Disclaimer. Using rotary tools near water has never been, to the best of our knowledge, endorsed by any of the rotary tool manufacturers. If you do choose to drill near water or with attachments under water connected to your drill then you do so at your own risk. Please be aware that mixing electricity and water can be very dangerous.
What You Will need:
- Sea Glass (this method can also be applied to beach pottery and other small pieces of glass)
- Marker pen or Chinagraph pencil
- Rotary tool such as a Dremel (I am using a Dremel 3000), with Flex Shaft or drill press (optional)
- Diamond Drill bits (I'm using a 2mm small diamond core drill in these images)
- Collet or adjustable chuck such as the Dremel Multi Chuck to hold the small drill bits
- Shallow dish such as a plastic food container or sandwich box
- Piece of wood to rest your material on as you drill
- Water (as a lubricant for your drill piece and to keep your drill bit and glass cool whilst drilling)
- Safety goggles and mask
- Old cloth or tea towel to mop up any water or debris
What Size Diamond Drill Bit to Use
The size of the drill bit you choose to use will depend on what you'll be using the drilled sea glass for. Sounds obvious, but it's one of the most popular questions we get asked.
Have an idea in mind before you start your project as to what you will be doing with it once it's finished. For instance, if it's going to be a keyring, then you need to know the width of your keyring fitting to make sure you drill a big enough hole.
As an idea, I tend to mostly use 1mm, 1.5mm, 2mm and 3mm for jewellery work.
If you need a larger hole than 3mm try a Bottle Neck Diamond Core Drill. These will also fit into your hobby rotary tool or pendant drill. They have a shank size of 2.35mm.
Helpful note: The shank is the bit that goes into your drill and the working end is the end with the diamonds on that you will use to drill with
If you need larger still try the diamond core drills - these are available in sizes from 3.5mm - 65mmm but require the use of a standard house hold drill (check the technical tab on the page here for shank sizes)
If you're at the experimental stage why not try a Diamond Drill Bits Set for your Dremel,. This little kit contains the Dremel Multi Chuck which is mentioned above under the list of what you will need, along with a variety of 4 diamond drill bits - 2 x solid ended small diamond drill bits and 2 x small diamond core drills, all of different sizes.
Small Diamond Drill Bits or Small Diamond Core Drills - Which should I use?
Small Diamond Drill Bits have a solid end and therefore a larger surface area so they last longer than the small diamond core drills, but may take longer to drill a hole. They are more robust and therefore ideal for very tough, dense pieces of sea glass.
Small Diamond Core Drills are hollow and allow water to flow up and around inside the drill bit as you drill. They will drill a hole quicker than the small diamond drill bits, but may not last as long because they have a smaller surface area.
If you regularly drill sea glass then it's worth having a combination of both small diamond drill bits and small diamond core drills as sometimes you don't know if you have a very tough piece of sea glass until you start drilling!
Step 1. Setting Up
1. Mark your sea glass with your marker pen or chinagraph pencil where you wish the hole to be.
2. Set up your water tray by placing your piece of wood into the tray, place your pebble on top and pour water in until the glass is covered by about a centimetre of water. (Optional: you can hold the sea glass in place with a bit of Blu Tack)
3. Select your drill bit and attach it into your Multi Chuck (see the below video if you need help with this) making sure there is enough of the drill bit exposed so that as you drill into the glass the water doesn't touch your chuck or any part of your drill. I usually have the drill bit in about halfway.
Helpful Note: It is possible to drill halfway through one side of the glass, flip it over and carry on drilling through the other side. If this is your preferred method then you will need to measure the glass to find out where the entrance and exit hole will be so that they line up.
To do this, take two pieces of cotton. Wrap the cotton around the sea glass so that they cross. Where the crosses meet on the top and underside of your glass, mark with your pen.
This method is ideal if the depth or thickness of your pebble or stone is bigger than the length of the drill bit. Our 3mm extra long diamond drill bits will also solve this problem.
Before we start, lets make sure our working area is nice and clear, and free of any clutter. When using a drill, always make sure there's nothing around that will get caught on your lead or that you could knock with your elbow, and no floaty arm sleeves or scarves please!
Warning. It goes without saying that you should always be extra vigilant when using water near a drill. On this particular occasion I had my drill plugged into an extension lead that comes with a safety thermal cut-out to prevent overheating.
Keep an old cloth or tea towel to hand to ensure your drill, working area and hands stays dry at all times. No touching electrical appliances with wet hands!
Furthermore, as you drill into your seaglass make sure the drill bit is always far enough out of your chuck so that the chuck or drill doesn't touch the water.
And lastly, please wear your mask and goggles and make sure your working area is nicely ventilated.
- Safety Goggles
Step 2. Drilling
1. Whilst keeping your sea glass immersed in the water and holding the glass either with your fingers (please be careful) or a clamp or vice of some kind, start your drill on it's slowest speed setting.
2. Angle your drill at about 45 degrees and take the drill to your glass and make an initial cut . As soon as this cut has been made, slowly move your drill into a vertical position and continue to drill, always on the slowest speed setting and with very little pressure. Let the drill do the work. By drilling at an angle to make the initial cut this helps to prevent the drill bit from sliding and skittering across the surface of your stone.
3. As you drill, occasionally move the drill bit up and down to let in some water. This will help the water flow in and around your drill bit and wash out any debris. This will also help to keep the drill bit and your glass cool. Overheating can cause the diamonds to dull or come off the drill bit and the glass to crack.
4. The piece of sea glass in this picture is 4mm in thickness and took under 50 seconds to drill using a 1.5mm small diamond core drill.
IMPORTANT: Please don't be tempted to speed up your drill or apply further pressure. Some sea glass will take longer to drill through but speeding up the drill or applying more pressure will shorten the life of your drill bit by dulling or burning the diamond grit off. You will make a hole eventually, so patience is the key!
Note: If you are using the method whereby you flip the sea glass over and begin drilling again from the other side, do so once you've drilled about half way through and follow steps 1 to 3 again.
Step 3. Finishing and Further Ideas
Carve a shape into your sea glass
Once you have mastered the skill of drilling a hole through a pebble or sea glass you can begin to get creative and start to carve and engrave designs into them such as a heart. Our popular article 'How To Carve Hearts in Pebbles & Sea Glass' shows you how!
Cutting the Sea Glass
I love to use sea glass in it's natural form with all it's irregularities. However, I often have a piece that I just wish I could slice off the top, or remove that little bit that is in the way. This can be useful when you want it to fit into a setting for instance. With the help of diamond wire hand saw blades you can do this. Have a read of this tutorial article to find out more 'How To Easily Cut & Shape Sea Glass and Stones Using Diamond Wire Hand Saw Blades'
Inlay a gemstone into the Sea Glass
Using a small diamond ball burr you can carve a 'dip' into your sea glass so that you can inlay a small gemstone or Cubic Zirconia.
Making a Drilled Hole Larger?
If you've drilled your hole and then discover it is not wide enough, don't despair, you can always expand the hole size by using a diamond twist drill.
These twist drills have diamond grit that is bonded vertically up the shank of the drill bit so they're perfect for expanding hole sizes that have already been created, the flutes grind away at the insides of the hole to make the walls of your hole wider.
Helpful note: Do not use a diamond twist drill to make a hole, they are not manufactured for this purpose. Only use these for expanding an existing hole.
We hope you enjoyed this tutorial, and hope it inspires you to get creative and to start drilling sea glass! We would love to see any finished pictures of projects you've embarked on, please send them into us.
For further help, you might also like to read our articles:12 Things you Should Know about Diamond Drill Bits and What is Sea Glass? How to Find Sea Glass