Sometimes you have a bottle that just doesn't have enough holes in it. That one at the top comes in handy and has it's purpose, but sometimes you just need a hole on the side of your bottle. In this instructable I'm going to give some tips for drilling some of those extra holes into glass bottles.
I also made a video of the process, which you can watch here: https://youtu.be/vruWpGb5248
Step 1: Choose Your Bit
There are 2 common type of drill bits for drilling holes in glass:
Diamond bits have a rough, flat, hollow tip. Carbide bits look more similar to a regular drill bit with a pointed tip. Personally, I prefer the diamond bits. I'm going to show 2 different techniques that you can use with either type of bit.
Step 2: Practice!!
If you haven't drilled holes in glass bottles before, I recommend practicing a few times before drilling into the bottle you want the hole in. With both of these types of bits, it's better to think of it as not drilling through the glass, but instead sanding or grinding through the glass. It's easy to use too much pressure and messing up the hole that you want to make. Sometimes when you break through the glass, the drill can bump the bottle and make the hole too big. Another thing that can happen with too much pressure is blowout on the inside of the bottle. The diamond tipped bits can drift easily while starting the hole. And sometimes the carbide bits will catch onto the glass and crack the bottle when breaking through. But with practice, you can get a good hole with either type of drill bit.
Step 3: Have Your Water Ready, Gotta Keep Things Cool
When drilling through glass, it's important to have a constant supply of water where the bit is being used, and this is how I'm going to do that. I'm going to start with this plastic bottle. It helps to have the cap, but it's not absolutely required. Poke a hole near the bottom of the bottle with a push pin. I'm using this bowl to catch the water, because I don't want to make a mess. Fill the plastic bottle with water. With the cap on tight, the water will stay in the bottle. If you take the cap off the bottle, water will come out in a stream. You don't actually need to take the cap all of the way off, just loosen it a little. Then to stop the stream, just tighten the cap.
Step 4: Drill the Hole: Diamond Bit
Get your glass bottle, start the stream of water, and have your drill ready. This first hole will be with the diamond tip bit. It can be tricky holding the bit steady as it starts, but if you start drilling at a 45 degree angle that will make it a little easier. As the hole gets deeper, you can move the drill bit more vertically to go straight in. Keep an eye on the water stream and make sure there is a constant flow where you're drilling. Sometimes you'll see cloudy water start to flow inside of the bottle when you're close to breaking through. Remember to not use much pressure, or you could have some glass blowout in the bottle or even some other damage. This one looks pretty good.
Step 5: Drill the Hole: Carbide Bit
Next I'm going to use the carbide bit. Since the tip has a point, unlike the diamond bit, you just drill straight in. Just like before, you want to keep the water flowing on the bit. Also keep an eye on the water level in the plastic bottle and top it off as necessary. This time I used too much pressure, and when I broke through the glass the drill bumped into the bottle. There is some glass blowout in the bottle, and some cracks too.
Step 6: Drill the Hole: Diamond Bit With Support
Next I'm going to show another method for using a diamond bit to help hold it more steady when starting the hole. You'll need a regular drill bit the same size as the diamond bit you're using. You will also need some firm, but flexible plastic. The plastic that's used to make buckets is perfect for this. Drill a hole in the bucket and cut out a piece around the hole. A benefit of using plastic from a bucket is that it's curved, which helps you using it with the bottle. You'll want to tape the plastic to the bottle, just make sure to use enough to hold it securely. It helps to remove the tape from just around the hole in the plastic. Use the same setup with the water flowing where you're drilling. Start drilling through the hole in the plastic. This time when you drill into the glass, you do not need to start at a 45 degree angle, just start by going straight in. The plastic will hold the bit in place and keep it from drifting around. Once you break through, remove the tape and examine the hole. The results that I got with this are similar to the other hole I made with the diamond bit.
Step 7: Drill the Hole: Carbide Bit With Support
If you're using a carbide bit and you're struggling with holding it in place, you can use the bottles label or a piece of tape to help keeping it from drifting. This time I'm not going to drill all of the way through the bottle, but you can see that I was able to get it started and made a good dimple.
Step 8: And That's It!
That's how you can drill holes into glass bottles. Remember to practice and get a feel for the process so that you can drill your holes without the unwanted results. If you have any tips or advice on drilling holes in glass bottles, please, leave a comment telling us about it.