Drilling Glass and Stone -
Hello and Thank You for taking the time to read my brief description on drilling glass, stone, beads. I have been at this game for over 35 years and have drilled most every material in that time.
If you are drilling beach glass or any hard or soft stone. you will need diamond tipped drill bits or diamond reamers. For the drill bits I would suggest a 40 grit 30 piece drill bit and tip set to begin with. 40 grit is very coarse and will cut faster so is perfect for drilling holes. I also like a 20 diamond twist drill set for drilling very small holes, (1mm and under), and 10 bit sets for larger size 3mm holes in pendants. I suggest beginners should start with the bigger bits so you can experiment at what works best for your application. Wood carvers also love these bits for carving wood, bone, antler, metal, etc.
You can use these bits in a flex shaft drill or any variable speed hand drill. Most homes would have the latter, or you could use hand held reamers with handles. These will take a bit of effort and I would only recommend if you only have a small amount of hole enlarging or smoothing to accomplish. Otherwise an electric drill is the easiest to work with.
Just know the hole you drill using a 40 grit diamond bit is going to be rough. You drill quickly but the hole will be rough inside so you might consider using a medium grit bit afterwards like a 150 grit diamond bit to smooth the holes roughness. If you are stringing on flex wire you probably will not need to smooth the inside of the hole. If you are stringing on silk thread or nylon thread you should follow up with the 150 grit bit.
Get real serious about proper protection for yourself from the materials you will be coming in contact with. Glass, stone, shell, and bone in powder form are dangerous. You should never breath the dust you will create working with these materials. Use eye protection with side covers. Get in the habit of using a respirator osha rated for jewelry applications. This respirator should not only cover your nose but you mouth as well, and use it whenever drilling or polishing any materials. I always follow up with a full face shield as additional protections agains flying debris in this type of profession.
Older eyes may require a bit of help, I like a jewelers visor which gives me up to 2.5x the magnification for small work. Or there is a great magnifier called a 3rd hand magnifier. Also the old time jewelers loupe is great for finding hallmarks on jewelry and inspecting prongs on jewelry and inspecting unset stones.
Next, you might ask yourself.. how do I hold onto the item I wish to drill? I like a bead holder jig, which will hold round beads between 4mm and 12mm diameters. For flat items I like a pressure grip jig.
Buy a full size apron and wear it to protect your clothing from dust particles. Leave all your protective gear in your work space so as not to contaminate your family and regular living area.
Drilling Under Water -
No you don't need diving gear for this! I like to drill glass or semiprecious stones by holding the item under water. Put the piece into a shallow container like a clean tin lid of a mayonnaise jar. Be very careful because the combination of water and electicity (drill) is very dangerous. Hold onto the glass shard, (or item to be drilled), with your left hand and holding the flex shaft handle (or variable speed drill) with a diamond tipped drill bit in your right hand. Insert the drill bit tip (ONLY) through the water and drill the shard or stone, (you only need enough water to cover the shard laying on its side). Drill slowly at first and allow the tip of the drill bit to seat and then adjust your drilling speed once the hole has started. You may need to change the water frequently as the powder generated by the drilling will cloud the water. I like to drill very slowly because the drill bits last much longer that way. I also like to drill half way through the piece on one side and then flip it over and drill through to meet the hole from the other side. This also prevents the hole from blowing out or shattering on the other side.
I hope this helps you to solve your drilling problems. Remember, drill slowly and you will not only save your drill bits but also the piece you are working on. You will be able to drill several holes with one bit once you get the hang of it. Don't expect to get more than one hole drilled per bit in the beginning. Practice makes perfect.