Shattered glass. A glassworker’s greatest nightmare. And, if you’ve ever worked with glass, not something particularly rare. You need to be extremely careful with glass, especially when you are drilling.
Drills have a reputation as tools to break through tough, hardy materials. So why are we using them to cut through something as fragile as glass?
Well, with decent preparation, you can do it. So, how to drill a hole in glass?
By using one simple yet fancy-looking drill bit, you can cut through glass easily. Investing in a diamond hole drill bit (or, even better, several diamond hole drill bits) will let you drill through glass, ceramics, and minerals like quartz with no trouble.
If you can make my easy-to-build jig and get the correct drill tip, you will be able to drill through anything made of glass. This doesn’t just mean panes of glass. Curved glass and uneven surfaces will be cut just as well.
So let’s get started.
How to Drill a Hole in Glass?
Gathering Your Equipment
As I’ve already said, this is a job which needs specialist equipment. You can’t do this job with a regular drill bit. Those drill bits are simply too flat and will crack the glass before you can get any hole starting to form.
If you want, you can find glass-working bits. These are similar to masonry bits, but they are particularly sharp. With steep tapering, the drill bit can start a hole and slowly expand it (instead of rubbing an entire drill bit head against a substantial portion of the glass). If you have one of these drill bits, try to use it with a spare piece of glass. We won’t be talking about these tips, however.
Because there is an easier way.
We’re going to use a diamond hole drill bit. This looks a bit like a cup with diamonds around the rim. By using this kind of drill bit, we’re going to instantly start cutting a hole when we make contact.
This might seem strange, but this spreads the pressure. Unlike a drill bit with a sharp tip, where we put all the pressure on one point, we are spreading it out. This stops cracking and shattering.
You will need:
- A piece of glass (curved or flat)
- A drill
- A diamond hole drill bit
- A piece of wood for a jig
- A lubricant like water
- Safety gear such as goggles and a dust mask
When you have all that together, we can make sure that we are safe to start the drilling.
I’ve already said it. Glass can be dangerous. Not only is it temperamental, but it is also a real health hazard when it cracks or smashes. If you crack a piece of glass, any part of your body that is facing the glass is at risk of getting cut or stabbed by the shattered glass. Dangerous! This is why safety is so important.
If you are unlucky enough to shatter a piece of glass, it can seem to explode. Pieces will fly in every direction and you will be at serious risk of injury. This is why you will need to wear goggles when using a drill to work with glass. If a piece of glass goes into your eye, you are at dire risk of suffering from serious, serious damage.
Similarly, you will need to protect your body. You won’t need to use a kevlar vest. It is a good idea to wear something that covers your skin and is thick enough to offer some protection. This could be a thick wool jumper or a similar piece of clothing.
A pair of decent, fitted gloves. These need to cover your fingers and hands, so finger gloves are no good. You must also make sure that they are not loose. You are using a drill! Moving parts can cause loose clothing to get caught. This can lead to serious injury.
As glass can spit off lots of tiny shards when drilling, a dust mask is key. You don’t want glass in your lungs. Protecting your body will prolong your career and protect your health. Don’t cut corners with the safety of your body.
Make a Jig To Cut Glass
Jigs are great, but not a lot of people know how to make one for cutting glass. Truth be told, all you need a piece of wood. Any scrap piece will do, but it needs to be small enough that you can hold it on top of the piece of glass.
With your diamond hole drill bit, cut into the scrap piece of wood. You want this to be the same size as the drill bit itself. When you have made an appropriate cut through the wood, you may need to take a small file or a piece of sandpaper to the edges.
You want the drill bit to easily fit through the hole. This will help you keep a straight line when you make contact with the glass. If you slip with a spinning blade, you can expect that the glass will chip, crack, or even shatter.
This jig needs to be small and thin enough to lay over the glass you are cutting. Don’t use a 2×4. It’s a waste of wood and you’ll probably cause damage to the glass by using such a heavy piece of equipment.
Preparing Your Workspace
Now you are prepared and safe, you can start to cut. Make sure you clear all unnecessary equipment or spare materials from your workspace. You won’t have to move much to cut glass, but it is always good practice to get rid of tripping hazards.
You will need to keep your glass secure when drilling into it, but clamps aren’t an option. It is too easy to overtighten the clamps and shatter the glass.
Using a scrap piece of wood underneath your glass will give you a sturdy base. I have seen people use small stickers to hold the glass in place when on the wood. But I find that holding our homemade jig onto the glass will stop it from going anywhere.
A handy tip for cutting curved glass that I’ve picked up is using a towel. By placing a towel on a work surface, you can place the glass into a divet you make. When it is in the divet, it can’t roll as much.
Starting To Cut The Glass
Using the jig, place your diamond hole drill bit over the glass. You want it to start spinning before you make contact. If it isn’t spinning, the pointed diamonds can cause the glass to crack. Don’t mess it up at the first step.
When starting a cut, we only want the drill to be spinning slowly. This is good general drilling advice, but it is especially important for glass.
Slow cuts are great for glass as it allows the diamonds to gently cut into the glass without shattering it. If you go too fast, the drill bit will drag along the glass and scratch it. Although scratched glass can be saved, it also increases the chances of cracking the glass. Take your time.
Throughout the cut, you will need a lubricant to apply to the glass and the drill bit. How you apply this is up to you, but squeezing a sponge over the drill works just fine for me.
It is important to lubricate the glass as heat will build up if you don’t. Heat is really bad news as it can cause sections of the glass to expand and, in turn, cause the entire plate or piece to shatter. Take your time, apply lubricant, make a great cut.
The biggest difference between cutting glass and cutting another material like quartz with a diamond hole drill bit is that you can’t use pressure.
Don’t use any pressure at all. We want the glass flat so that we can take advantage of gravity. Gravity will apply enough pressure onto the glass to cut. If you press down, you are just increasing your chances of shattering the piece.
Cut The Glass
As you work through the glass, start to gently rotate the drill. By making gentle circles with the drill, we are encouraging the diamond drill bit to cut into the glass further.
This speeds up the drilling process, uses more of the drill bit, and reduces the chances of dulling your diamonds. This is good in the long run as it means saving on replacing bits every time you drill into glass.
If you are working through a particularly thick piece of glass, you might want to pull the drill bit out and allow for the glass to cool down.
This is fine if you need a break, but try to avoid removing the drill. Getting the drill back into a hole in a piece of glass is more difficult than it looks. You are creating a risk that you will chip the edges of the hole and give yourself a considerable headache later on.
When exiting the glass, you want the drill to be very slow. This is less important if you have some good support underneath (such as a piece of spare wood), but it can still improve the quality of the job. Just like starting the drilling, you need to be slow.
This will cut down your chances of burrs or chips that will ruin the quality of your job. It also saves on annoying cleanup jobs after. Slow and steady will give you a fantastic piece of glasswork that you can sell, display, or use wherever you want in your home or business.
When you have broken through the other side, remove the jig. Now you can see your finished glass piece (and inspect for cracks).
Is drilling glass scary? A little. Is drilling glass difficult? Not if you know the right way to do it. All you need is the correct tools and you can make an excellent drilled hole in any piece of glass. If you have a curved piece of glass, you can still follow the tips above.
Using a jig isn’t necessary if you are experienced with drilling glass and have a steady hand. For the first fewer goes, however, I would say that a glassworker needs it. It will make the job a whole lot easier and will give you excellent conditions for making the best holes you can.
Remember, patience is almost more important than technique when dealing with glass. Being too hasty or too heavy-handed can lead to broken glass and potential injury. Protect yourself.
If you have any questions about how to drill through glass then let us know in the comments. Before you go — here are some frequently asked questions about drilling through glass.
FAQs About Drilling Through Glass
Can I Drill Into Curved Glass?
Yes. Use a jig and you will have no trouble getting your diamond hole drill bit to cut the glass cleanly. If you don’t use a jig, you run the risk of dragging the bit across the glass and shattering the whole piece.
Can I Drill Into a Piece of Glass Without a Lubricant?
No, or at the very least you shouldn’t. Drilling into glass creates heat. The heat from the drill will increase the chances of the glass shattering, ruining your job, and wasting time, resources, and money. Use a lubricant and save your pennies.
Do I Need a Diamond Hole Drill Bit to Drill Into Glass?
No, other specialized drill bits are excellent for cutting into wood. These are extremely pointed and look more like spear tips than conventional drill bits. They bore into the glass on a very small surface area – this decreases the chances of shattering or pulling against the glass.
How Can I Secure Glass When I Am Working on It With a Drill?
This can be tough. Depending on the size and shape of the glass, you may just have to get something that stops it from moving as best you can. I like to use a towel when cutting round glass as it means it can’t roll. Experiment with a few things and find out what works for you.