Cabochons are commonly used in jewelry to make decorative necklaces, earrings, bracelets and more. They are non-faceted gemstones found mainly in oval and dome shapes. Due to the fact that there are numerous ways to incorporate cabochons into jewelry products they typically do not come pre-drilled. In order to be able to customize a cabochon, or drill the hole where you want it, you are going to need to master the drilling technique. It make take a few trial runs before you are able to master drilling holes in cabochons, or cabs, but it is not too difficult of a technique to learn.
First and foremost safety is important when dealing with any heavy-duty machinery, such as drills, as well as when the item you are working with can splinter or shard and end up in your eyes or being inhaled. Find a pair of comfortable safety glasses that do not limit your vision and you are ready to get started. If you are concerned about the dust or debris that comes from the cabochon when you are drilling you can find simple masks at any hardware or craft store.
Another important tip for drilling holes into or substance, or actually just using a drill in general, is to remember that the drilling process itself creates friction, which creates heat. Drill bits can get so hot during a drilling process that they break; if you are spending a decent amount of money on jewelry sized specialty drill bits you definitely are not going to want them to break every single time you try to drill a hole in something. To ensure that what you are working on stays cool enough, hold the cabochon under water, a glass bowl will work, while you are drilling it. Be sure that if you’re using an electrical drill that you do not get any of the motorized parts wet since that could either short out your entire drill or electrocute yourself. One other nice thing about drilling in a bowl of water is that the dust and debris that comes from the drilling is not sent into the air and also makes it easier to clean up when you are finished.
The next step is to mark the cab where you want to drill. Be sure when you are marking that you do not drill too close to the edge of the cabochon. This can cause the piece you are working with to splinter or break in half entirely. The next step is to select the drill bit you are going to use. I would recommend using a diamond drill bit, just because they are high quality and cut just about anything with ease. Other jewelry bits work just as well though. Find a bit that is of an appropriate size for the hole you are trying to drill.
Finally you are ready to start drilling. You can use either a hand drill or a drill attached to a stand (these tend to be stable and can reduce drilling errors). I would suggest drilling a small amount and then pulling the drill out before repeating the process as many times as it takes to get a nice clean cut all the way through the hole. This gives both the bit and the cabochon a chance to cool off as well as eases the pressure. Rinse off the cabochon and you are finished!