1 Cups, 4 in. (10 cm) in height, wood-fired porcelaneous stoneware, thick shino slip, 2017.

Until about five years ago, Zac Spates’ work was purely functional. He came up as a potter under the likes of Mark Hewitt and Richard Bresnahan, two well-known wood-firing artists whose straightforward forms allow room for complex surfaces.

In 2013, something changed for Spates. He was living in Colorado helping to build a house with his wife’s uncle, spending much of his free time rock and mountain climbing. The surfaces he was surrounded by changed the trajectory of his work. “Just staring at all these rocks on the weekends, I wanted to introduce that look in my pots,” he says. “That’s where the faceting comes from, and anything that’s carved comes out of that. I want to continue to move my pots into looking like they’re pure rock.”

To capture this look, Spates first ripped the edges of facets to get the rough texture on the surfaces of vessels. Then, he started working with torn edges on larger, flatter pieces (like trays). Last year, Spates began carving solid blocks of clay to achieve the torn edges and surfaces that most closely resemble rocks. He carves the outside surface from the block, and then he carves the inside surface to match using a combination of trimming tools, a wire, wooden ribs, and a pottery knife. Since his clay is really non-plastic, it tears easily, which is integral to his work, rather than being a fault. Spates processes the clay himself to ensure it doesn’t get too plastic. One thing that has remained consistent throughout this development is wood firing, a method that hooked Spates from the very beginning of his clay career. The combination of faceted forms and complex, wood-fired surfaces creates earthy work that toes the line between sculpture and function—a boundary Spates plans to continue pushing.

2 Torn tray, 24 in. (61 cm) in length, wood-fired porcelaneous stoneware, various slips, 2017.


Spates took his first pottery class as a junior in high school, but at the time, he never imagined ceramics would turn into a career. In fact, he was a pre-med student at the University of Minnesota, Morris, for his first year of college. The intensity of his studies led him to sign up for a pottery class, attempting to break up his days of biology classes and provide some stress relief. During that class, he got in touch with a few studio potters in New London, Minnesota, who wood fired their work, and his passion for wood firing was ignited.

When he enrolled in Saint John’s University in Collegeville, Minnesota, in 2000, he declared a major in studio art. “I think the main reason I really got into it early on, and I hear this all the time from other people, is that it’s very therapeutic,” Spates says. “You can forget time. I know when I was in college, I would spend 12-hour days in the studio during the summer just making pots all day . . . I even forgot to go eat. It just kind of sucked me in.”

He took ceramics classes in school, but he also spent about 30 hours a week as a studio assistant for Richard Bresnahan. Instead of making pots during these hours, Spates learned about another potter’s process and practice. “He dug his own clay, and we would refine it and blend it and clean it up, and then I’d pug it all up for him. It was a pretty labor-intensive process,” says Spates. “This helped me to understand the process of refining clay straight from the ground. It was important to sieve roots, rocks, etc. out to get a more plastic clay for his thrown pieces. As a young potter, it opened my eyes to what we normally don’t see with processed clays.”

 3 Mug, 5 in. (13 cm) in height, wood-fired porcelaneous stoneware, thick shino slip, 2017.

After college, Spates apprenticed with Mark Hewitt in North Carolina for about 3½ years, which was hugely influential on the development of Spates’ own work. During his apprenticeship, he helped to make Hewitt’s ceramic work, which he describes as highly functional with roots in English pottery traditions. This approach continued in his own work after the apprenticeship. 

During his apprenticeship with Hewitt, Spates took a month-long trip to England to build a wood kiln with Svend Bayer. Spates says, “He and Mark [Hewitt] are really good friends, and they had both apprenticed with Michael Cardew, so it was kind of the same school of people. It was basically the same English-style pottery that led back to each other.” Reflecting on the experience, he explains, “Working with Bayer was a huge, life-changing experience for me . . . . it helped me to understand the process of building kilns. He was very thorough with his plans and builds, and being a part of it helped me to understand that cutting corners wasn’t an option in kiln design. I used this lesson in my own kilns, and the one that I built for Mark Hewitt at the end of my apprenticeship. I have always wanted my kilns to look as nice as the pots that come out of them.”

Spates’ apprenticeship with Hewitt wrapped up in 2006, at which point he began work as a full-time studio potter. He set up a studio in St. Paul, Minnesota, at Carleton Artist Lofts, where there was shared space in the basement for pottery. During this period, he traveled to help other artists with their wood firings, and in exchange was able to include some of his work in the firings.

4 Carved box, 7 in. (18 cm) in height, wood-fired porcelaneous stoneware, 2017. 5 Torn plate, 10 in. (25 cm) in length, wood-fired porcelaneous stoneware, local clay slip, 2017.

At first, his forms were reminiscent of Hewitt’s: they were very unambiguous, thrown, functional wares. Even as his art began its transition to more sculptural, nature-inspired, altered forms, his basic process of wood firing remained a constant. Spates left the surface a minimal, slipped canvas. He says, “I’m looking for the wood firing to give them those different surfaces. I fire my wood kiln for four or five days . . . . during that time I introduce charcoal into the kiln (see sidebar below in orange), and at the end of the firing I reduction cool the kiln with charcoal. That process creates surfaces that are different from a straightforward oxidation cooling or a regular firing. It mattes out the surface, it develops a different style of surface. On the shino slips I have, [reduction cooling] makes them a little more satiny. I want the forms to be fairly simple so that I can develop the surface of the pots based on the firing.”

Spates’ priorities are evident in his finished pieces. Hefty and intentional, the simple forms are blasted with warm color and rich texture from the wood firing.

The Appeal of Wood Firing

Spates’ entire ceramics career has been centered on wood firing. During college, he would make his pots in class and then fire them with a potter named Bill Gossman, who was Spates’ first wood firing teacher. “I was always drawn to wood firing,” he explains. Sitting in front of the kiln, adding wood, and controlling all the moving parts was far more engaging to Spates than other firing methods. Another draw is the inevitable surprise.

This surprise—a wood-fired surface’s ability to defy expectations—keeps Spates going. Chasing the varying colors of adding charcoal, he makes work for the sake of firing. The decisions he makes from start to finish on a piece are informed by and based on the different outcomes that are possible in a wood firing.

Around 2009, Spates and his wife moved to Hudson, Wisconsin, where he set up a small studio. He built two wood kilns, and two years ago he started work on building a new studio with a gallery space above it, which he’s just finishing up now.

6 The front of Spates’ anagama kiln.

Introducing Charcoal into a Wood Firing

When firing with Mark Hewitt, Richard Bresnahan, and in other kilns, I realized that under the side stoking areas, the pottery that was covered by the embers would always come out with interesting cooler temperature markings. The oranges, reds, yellows, etc. would come out with nice soft surfaces. To mimic this with small areas of the kilns, I started adding more charcoal in the side stoke areas. I did this after figuring out the right amount of reduction cooling for coloration on all of the pieces in the chamber. The pieces that aren’t immediately covered in charcoal generally change from a brown to a black or red depending on the clay’s iron content. The shinos also come out richer and with more variation. Speaking with other potters, including Eric Knoche, Josh Copus, and JD Jorgensen, helped me to refine my own process.

When reduction cooling with charcoal, I start with charcoal introduction around 2050°F, and with my smaller kiln (4×4×4 ft. stacking area), I will put a full (8 lb.) bag in the side port (for the big kiln I may put in 10 bags at once (80 lbs.)). I will put a second bag or half a bag (depending on the pieces in the kiln) around 1800°F (982°C), but before 1750°F (954°C) (usually about 1½ to 2 hours apart). I won’t put any more in after this point.

I sometimes add charcoal during the firings to aid the side stoke areas in developing some heat mass. When I do that, I put in some every 6 hours or so, which is how long they take to burn completely. I currently use Royal Oak 100% Natural Hardwood Lump Charcoal.

7 Faceted bottle, 12 in. (30 cm) in height, wood-fired porcelaneous stoneware, thick shino slip, 2017.

Passion for Passing the Torch

While Spates is a full-time studio potter, he also fills his time with teaching both pottery and, appropriately, firefighting.

“I teach pottery at White Bear Center for the Arts in the Twin Cities, and in addition to that I spend a lot of time as a captain on our local volunteer fire department,” he says. “I really got into it; I actually teach firefighting for our local technical college to beginning firefighters. I’ve been teaching for a couple years, and I’ve been with the fire department for about eight.” It makes sense that Spates would be interested in both wood firing and firefighting, but not just because of the obvious connection of fire; the two tasks are involved and intensely physical, and they give him the opportunity to be outdoors, a favorite hobby and inspiration to his work. There is a conceptual connection between the two, as he explains, “It’s all about the way fire moves and how you control it. I am so interested in understanding how fire behaves and reacts to its environment.”

Spates also loves teaching in general; he says it allows him to escape from his own little world and keeps his skills sharp. “One thing that I like is that it’s a little break from what I’m doing,” he says. “It’s a different thought process to help a student work through their problems. Basically, the class that I run is an intermediate to advanced class of students. They come in with their own ideas, and it’s always fun to work through those ideas with them. For me, it’s so different because I know what I want to do, and I know what my ideas are, but helping someone else work through their own ideas, is a different style of thinking. It keeps me on my toes.”

This summer or fall, Spates is moving his kilns and studio east of St. Cloud, Minnesota, so that he can work as an airfield firefighter, his wife can continue her job in St. Paul, and he can also continue work as a full-time potter. He is excited about what this will do to his work, and plans to experiment more with solid clay sculpture as a continuation of his interest in rock forms and earth layers.

Monthly Method: Carved Boxes

To create one of his carved boxes, Zac Spates begins by wedging an 8-pound ball of clay. He shapes the clay to a rounded cone (1). After shaping, he runs a metal rib against the surface, holding it perpendicular to the clay to tear it (2). He formulates his clay to be fairly short and non-plastic so it tears easily. Then, he makes slight cuts, in this case on the top and the side, with a fettling knife to further shape the clay. He does not cut all the way through, but instead tears off the partially cut piece of clay (3).


After finishing the surface treatment, Spates cuts the top and bottom of the box apart, using a pair of bricks to guide his cut-off wire through and create an even, straight cut (4).


Once the piece of clay has stiffened up and the outside is hard enough to preserve the texture he created when the form is handled, Spates hollows out the two pieces. He makes an initial carving to outline the top of the walls with a trimming tool (5). He then uses a circular loop trimming tool to continue the process of hollowing out the form, and eventually smooths the walls to blend in all of the trimming cuts (6).

Since this piece is not thrown and the clay is fairly short, Spates uses a wooden rib to compress the bottom, inside and out, to prevent cracking (7).


Next, Spates rolls out a slab that is about 38 inch thick and cuts a 34-inch strip to attach to the top piece to form the flange for the box. He uses the wooden rib to smooth out the transition between the outside edge and the flange, and his finger to smooth the inside of the clay strip to attach it firmly to the inside of the box (8).

Spates has now completed the form (9). Notice the slight difference of the surface and how the rough edges have been slightly compressed as he worked on shaping the interior. He usually tries not to touch the outside of the piece after he textures it, but as he hollows out the inside of the piece while resting it on foam pads, the texture slightly softens in the process.


To see more of Zac Spates' pots online, visit http://zacspatespottery.com, Schaller Gallery ( www.schallergallery.com), and Northern Clay Center (www.northernclaycenter.org ). 

the author Jessica Cabe studied arts journalism at Syracuse University in New York and has been a clay hobbyist for four years. She lives in Chicago, Illinois, where she works as a freelance writer.