How do you drill a 2 inch hole in a piece of glass?
I need to put a hole in a glass table in order to hold a patio umbrella. Any ideas how I could go about this? I have read about using a drill in order to make a hole, but I am looking how to safely expand a drill hole to two inches in this table top.
8 Responses
Terry O
04 Feb 2010
dindo
04 Feb 2010
I don’t suggest doing it alone, especially if this is your first time. Just hire someone who is expert on this, less money spend on the long run than breaking the whole table glass if ever.
Ozgood
04 Feb 2010
This would require a diamond coated hole saw, and even if you had one you wouldn’t be able to do it "free hand", it would have to be in a drill press or mill capable of reaching the center of the glass. You should be able to get this done at your local glass shop. btw, is that glass you’re using tempered, or safety glass.
DaDiva
04 Feb 2010
It’s best not to drill into glass. You should get a glass cutter for the job. They have them at the hardware store, or you can take the glass to the hardware store and they may cut it for you (some do).
Malcolm D
04 Feb 2010
I hope its toughened glass your using as if not it sounds very dangerous to me.Certainly not a job for an amateur.
Elliott M
04 Feb 2010
with a fine grit conical grinding bit
Jazz_Chi
04 Feb 2010
Unfortunately for you, it either can’t be done or you should ditch the table for safety.
The vast majority of patio tables for sale are tempered, which makes them quite strong. Tempered glass also has stored energy which causes it to shatter into relatively dull squares when broken, lessening the chance for serious injury. Unfortunately, these properties will also cause the table to shatter if you try to cut a hole for your umbrella.
Non-tempered glass will shatter into long shards which have even killed people (see source). A diamond hole saw will be able to cut holes in this type of glass if done carefully (slowly, lots of coolant, etc.), but do you really want that kind of safety hazard around? Incidentally, cutting the hole will create flaws and make the table even more likely to break.
My advice: bite the bullet and buy a new tempered glass top with the correct sized hole or get a cantilevered umbrella like this one (http://www.teakalook.com/prodDetail.cfm/13352) to cover the table.
mike1942f
04 Feb 2010
The majority of table tops are NOT tempered, because the scratches and chips that do occur in ordinary use would cause it to destroy itself. But having taught myself to drill glass after a bunch of reading about it, I would NOT recommend doing a hole this size on your own. Just the diamond edged bit is fairly expensive and the drill and water cooling and bracing you need to work in the middle of the table top add to the cost. http://users.ticnet.com/mikefirth/coldwork.htm#DRILLING
Look up mirror and table top glass shops in your area and ask the cost of having a hole drilled. They do a lot of drilling of glass for outlets, pivot holes and umbrella poles. It will be less than a new drilled table top and they will be able to check on any tempering before they start drilling.
Tools, Drill, Carbide or diamond drill bit with guide bit, 1x6x6 piece of wood for backing, modeling clay or a toilet bowl wax ring 1/2 inch dowel and 1.5" dowel, 1 sheet each 240, 600 and 1000 or 1200 grit wet n dry.
First set the top so you can clamp the wood piece to the bottom of the table top. Use the clay or wax ring to build a water dam around the hole. The dam needs to be bigger than the bit. Mark the center of your hole on the piece of wood and just start the guide bit in the wood, say maybe 1/4".
Add water to your pool and set the bit in the drill in the guide whole. Do not put pressure on the bit, it will cause the glass to break. Just let the weight of the drill do the work and keep it level.
After you have drilled the hole, remove all the boards and water. Use Wet n Dry to smooth the hole. I would start with a 240 and once smooth, go to 600 for finish. If you want a semi polish to it, you can go to 1000 or 1200 to finish. I would use round dowels to do the work inside the hole and around the edges. Keep the area wet to prevent glass dust.