Drilling through glass

[shlomgad]

Can it be done with a regular drill ? Any special technique ?
Appreciate your advice on this.

[MAC702]

A drill press would be best, but it CAN be done with a hand-held, if that is what you meant by "regular." Chatter and vibration are your enemies.

There are special glass bits available, they usually look like tile bits (a spear-like tip) and are sometimes interchangeable. What diameter hole do you need? Is this a mirror?

You can use a piece of tape on the surface of the glass to minimize the walking effect of the bit on the slippery surface.

Medium to firm pressure with medium speeds. I'll see if I can dig up a speed chart to get more precise on the numbers.

Another technique is to use a piece of copper pipe of the same OUTSIDE diameter as the hole you want, remembering that this pipe is usually sized by inside diameter. You use the copper pipe INSTEAD of a drill bit by rotating it in a pool of abrasive, sort of a homemade mini core drill. You can keep the abrasive in the right place by building a dam out of wax or something.

The dam is also a good idea for the regular glass bit because it allows you to drill under water, which keeps things nice and cool.

So, hopefully even if you use a hand-held, you can get the piece in the flat position.

[Sandy]

With the DIY age upon us the glass bits are fairly common now-a-days. They've got them for tile, pottery, glass in limited sizes. Usually up to about 1/4 plus or there abouts. Problem with glass is there are many different types/tempers of glass. Firm backing with NO irregularities, just the right amount of pressure, don't let the heat build up and back off as you think you are about through and three out of four holes will go just right ...

The old cat skinners would tell you that you run a dozer with your a** connected to the machine (by feel). Glass is the same, you drill by feel.

Have fun

[scott brunsdon]

Old float glass can shatter pretty easily. As can thin - picture frame thickness - glass. Toughened laminated glass can be hard to get through. Get some scrap and do some test holes first. Your local glazier will have scraps in the bin.
Scott

[riley mcmillan]

I agree with mac702. I have used copper tubing and valve grinding compound on a windshield to take out a ding which I filled with silicone caulk. Also my wife does stained glass and she has a round cutter about one quarter inch dia. coated with diamond dust and it works really good turning about fifteen hundred rpms. Check out your stained glass shop.

[Brett]

Originally Posted by scott brunsdon

Old float glass can shatter pretty easily. As can thin - picture frame thickness - glass. Toughened laminated glass can be hard to get through. Get some scrap and do some test holes first. Your local glazier will have scraps in the bin.
Scott

Scott you cannot drill through toughened glass whether it be monolithic or laminated. .....don't even try!
Ordinary laminated annealed glass you can.

Can it be done with a regular drill ? Any special technique ?
Appreciate your advice on this.

It all rather depends on what size hole , what thickness glass and what type of glass.
Always endeavor to have holes as far away from edges as possible.
When drilling a constant mild pressure with the glass supported on underside is important.
Diamond and Tungsten tipped dills would be your first preference (never on hammer!)
A bit of water on surface wont go astray either.

Never heard of the copper idea before ....will have to try it

[shlomgad]

Thanks everybody for the useful tips.

[gary g]

Please make sure that you don't breathe glass dust. Drilling under water or solvent (kerosene, diesel fuel, WD40, etc.) will trap the dust & allow you to dispose of it more safely.

[awright]

I strongly endorse the use of a copper, brass, or other soft tube and abrasive slurry with very gentle pressure and lots of patience. I have used diamond dust and fine carborundum dust with good success on tile and glass. Cut or file slots across the tube radius to allow the slurry to get to the cutting edge and for the cuttings to wash out. Make sure everything is rigid and held in position firmly, but without stress on the cutting area. Use a clay dam to retain the water and slurry around the cutting area. This is the most gentle cutting technique, as if low pressure is used there is little tendancy to stress the glass. Gentle gravity feed is best if you can rig it up while maintaining the necessary alignment. Provide plenty of water and fine abrasive and go out to lunch, being sure you have anticipated what will happen when the drill breaks through.

I have never used a carbide arrow-tipped "glass drill" because the abrasive technique works well and I think the carbide-tipped drill is bound to create more stress on the glass.

Good luck.

awright

[Brett]

Originally Posted by awright

I strongly endorse the use of a copper, brass, or other soft tube and abrasive slurry with very gentle pressure and lots of patience. I have used diamond dust and fine carborundum dust with good success on tile and glass.

Good luck.

awright

The vast majority of the glass we use is toughened so we don't have the luxury of being able to drill holes in it, so we rarely drill holes in glass.
But occasionally we need to polish out scratches , in that situation we use Cerrium Oxide and its readily available .I say this as I have no idea how easy it is to get diamond dust or fine carborundum dust ....maybe they are easy to get???(Ive never tried) but if they are hard to source consider the Cerrium Oxide.

[awright]

Brett, I'll tell you where I get Carborundum and diamond dust if you tell me where you get Cerium Oxide.

Actually, I got most of my abrasives decades ago for this or that long forgotten project. One source was jewellery maker's supply stores. Otto Frei Jewelers Supplies in Oakland (www.ottofrei.com/800-772-3456) has a 500-page catalog full of fun stuff and tools, including abrasives for rock tumbling and rock and jewellery polishing. (In fact, I see that they stock Cerium Oxide.)

The other was a store called Optica b/c that catered to amateur telescope makers/mirror grinders. Another was a recycling center called Urban Ore here in Berkeley that happened to have several bottles of diamond dust come through. Once in a lifetime event, so don't call them up asking for prices on diamond dust. They won't know what you are talking about and didn't know what it was when they had it (fortunately for me.)

Long ago I got several grades of diamond dust in various grades in small hypodermic syringes to form and polish a tungsten carbide button into a spherical, lens-like surface in a lathe. I think that came from a tool supply company.

By the way, do you polish hydroflouric acid grafitti out of store windows? Can you describe the process and give a link to advice and supplies for the process? How about repairing/sealing/stopping short cracks in auto windshields? Are you a glass professional?

Have fun.

awright

[Brett]

>>>>Brett, I'll tell you where I get Carborundum and diamond dust if you tell me where you get Cerium Oxide.


It maybe a bit of a hike for your but .....

C R Lawence at Millperra Sydney NSW

[Brett]

>>>By the way, do you polish hydroflouric acid grafitti out of store windows?

No sorry mate, we do glass roofs and glass balustrades

[Brett]

>>>How about repairing/sealing/stopping short cracks in auto windshields?


No idea about windshields sorry

>>>Are you a glass professional?

Well in as much as I derive my income from glass structures..... yes

I'm a carpenter by trade , went on to being a builder , have a Dip in Str. Eng. love welding and have been to Tech for the last 3 years studying and learning it ( yes they ARE two very different things)

Currently we do glass roofs and balustrades ( design and construct)

[riley mcmillan]

Originally Posted by riley mcmillan

I agree with mac702. I have used copper tubing and valve grinding compound on a windshield to take out a ding which I filled with silicone caulk. Also my wife does stained glass and she has a round cutter about one quarter inch dia. coated with diamond dust and it works really good turning about fifteen hundred rpms. Check out your stained glass shop.

The cutter I am talking about has the diamond dust bonded onto it's surface. It came with a small machine that resembles a router table that my wife used to fine shape pieces of stained glass. It will cut through the glass like butter. I rigged up an adapter so I could use it in a hand drill motor.

[lucywalker]

notwithstanding the above comments, they havent made the glass yet that cant be drilled or cut using airborne or waterborne abrasives. can be used to drill, shape, polish. almost same goes for toolborne abrasives of certain types. effective abrasives for both airborne and toolborne use include silicon carbide, borazon, various alumina/zirconia types, diamond, cerium oxide, and a host more depending on the specifics of your appication. as cheap as industrial diamond tools aer- its an easy way to go and can be used on various types of glass. not recommended for all but still usable for the unusual task with proper technique management.

[awright]

But I believe that some tempered glasses are under stress at the surface so that even the most gentle cutting action can disrupt the stress distribution and lead to shattering. I believe that auto side window glass is of this nature.

awright

[Brett]

Originally Posted by awright

But I believe that some tempered glasses are under stress at the surface so that even the most gentle cutting action can disrupt the stress distribution and lead to shattering. I believe that auto side window glass is of this nature.

awright

You are correct Awright
No toughened glass can be cut or drilled after the toughening process. You can at times polish an edge but it is risky.
The surface of toughened glass is in compression and the body in tension, pierce the (for want of a better word) zone of contaflecture and you will have whats called "Catastrophic failure" ie your sweeping up glass