ideally, you should drill under running water so it stays cool all the time. The problem with glass is that it does not conduct heat/cool efficiently, which means the drill hole becomes much hotter than the surrounding glass. As someone mentioned earlier, expansion occurs in the warm surface, creating tension between the cold and warm areas – leading to a risk of cracking.
Yes, glass can crack from tension several years after manufacturing.
Check www.essemce.se, they have all the tools, grinding stones, drills, etc., that you need. It's easiest to call them, they are very friendly and send smaller orders in an envelope.
You can use grinding stones/drills with a regular dremel. Check, for example, at Claes Ohlson,
Good luck!
It might be possible to drill in tempered glass, but only under very special conditions. Instead, choose a "regular" glass, preferably crystal, as it is much "softer" than soda glass (the type of glass used in bottles, jars).
You did the right thing by cooling with water. Ideally, you should drill under running water so it stays cool all the time. The problem with glass is that it does not conduct heat/cool efficiently, which means the drill hole becomes much hotter than the surrounding glass. As someone mentioned earlier, expansion occurs in the warm surface, creating tension between the cold and warm areas – leading to a risk of cracking.
Yes, glass can crack from tension several years after manufacturing.
Check www.essemce.se, they have all the tools, grinding stones, drills, etc., that you need. It's easiest to call them, they are very friendly and send smaller orders in an envelope.
You can use grinding stones/drills with a regular dremel. Check, for example, at Claes Ohlson,
Good luck!
And Bödde, you mean that my planters (if they are made of tempered glass) risk exploding long after I have drilled into them, when they are on the windowsill with orchids in them (alternatively cracking if they are not made of tempered glass)? In that case, I probably wouldn't dare do it even if I were to get relatively good tools.
It's really difficult to know, for example, a Duralex glass is tempered, and it looks like any regular drinking glass... They should know where you buy your glass. If you buy it new, it should also be indicated on the packaging. If you're shopping at, for example, a flea market, choose glass that you can see is mouth-blown, as it is guaranteed not to be tempered. Many of the bowls sold at IKEA are also okay; there is both mouth-blown and pressed glass for a low price.gavagai said:
No, I simply don't think it's possible to drill into tempered glass without it exploding, so you need to find "ordinary" glass.gavagai said:
It was actually more of a response to the thread's discussion about whether glass can crack due to tension, which it can. But it can crack regardless of whether you drill or not, it's just how glass works. This applies to 99% of hand-blown glass and is due to incorrect cooling or mixing different colors that are not compatible.
However, this is not common, and if you work with the glass carefully using water (the drill core becomes several hundred degrees hot quite quickly), there's little chance of error. My first post might have sounded drastic, but that wasn't my intention! You can continue your craft without worry, just choose the right glass
I drilled a hole in a ceiling fixture, should I avoid going under it now? How do they do it in the manufacturing of fixtures with holes in them? Don't they drill last? I used a diamond drill bit intended for the purpose and a water bath, rigged in a pillar drill with foam plastic as a base so that I wouldn't force the drill bit sideways. I know glass can explode; I was washing a 50L demijohn, and the only piece left over a decimeter in size was the neck I was holding onto, and it had received the same treatment many times before. I read in a book that you could cut window glass with regular scissors if you held it underwater, although I've never tried it, sounds unlikely, but they claimed it was the vibrations/click that caused the glass to crack.
This is what I used, 10mm, http://www.vdb-glassart.se/webbshop/verktyg-för-bly-och-tiffany/glas-borr-7205761
That's right, I also taped the spot where I was going to drill. Mainly to keep it together if it broke, but maybe it affected the result, I don't know.
This is what I used, 10mm, http://www.vdb-glassart.se/webbshop/verktyg-för-bly-och-tiffany/glas-borr-7205761
That's right, I also taped the spot where I was going to drill. Mainly to keep it together if it broke, but maybe it affected the result, I don't know.
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No, it's not dangerous. I might have been a bit drastic in describing glass and how it can crack, but it was mostly to describe the material and that it can crack due to stress. Drilling in glass is not unusual at all, and it's safe as long as you're careful and cool with water. It can still crack during drilling, after all, it's glass, but if you've cooled and succeeded with the drilling, then of course you should use what you've made. I think your method seems spot on, and the drill bit definitely seems made for glass drilling! Smart with the tape, it usually prevents the drill from slipping and probably also prevents the drill hole from chipping - while keeping the shards together if an accident occurs. Cutting window glass? I've never heard of that, and I agree with you that it sounds unlikely...ion said: