Do you need to complete a craft project or home repair that involves drilling a hole in the glass? You can do this with a regular electric drill, as long as you use the right bits. The trick is to use a harder material than the glass itself.
Steps
Part 1 of 3: Getting the Right Equipment
Step 1. Evaluate what type of glass you need to drill
You can drill a hole in a wine bottle, aquarium, mirror or glass tile - basically any type of glass. However, you need to remember that the general rule is never to drill into toughened or safety glass.
- The tempered glass shatters into a thousand pieces on simple contact with the drill bit. To understand if the glass in front of you has undergone this kind of treatment or not, look at the four corners. Manufacturers typically engrave hardened plates at the corners.
- You have to consider another factor: when using the drill you should not wear loose dresses, pendants, bracelets, necklaces or shirts with long fringes. You must make sure that no items of clothing or accessories can get caught in the instrument, and you should also wear protective goggles.
Step 2. Purchase a drill or use the one you already own
If you already have an electric drill, it is probably a perfectly suited tool for your purpose. If not, buy a normal drill, the kind you can buy in DIY stores.
- You don't need a special tool to drill the glass, just the specific tips.
- For this operation you do not have to operate the instrument at maximum power, otherwise you could break the glass. Imagine having to slowly carve each layer of glass instead of drilling a hole. This will slow down the process.
Step 3. Choose the correct tip
For this type of work you need special tips that are intended only for glass. This is a fundamental detail, you cannot use the first tip you find in the toolbox. Ask the hardware store clerk for some information, in this way you will be sure to buy the right accessory. Glass bits are very common, so much so that you can also buy them online.
- Among the various possibilities are the tungsten carbide tips that are used to drill glass and tiles. They have a tip with a particular shape that resembles that of a spade or an arrow and are built to resist the friction generated by glass and ceramic.
- This type of drill is typically found in all hardware stores and DIY stores. You just have to go to the tip shelves or ask the clerk. But remember that very cheap ones easily lose their thread or can even break.
Step 4. Use a diamond tip
This kind of accessories can pierce ordinary glass, sea glass, wine bottles, glass blocks and other hard materials such as stone and marble. Diamonds are harder than glass, so they are perfect for cutting this material.
- The diamond tips allow you to create holes with a diameter of 6 mm or even larger; they are available with rounded ends or for small cores. In addition, they leave the edges smooth and clear and are the first choice when drilling the glass. You can use them for many holes and they rarely cause breakage if used correctly.
- If you need to drill a very small hole, choose a small diamond tip with a solid end that is both flat and pointed. You can find even very small diamond tips, with a diameter of 0.75mm.
- You can also purchase a diamond hole saw. In this case you need a drill equipped with a quick release keyless chuck. It is a piece to be fixed to the drill that allows you to create a first hole in the glass. Then you can mount the hole saw on the drill, place the tip in the pilot hole you made earlier and continue with the cut.
Part 2 of 3: Prepare the Drill
Step 1. Place the glass in a small container if possible
You can use an ice cream jar or a plastic tray for photo developing. You must avoid drilling into the table or work surface.
- Place newspaper on the bottom of the container to protect it from the drill bit.
- Alternatively, you can place the glass on a very flat surface that gives it maximum support. If you can, insert a rubber mat or other similar cushioning element under the glass. However, remember that it must be well supported and perfectly flat. In other words, don't drill through the glass while hanging it or in other similar positions.
- You have to constantly pay attention to safety. Make sure there are no elements that you could damage while working and that the power cord of the drill is not near water sources.
Step 2. Attach a small piece of thick cardboard or masking tape to the glass
This prevents the tip from slipping at the beginning of the work. You can use a piece of cereal box for this.
- Alternatively, you can glue a piece of paper or packaging tape to the right and back of the glass where you intend to drill. This prevents splinters from forming.
- Draw a reference point on the masking tape so you know where to place the drill bit. This will guide you through the whole process.
Part 3 of 3: Drill the Hole
Step 1. Start drilling the glass by setting the drill to minimum speed
You have to move much slower than when you pierce other hard materials; you can find online tables showing the correct speed for each type of material, including glass.
- Insert a small bit into a variable speed drill. Make sure it is securely locked. It is worth starting with a 3mm or 2mm tip. First you only need to create a small depression.
- Afterwards, you can remove the cardboard or tape and increase the speed of the tool to about 400 revolutions per minute. If you overdo the speed, the tip may leave some burn marks. If you find it necessary, switch to a larger drill bit to enlarge the starting hole. The first hole is called the "pilot" hole and will guide you through the next steps, which involve the use of larger-gauge bits to complete the job.
Step 2. When the bit is about to completely pierce the thickness of the glass, you need to slightly decrease both the pressure applied and the speed of the drill
When you pierce the glass, you must always set the tool at a low or medium speed, but you should reduce it further as you approach the opposite surface of the glass, as it is very fragile and you risk breaking it.
- If you apply too much pressure, you can break the glass. Keep the drill so that it is always perpendicular to the glass surface to avoid chipping. If you have never done this work, always use minimal force, so you avoid making serious mistakes.
- Alternatively, you can puncture the glass up to half its thickness and then (carefully) flip the material over and resume drilling on the other side until you have completed the opening.
Step 3. Use coolant to prevent the tip from overheating
This detail is very important. Pour some oil or water on the area you are drilling (water is the most common choice). If the surface is particularly tough, you will need to add more coolant. The liquid lubricates both the tip (or hole saw) and the glass, cooling them both. If the temperature rises excessively, the material may crack.
- The coolant should be applied before and after the operation.
- You could fill a bottle with a small hole with water so that the liquid falls on the tip and the glass as you work, cooling the area.
- You can also vaporize the water on the glass and tip to ensure adequate lubrication. Again remember to be very careful with the power cord of the drill. Put some water in a spray bottle and apply it as you work. If a white powder forms during the process, add more water and decrease the turns of the drill.
- Consider putting a wet sponge under the glass as you pierce it, so you can cool the area. Alternatively, you can pour a little water on the surface before starting work; in practice you should put the piece of glass in a container that contains a little water.
Advice
- Do not run the drill at excessive speed. Glass is a very hard material with a high abrasive action capable of ruining the tips quickly.
- Use a series of points starting with the smallest and gradually increasing the gauge to reduce the pressure on the glass.
- If you use a drill press you can adjust the pressure of the tip on the glass.
- Be very careful because the drill can leave splinters around the edges of the hole and on the other side of the glass while, on the entry side of the bit, you will get a clean and precise hole.
- While it is a better solution to use water, you may want to consider using oil to lubricate the tip; use only in minimal quantities.
- Cool the glass as you pierce it, so you avoid breaking both tools and the glass itself.
Warnings
- Glass is very fragile and sharp. Handle it carefully, wear gloves, and when drilling, use a respirator and safety glasses.
- Splinters of glass are extremely dangerous for the eyes, you should always use glasses that comply with EN 166.
