Drilling glass?

[myboostedgst]

A couple of buddies and I are looking to build a glass top table. What is the best way to drill glass? We have a a single piece of square glass and we need to drill 8 holes for the head studs.

 

[geotek]

I'm the first here so i get to say it: CAREFULLY!!!

 

[phy6]

If it's not tempered, you can use diamond dust coated drill bits. Their head is shaped like a spade. Put a ring of putty around the drill site and put some water in there, to keep the cutting surfaces cool.

 

[porschedude996TT]

Diamond shell cutters is the only way to go with a sponge wet with water.

 

[mbatarga]

Hitachi makes some diamond tipped drill bits that are available at Lowes. I walked down the aisle and saw them just earlier today.

 

[chris fresh]

slow is better on your speed,the spade ones work well and start out as small as you can and work you way up.cheap modeling clay around the spot to be drilled,filled with water like mentioned above,helps also.or run a ring of silicone around the spots the night before.

 

[DHS]

Bad Dog drill bit do drill glass pretty good. They will drill just about anything.

 

[893cv]

A sandblaster will pop a hole in sheet glass. I've used good duct tape to mask off the area around the hole.

 

[Sureshot]

I have used a tapered burr carbide bit in a die grinder.

 

[myboostedgst]

Thanks for all the info guys. I will let him know and let him decide what to do.

 

[phy6]

I used the $10 (?) pack of 5 diamond bits from harbor freight. One of the smaller ones snapped when I was drilling through a rock (probably due to heat), but the other ones worked fine.

 

[badgcoupe]

I've drilled a few aquariums with special hole saws and I was always told to let the weight of the drill do the work but that (in some cases) was still to much pressure. I've often found the need to take a little weight off the drill when going. Putty ring with water is essential.

.02

 

[shoot summ]

Lot's of good advice, I will throw another angle on it.

Most larger areas have a least one shop that does the work for the glass shops cutting glass for shower doors, hinge insets, etc. I would call a glass shop and see what they would charge to drill the holes. You might be surprised at the cost(one way or the other). At least that will let you know if the effort is worth it.

 

[rlitman]

Funny this came up. I've been seeing a glass drill press on CL locally for about a month now. The idea is, it supports the drill with a tripod to keep it aligned.

Going slow is important, and the advice above is good. You can use the carbide spade for small holes (under 1/4"), and diamond for larger. The important thing is to not go off alignment and get the bit stuck. That can ruin your work in an instant.

 

[myboostedgst]

Should we start small and work our way up? The hole will have to be close to a half inch, so should we do multiple holes through or just a small single pilot hole through and then move up to the size?

The info about the putty is great. We were trying to figure out how to keep water over the hole.

 

[78Bird]

set up outside and let the hose run a trickle.

 

[MoonRise]

Glass table-top, eh?

If the glass is tempered glass, forget about it. You can not drill (or cut, or grind, or machine) tempered glass. If you try to do so, you end up with a pile of broken glass shards/chips/crumbs as the glass just shatters.

If your glass is not tempered and you are making a table-top, I'd suggest rethinking and using tempered glass for the table-top. The glass is 'stronger' and safer (generally breaks into little pieces if it does break instead of larger glass shards or daggers like 'regular' glass does when it breaks).

As to drilling holes in regular glass, the diamond-coated 'tube' bits are the way to go. The spade bits may or may not work (without chiping or shattering the glass), the diamond bits will work (RTFM and use water!)

The 'make a dam around the hole location with some putting' is a good trick. Either that or you can just run a (small) trickle of water constantly onto the bit as it is cutting (grinding).

In general, you don't do a pilot hole and then larger holes. Just get the diamond 'core' bit of the desired diameter and make one hole.

Other option is to get a tube of the desired diameter, chuck it up in a drill-press (so you are not having to hand-hold a drill and not wiggle or tilt or move while you are drilling the hole), and use some abrasive goop/compound (like a carbide or diamond paste such as a valve-lapping compound from an auto store), and let the abrasive paste 'grind' the hole. Done.

But if you can just get a diamond-coated glass bit of the desired diameter, I'd probably just get that.

But see above about not drilling tempered glass and about using tempered glass (Highly recommended) for a glass table-top.

 

[e30bradley]

diamond.. maybe carbide? I've tried with regular drill bits.. it doesn't work.

 

[gorilla]

I think that your best bet would be to have the holes cut with a water jet cutter, they cut glass like butter.

 

[rlitman]

Should we start small and work our way up? The hole will have to be close to a half inch, so should we do multiple holes through or just a small single pilot hole through and then move up to the size?

The info about the putty is great. We were trying to figure out how to keep water over the hole.

Forget trying to drill a 1/2" hole in glass as a solid hole in one shot. 1/4" ok, sure. 1/2" no way. You certainly do not want to step up in sizes. That causes chatter, which is a big no-no with glass.

. . . As to drilling holes in regular glass, the diamond-coated 'tube' bits are the way to go. The spade bits may or may not work (without chiping or shattering the glass), the diamond bits will work (RTFM and use water!)

The 'make a dam around the hole location with some putting' is a good trick. Either that or you can just run a (small) trickle of water constantly onto the bit as it is cutting (grinding).

Yup. They make a core cutting bit. It just cuts around the outside, and removes a slug of glass. This is your best bet for a hole that size.

Personally, I would set up a constant trickle of water to keep washing over the cut. The dam is a good idea to keep it cool, but the mixture of water and cut glass will make a slurry that will really slow down the cutting (raising the risk). A fresh and running supply of water, will keep the diamonds in contact and constantly working.

I for one, prefer a thick glass table (3/4") to a tempered surface. But I really wouldn't want to think about drilling that.

On that note, does it really have to be drilled? Glass tables usually are made to have gravity keep them in place.

 

[KULIWOBBY]

I think that your best bet would be to have the holes cut with a water jet cutter, they cut glass like butter.

X2 on this. We do it a lot where I work. But if you can't get to a shop with one then the other options will work.

 

[leon renaud]

My dad used to use valve lapping compound and pieces of tubing to make holes in glass. He would put a putty dam around where he wanted the hole and put several drops of kerosene in the putty dam he also mixed his valve lapping dust with kerosene not water. He would use the tubing as a drill he would let the tube turn a few times and then lift it slightly to let the valve compound get back under the end of the tube. He would just keep pumping the tube "drill" slighly up and down as he went to renew the compound under the tip until he ground a hole the size he wanted in the glass. The kerosene cooled and lubricated the area being "drilled " better than water. In the glass shops Ive worked in the glass cutters were all used with kerosene as lube even brand new cutters were set into cans of kerosene just deep enough to cover the cutter heads.

 

[AeroNautiCal]

Don't use a centre punch prior to drilling and don't use a hammer action drill...

 

[rlitman]

My dad used to use valve lapping compound and pieces of tubing to make holes in glass. He would put a putty dam around where he wanted the hole and put several drops of kerosene in the putty dam he also mixed his valve lapping dust with kerosene not water. He would use the tubing as a drill he would let the tube turn a few times and then lift it slightly to let the valve compound get back under the end of the tube. He would just keep pumping the tube "drill" slighly up and down as he went to renew the compound under the tip until he ground a hole the size he wanted in the glass. The kerosene cooled and lubricated the area being "drilled " better than water. In the glass shops Ive worked in the glass cutters were all used with kerosene as lube even brand new cutters were set into cans of kerosene just deep enough to cover the cutter heads.

Good point. Kerosene is also the best way to lubricate a glass cutter.
Water WILL cool better, but water will also evaporate.

Don't use a centre punch prior to drilling and don't use a hammer action drill...

LOL