The Process Behind Wheel Thrown Ceramics
Are you curious about how wheel thrown ceramics are created? Well you've come to the right place! In this post I will cover all of the different steps involved in wheel thrown pottery from start to finished piece!
Step One: Prepping Your Clay
The first step involved in creating wheel thrown pottery is preparing your clay. While not totally necessary, it is beneficial to wedge your clay well before use. This helps awaken the clay as well as remove any air pockets that may be trapped inside.When using fresh clay, it is unlikely you will find air pockets, but it is much more common when working with your reclaimed clay. This is also a great opportunity for you to add inclusions to your clay such as mason stains if you want your clay to have a neat marbled appearance, or to just change your clay colour to something more exciting!Step Two: Throwing on the Wheel
Once your clay is prepped, you can take it to the wheel to throw your forms! This is the step that requires the most skill and patience, especially when you're learning. The wheel can be tough, but once it is mastered, you can create pots both beautifully and efficiently. The steps involved in throwing include centring your clay, opening your clay, pulling your walls, shaping your pot, and trimming your base. You can then place your pots in a damp closet or box over night before moving on to the next step in the creation process.
Step 3: Trimming Your Pots
After your wheel thrown pots have had some time to firm up, you can take them back to the wheel for the trimming process. Trimming your pottery involves turning your pot upside down on the wheel head and using specialty tools to remove excess clay from the base and walls. This is an important step to reduce thickness and make your pots lighter and more comfortable to hold. My students often ask how thin they need to make their pots, or when they should know when to stop. I like to tell them that it depends on the pot you are making. If you are making a vase, maybe it's ok for it to be a bit more bottom heavy so that when flowers are placed in them, they have less risk of tipping from heavy blooms. If you are making a mug, it's more important for it to be light, so you don't have to get an arm work out when trying to drink your morning coffee. You will be filling that mug with liquid, so if it is already heavy on its own, think about how uncomfortable it will be to use once full. This is also a good opportunity to add any decorative carving that you want to be symmetrical. You can use tools to carve bands all around the outside of your pottery, or do some more organic wavy textures. The possibilities are vast!
Step 4: Attaching and Decorating
After trimming you can start to attach handles or other appendages to your pottery. Pots at this stage are called greenware and should be at a leather hard consistency for good attachments. Pots that get too dry will be very difficult to attach things to and will often have serious cracking and adhesion issues. Use this brief window to do all of your attaching and sculpting as well as carving. After you have made an attachment to a pot, it needs to go back in the damp closet or box for at least 24 hours, but I often like to do 48 hours to be safe. Extra thick or wet pottery can even be left wrapped for multiple weeks to really slow down the drying process. Attachments that aren't wrapped will often dry too fast and crack and fall off, so it is important to slow dry pots after making attachments.
Step 5: Underglaze and Drying
After I have left my pots to dry slowly over a day or two, I like to add any underglaze painting that I wish. You can see examples of this in my mugs and vases where I have created illustrations on my pottery. I prefer to apply my underglaze at greenware stage so that I can easily correct any mistakes and carve into my illustrations. I also like that the bisque firing solidifies my underglaze paintings so they are less likely to bleed or blur with clear glaze applications. It also means I can apply wax over them so that no gaze sticks to the image, and I can sponge them down without smearing my designs. Once my painting is complete, I can then leave them on an open air shelf to fully dry. We call this stage bone dry. It is important for your pottery to become bone dry before going in the kiln to reduce the risk or cracks, warping or even explosions. Speaking of explosions, I like to take this opportunity to teach my students about the myth of air bubbles in clay. Many will tell you that if your pottery has air bubbles, it will explode in the kiln. This isn't an accurate statement and I will explain why. When air is heated, it tends to expand, but it does so at a fraction of the rate that moisture does. If a piece is bone dry but has an air bubble, it is very unlikely it will explode in the kiln because the expansion rate of air is so minor. If a piece is damp and has an air bubble, its chances of exploding are much higher because this pocket of air becomes the perfect container for moisture, which expands at a much greater rate. That being said, a pot that is damp and has no air bubbles has just as high of a chance at exploding as one with air bubbles. Don't be afraid of small pockets of air, be afraid of moisture in your clay. Moisture is the real killer of pots.
Step 6: Bisque Firing
Once the pots are sufficiently bone dry, they can be placed in the kiln for the bisque fire. The bisque fire hardens the clay, but leaves it porous enough to accept glaze applications. A bisque fire typically takes 8-12 hours to complete. Even though your pots feel sturdy once out of the bisque firing, caution should be taken when handling your work by handles or other attachments. They are still easily chipped or broken at this stage. Pots that have come out of a bisque fire are no longer called greenware, they are now called bisque ware.Step 7: Applying Glaze
Now is the time to apply glaze to your pottery. It is beneficial to wipe down all of your bisque ware with a damp sponge before applying glaze to remove any dust or fine particles from the surface that may cause pinholes. There are many different techniques for applying glaze including dipping, brushing, sponging, or airbrushing. There are so many rules that go along with each technique that it will require a separate blog post just to go over the nuance of glazes, but know that this is the next step after the bisque fire. One thing to note, it is very important that you are using the correct glaze for the type of clay and firing range you are doing. There are low fire clays that use low fire glazes, as well as mid and high fire clays and glazes. Make sure that if you are just starting out on your glaze journey, that you do some research to make sure you are purchasing the correct materials for the job. Don't risk damage to the kiln by neglecting your due diligence.
Step 8: Glaze Fire
After your glaze is applied, you can load your pots back in the kiln for their second firing. This is called the glaze fire and it typically takes 8-16 hours. It can take just as much time for the kiln to cool enough to be opened once firing is complete, so it often feels more like a 16-32 hour firing. Opening a glaze kiln is like Christmas every time. You can never be sure of how your glazes will turn out, and it's very hard to replicate the exact same results twice. It can be incredibly rewarding to see your finished pots, but it can also be very disappointing when things don't go to plan. But that is what makes the whole process so exciting!Optional Step 9: Applying Lustres
After your pots have come out of the glaze fire, you can apply different lustres to your work! These lustres include yellow gold, white gold, platinum and mother of pearl. These special lustres add a touch of elegance and iridescence to your work. These over glazes should be applied in a well ventilated area and a respirator should be worn during application. They produce fumes that are damaging to your health and can also make you feel dizzy or induce headaches if inhaled. Use caution during application and try to refrain from getting the lustres on your skin to avoid irritation. Lustres can be removed with acetone or turpentine but not water.''
Optional Step 10: Lustre Firing
After applying lustre, your pots go back in the kiln for a third firing. This is a very cool firing that doesn't get hot enough to reactivate your original glazes. It takes around 3 hours to complete this firing. When your pots come out of the kiln, you will see the magnificent results of your lustres. Pots fired with lustre should be hand washed and should not go in the microwave.