The audio file for this article was produced by the Ceramic Arts Network staff and not read by the author.
My first introduction to working with clay was in a community college course, and, if I’m being honest, I wasn’t immediately inspired. I know I probably shouldn’t begin with a less-than-jazzed origin story, but it seemed like everything I made was heavy, wonky, ambiguous, and, more often than not, cracked. I was beginning to learn that clay has the amazing ability to humble artists at every level.
After several failures, I told myself I would ride out the rest of the course and never again sign up for ceramics. But, by the end of the semester, I changed my mind. My professor, Tate Rich, created a welcoming atmosphere and built a community of enthusiasts who learned from one another.
When Tate introduced me to the salt/soda kiln, it was game over (or should I say, “Game on!”?). There was something magical about this beaten-down kiln. There was a hole in the chimney, the floor was 3 inches (7.6 cm) of glass, all the shelves had a chip (or three), and it took about a day to reach temperature. Even though 80–90% of the work I pulled from this kiln was still wonky, heavy, and cracked, my new love for the process couldn’t be swayed. I switched my major to ceramics the next day and haven’t stopped firing salt/soda pieces since.
I am drawn to soda firing for many reasons, one being that it produces nuanced variations in color and texture in a fairly short amount of time. Another reason is that the flame and soda leave behind the visual evidence of flow, often reminiscent of soft waves rippling over rocks on a riverbed floor. These gentle curves are a recurring motif in my work, echoed in my shapes and forms. When I’m in the studio, I think about how the form I am making will compliment the firing, influence the stack, and the work that surrounds it.
It’s amazing what difference a clay body can make in a soda firing. I didn’t quite understand how big of an impact the clay made until I read Gail Nichols’ Soda, Clay, and Fire. Reading this book made me explore a plethora of clay bodies and found that some of the most useful information in Nichols’ book is the importance of the silica-to-alumina ratio in a clay body. After experimenting with many different clay recipes and ratios, I have landed on the ratio of 2.9 silica:1 alumina, found in my Tile 6 clay body. This ratio allows me to pull a variety of colors while retaining a raw, natural feel that is not totally engulfed in soda.
Flashing slips are crucial in my making process; slip not only adds a fine-particulate surface on the form, but also allows me to showcase a bit of my hometown in every piece I make. The slip I use is based off of Randy Johnston’s Newman flashing slip recipe, modified with clay I dug and processed in Douglas, Arizona. This additive is a high-iron, low-fire clay I found while driving on Get Lost Road with my father, and is a way to keep that memory alive for me. I mix my slip to the consistency of skim milk and apply it to bisque-fired work, usually as a very quick double dip or by pouring the slip on (see 10). For forms that are harder to achieve a clean glaze line (like a pitcher), I will bisque the slip on, which allows for an easy glaze cleanup.
I start the process by weighing out 7–8 pounds (3.2–3.6 kg) of firm clay and throwing a tall and narrow cylinder. This cylinder will have no floor with an opening of around 2 inches (5 cm) wide, leaving the base walls slightly thicker to support the rest of the alteration process. I create a very slight curve that starts from the base to the two-thirds mark up the cylinder. I will then start a slight curve inwards at the last third of the form, keeping in mind the 1½–2 inch (3.8–5 cm) spout that will be added later. This is a very simple form that is exaggerated after the flattening process, and I start all the alterations directly after throwing the form.
Creating a Spout
When making spouts for my pitcher and katakuchi forms, I start by rolling a coil. For a pitcher, that coil is around ¾ inch (2.16 cm) in diameter. Then I cut the coil into 1½–2 inch (3.8–5 cm) logs (1) that I make into little crescent shapes and pinch out the general form of the spout (2). Once I have the spout pinched, I will then score it to the cylinder and start gently pulling and elongating the spout using the tips of my thumb and index finger (3). After I finish pulling the spout, I create a so-called chin. I believe the chin on my pitcher form brings a feeling of pride and makes it stand ever so slightly taller. I bring out the chin by supporting the sides of the spout with one hand and gently running my index finger along the spout with gentle downward force to curve it outward. It is important to leave a sharp, but not brittle edge when pulling a spout, this will allow for a clean stream that does not dribble at the end of the pour.
Darting and Altering the Form
Now that the form is starting to resemble a pitcher, I will mark a line down the middle of the pot and start the darting process. I learned about this way of altering during a Stuart Gair workshop. Stuart is one hell of a maker and a solid shot at basketball. After marking a middle line, I make two more marks, 1 inch (2.54 cm) below the rim and another about ½ inch (1.27 cm) below my fist size. This acts as a great guide before actually cutting into the cylinder. While there are many different shapes that can be used to dart a form, I cut out a raindrop shape that is slightly taller and wider than the size of my fist (4) and close off the hole that was just cut out by scoring and slipping, then joining the cut edges (5). Darting leans the spout back slightly and adds a perfect home for a handle.
After the spout and dart have been added, I cut the pitcher off of the wheelhead and start the flattening process. Instead of paddling the walls to reach the desired shape. I start by making a V-shape with my hands and cupping the walls of the pitcher, coaxing the form by gently squeezing down the length of the spout and dart (6). Add a slab bottom after shaping and refine (7).
Leaving a Mark
When I was studying in Japan, my sensei, Yuuki Matsuba, would give a demonstration in every class. While I learned a great deal about his throwing/trimming techniques, I always found myself admiring the way he showed great reverence in his mark making. Matsuba would leave behind beautiful marks that showed the process. I will never forget the time he demonstrated the making of a jar. Matsuba took a 10-pound (4.5-kg) ball of clay, placed it on the center of the bat, punched the floor of the jar out, and effortlessly threw a beautiful jar that showcased the process. I leave subtle marks of process when making a pitcher, like adding a slab base without blending or leaving score marks adds a small touch to be found upon closer inspection.
Handles are a difficult process for me, and learning how to pull a nice handle takes years and years of practice. Something so small and seemingly simple is often overlooked and rushed. While they aren’t my strong suit, I always aim to add a comfortable handle that has enough visual weight to carry the form (8, 9). If necessary, I will beef up the handle by adding coils around the attachment points.
Loading and Firing
Loading the kiln for flashing is a strategy game, which I like to think of while making work to be fired. When loading the kiln, it is crucial to keep in mind the flow of the flame and how to use that to your advantage with mark making. Loading atmospheric kilns for flashing, in conjunction with clay bodies and slips, is about blocking out the flame path with wadding, work, saggars, bricks—anything that goes in the kiln can be used for this. I stack the kiln load fairly tight and always have a form almost touching another (see 11).
Soda firing can be full of surprises, there are so many variables that can drastically change the final product. Firing is my favorite part of making, along with finishing work, it’s what made me switch my major to fine arts. After loading and letting the kiln candle overnight, I start firing the kiln around 3am the next day. After slowly coaxing the kiln past quartz inversion, I open the air valves on the Venturi burners, pull the damper to where it is almost fully open, and start bumping the gas. Controlling damper, air, and gas differs with any kiln, however, my main goal is to have the kiln in complete oxidation up until I start downfiring, skipping body reduction. I make no changes to the kiln other than pulling or pushing the damper slightly to achieve an even temperature from top to bottom. I spray 3–4 pounds of sodium carbonate dissolved in boiling water. The exact amount is dependent on how tight the kiln load is—a tighter load will need more. I start the soda introduction process when cone 8 is halfway down, spraying for around 35 seconds each time in oxidation (this helps achieve a white soda buildup) and note how much the kiln drops. I spray until the temperature builds to 5 degrees over peak. After cone 10 falls and all my soda solution has been sprayed, I bring the kiln down to 2000°F (1093°C) over the course of 1½ hours and start down firing in reduction. I lower the gas considerably, close the air valves, and push the dampers in to about 1–1½ inches (2.54–3.81 cm) open. My goal is to reach 1650°F (899°C) in the course of 4–4 ½ hours. When the kiln stalls, I lower the gas slightly and push the damper in around a 16th of an inch. Once the kiln reaches 1650°F (899°C), I open all the ports and damper, adding air to oxidize the firing for 5 minutes to bring out reds from iron in the slips and clay.
I am always on the lookout for a vibrant range of colors and dramatic flashing. I always aim to include at least one test piece in the kiln, and those are the most surprising. Of course, an atmospheric firing will not be a true firing if there weren’t any casualties or sacrifices—it’s part of the firing process and keeps any firer humble.
In addition to the many people who have helped me out in so many ways, from my countless questions to helping me get a firing through, I also want to thank Northern Arizona University, Jason Hess, and Steve Schaeffer for continually pushing me to explore and for giving me the life-changing opportunity to study in Japan.
the author Johnny Arvizu grew up in a small border town called Douglas, Arizona. He is currently a post-baccalaureate student at Northern Arizona University, and plans to attend a master’s program shortly after. Learn more on Instagram @Johnny.Arvizu.