Thoroughly saturated terra cotta clay is easier to drill through. Water acts as both a lubricant and a cooling agent, which makes it easier for the drill bit to work its way through without causing damage to the clay or overheating. When you are ready to drill through the clay pot, remove it from the water and allow any excess puddles of water to drip off the surface you’ll be drilling through.
The drill bit size and number of drill bits you’ll need will vary based on the size of the hole you want to create. If you want to create a simple drainage hole, you’ll probably want at least one 1/2 inch (1. 25 cm) masonry drill bit. To minimize the risk of cracking the pot, it’s best if you use multiple drill bits when creating holes larger than 1/4 inch (6. 35 mm). Start with a 1/8 inch (3. 175 mm) drill bit and gradually work your way up in size until you reach the final desired hole diameter.
The tape can help prevent the drill bit from slipping as you work through the surface of the pot. It is not always necessary with soft, unglazed clay, but it can still help. Multiple layers of tape will work even better than a single layer. This provides even greater traction and may help ensure that the tape will stick on the pot, even in spite of the moisture.
If you only plan to use a single size, attach that drill bit to the drill now. [3] X Research source Use a cordless drill with variable speed for the greatest amount of control.
Essentially, the only pressure you apply should be to help keep the drill steady. Allow the drill to do the work of actually drilling through the pot. Working too quickly or with too much pressure could cause the pot to crack apart. If you are drilling through a surface that is thicker than 1/4 inch (6. 35 mm), you may want to pause and clean the debris away from the hole as you work. Doing so can help keep the drill bit cooler. [4] X Research source Peel the tape away after drilling your initial hole. You may even pause to peel the tape away as soon as you first break through the surface, but doing so is not strictly necessary. You shouldn’t have a problem with the drill overheating if the pot has been well saturated, but if the drill bit does begin to smoke, you will need to dip the pot back into water for a few minutes to cool down the surface. If you have a cordless, battery operated drill, you may even be able to touch the tip of the bit to water to help cool it, as well. Do not do this if you’re using an electric cord drill, though.
In this manner, you can slowly enlarge the hole while putting less strain on the clay. Work as you did before, applying light pressure and drilling slowly. Continue working through your various drill bit sizes in similar intervals until you reach the final desired size.
Inspect the pot to make sure that there are no deep cracks or chips. This step completes the process.
These drill bits have a spear point head, which allows then to cut into hard, brittle surfaces with less pressure. If you were to use a standard masonry drill bit, you would need to apply too much pressure to break through the hard glaze, and the pot would likely crack apart. The drill bit size should match the diameter of the desired hole. If you want to create a standard drainage hole in a medium sized pot, a 1/2 inch (1. 25 cm) drill bit should work well enough. It isn’t strictly necessary, but you might also want to consider using multiple sizes to further reduce the risk of causing breaks in the clay. Start with a 1/8 inch (3. 175 mm) drill bit and gradually work your way up through larger sizes until you reach the final desired size.
The use of tape is especially helpful with glazed clay surfaces, which tend to be somewhat slippery. This tape gives the surface just enough traction to help prevent the drill bit from slipping as you start drilling. One layer of tape should be enough in most cases, but multiple layers of tape will provide greater traction and are less likely to peel away during the process.
On the other hand, if you decide to use only one drill bit, simply attach that drill bit to your drill now. A cordless drill with variable speed is strongly recommended. This will offer you the most control while drilling, and the fact that the drill is cordless makes it safer to use around water than a corded drill.
If you’re drilling into a recessed bottom, you can pour a small amount of water over the indented portion of the pot and work with that. When you’re drilling into a flat surface, it helps to have a continual dribble of water pouring over it from a garden hose or faucet. The water acts as a lubricant, allowing the drill bit to work through the clay with greater ease and less pressure. It also acts as a cooling agent, which can prevent the drill from overheating. Clay pots with very thin glaze may not need any water, but applying water to the surface as you drill still won’t hurt.
The pressure you apply should be just enough to keep the drill steady. You should let the drill do the actual work of drilling through the pot instead of trying to force it through faster. This is especially important once you are nearly through to the other side of the pot, where the clay will be weaker. Working too quickly will probably cause the clay to break. When drilling through a clay surface thicker than 1/4 inch (6. 35 mm), consider pausing in the middle of the drilling process and brushing away any chips or other debris. This can help prevent the drill bit and drill from overheating. Once the drill bit breaks through the surface of the pot, you can pause your drilling and peel the tape away. If you don’t wish to pause, though, you should at least peel the tape away after you finish drilling this first small hole.
Center this drill bit over the center of the hole as you drill through it. This is a fairly safe way to slowly enlarge the hole. As before, drill slowly and apply little to no pressure. Work through the remainder of your drill bits in this manner, upgrading by about 1/8 inch (3. 175 mm) each time, until you reach the final desired size.
This step completes the process.
