How to Drill Sea Glass in Under 50 seconds by Eternal Tools

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.

How to drill sea glass, or how to drill glass - the principles and tools are all the same.  Sea glass, or beach glass, is relatively small, so you will use smaller drill bits than if you are drilling other types of glass, but other than that, the same rules and methods apply.

Read on and follow along with me to find out how easy it is to start drilling sea glass and beach glass, and other small pieces of art glass.

What You Will Need to Drill Sea Glass:

  • Sea Glass (this method can also be applied to beach pottery and other small pieces of glass)
  • Marker pen or Chinagraph pencil
  • A rotary tool such as a Dremel (I am using a Dremel 3000) with a Flex Shaft or drill press (optional) 
  • Diamond Drill bits (I'm using a 2mm small diamond core drill in these images, but a 2mm small Diamond drill bit with a solid end will work just as well, if not better, as they have a larger surface area and will therefore last longer, and are more robust)
  • Collet or adjustable chuck such as the Dremel Multi Chuck to hold the small diamond drill bits
  • A shallow dish such as a plastic food container, sandwich box or ice cream tub
  • Piece of wood to rest your material on as you drill
  • Water (acts as a lubricant and helps 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

Buy a Diamond Drill Bits Set For Your Dremel

What Size Diamond Drill Bit to Use for Drilling Sea Glass

The size of the drill bit you choose to use will depend on what you'll be using the drilled sea glass for. 

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 will need to know the width of your keyring fitting to make sure you drill a big enough hole.

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 an even larger size try the diamond core drills - these are available in sizes from 3.5mm - 60mmm.  The sizes from 4mm and up require the use of a standard household drill (check the technical tab on the product page for shank sizes, dimensions and specifications) 

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 the different sizes.

Take a look at the Small Diamond Core Drills

Small Diamond Drill Bits or Small Diamond Core Drills - Which should I use for Drilling Sea Glass?

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 or beach 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 or beach 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

Drilling Sea Glass by Eternal Tools. The tools you need and how to drill seaglass

1. Mark your sea glass where you wish the hole to be with your marker pen or chinagraph pencil.

2. Set up your water tray by placing your piece of wood into the tray, placing your pebble on top and pouring 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 or molten beeswax)

3. Select your drill bit and attach it to your Multi Chuck (see the video below 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 halfway. 

Helpful Note: It is possible to drill halfway through one side of the beach 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 holes 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 them 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 as they are 100mm long.


Before we start, let's ensure our working area is clear and free of clutter. 

When using a drill, always ensure there's nothing around that will get caught in your lead or that you could knock with your elbow. 

Wear an apron and long or short sleeves, but no floaty sleeves!

If you have one, using a stand with a flexible shaft can help to keep things tidy and out of the way of your working area a little bit better.

Warning. 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 with a safety thermal cut-out to prevent overheating.

Keep an old cloth or tea towel on hand to ensure your drill, working area, and hands stay 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.

  • Mask
  • Safety Goggles
  • Apron
  • Extra vigilance around water and electricity

Step 2. Drilling Glass

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 its slowest speed setting.

2. Angle your drill at roughly 45 degrees and take the drill to your beach 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. 

Drilling at an angle to make the initial cut helps prevent the drill bit from sliding and skittering across the surface of your beach glass.

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 the above video was 4mm thick 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 halfway through and follow steps 1 to 3 again.

How to Drill Sea Glass using a 1.5mm small diamond core drill from Eternal Tools

Step 3. Finishing and Further Ideas for Sea Glass

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 its natural form with all its irregularities. However, I often have a piece that I just wish I could slice off the top, or remove a little bit. 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 or crystal 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 crystal. A carbide hart bearing cutter is useful if you are using Swarovski crystals.

Making a Drilled Hole Larger?

If you've drilled your hole and then discovered 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. 

Sea Glass Jewellery Making

Design ideas are plentiful when it comes to sea glass jewelry and once you've mastered the different methods, preferably on a piece of practice glass first, you can turn sea glass into unique pieces of jewellery.

Here are some jewelry making ideas for you:

Sea Glass Beads

Making sea glass or beach glass beads is a fun idea to experiment with using all those different techniques you've now learnt and with all the varied pieces of different sea glass colours you might have in your collection.

You can either use the sea glass pieces in their original form or use a diamond bead shaping concave burr to carve the pieces into a more spherical shape. 

Edges can then be smoothed and polished using first a diamond file to remove rough edges and deburr, then polished to a professional finish using EVE Diapol Polishers or diamond polishing paste.

Once you have your beautiful sea glass beads, each bead can be drilled using diamond drill bits to hold your own bail, links or leather cord.

Sea Glass Pendants

As you've now discovered, a piece of sea glass can be drilled to make sea glass pendants by either threading cord or leather through the drilled hole or by attaching a jump ring, necklace chain and lobster claw to make sea glass necklaces.

If you'd like to try wire wrapping sea glass you will need some flat nose pliers, round nose pliers, and a pair of wire cutters. You will also need some sterling silver jewelry wire or beading wire to hold the piece of glass securely. This can then be used to make sea glass earrings or a pendant necklace.

Bezel Setting Sea Glass

Sea glass jewelry designs that involve bezel settings and link settings can securely hold the sea glass in place, but first, you will need to flatten off the back of the sea glass and possibly around the edges to have it sit flat, and flush within the setting. 

Grab yourself a diamond file or a diamond hone (which is even better as you can run the piece of glass along it) and grind away the bottom of the glass until it sits flush. 

If the piece of glass is particularly lovely in a certain area but has been chipped in another you could always cut off the chipped area using some diamond wire as mentioned above under 'Cutting Sea Glass'.  

For teardrop or other odd-shaped pieces of sea glass, use a bell cap.

Silver metal clay can be used to make your own settings.

Embellishments To Your Beach Glass Jewellery

As mentioned previously, you can embellish your pieces of beach glass by using a small diamond ball burr or a diamond countersink burr to create a concave area within which you can glue a tiny Swarovski crystal using G S Hypo Cement.


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 to 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