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Published Jan 11, 2021

There is an abundance of clay in my area, and I have occasionally thought about making work out of local clay, but learning how to process clay from the ground seemed intimidating (or maybe it was just pure laziness!), so I never actually tried it. But learning how to process clay from the ground is not all that difficult. It might not be practical for everyone, but if you're willing to do a little bit of manual labor, digging clay by hand can be a great way to create an even closer connection to the work you make, and help lessen your carbon footprint in the process.

In today's post, an excerpt from Handbuilt: A Potter's Guide, Melissa Weiss shares pointers on digging clay by hand. Plus we share a video (an oldie, but a goodie!) by Graham Sheehan that walks through how to process clay for use in the pottery studio! - Jennifer Poellot Harnetty, editor

Tips on Finding and Digging Clay for Pottery

I bought land in the Arkansas Ozarks with friends in 2002 before I was a potter. Little did I know it would become my clay farm. I had no idea what I was doing the first time I dug up a bucket of clay on the land and brought it back to my studio in North Carolina, but I tested it by making a pinch pot. I didn’t know what would happen to it in the kiln, so I placed it inside a bowl made of trusted clay and fired it that way. If the pinch pot melted, I would only have sacrificed one bowl. I got LUCKY! The pinch pot survived the cone 10 firing.

Next, I made a wild clay pinch pot to test each glaze I used. When these came out of the firing, the glazes had shriveled and cracked off the pots. This meant my clay was shrinking far more than the glazes. The clay was also hard to use because of its naturally sticky and crumbly qualities. It was too short, not plastic enough. When I rolled a coil and bent it, it broke in half. This is a common issue with wild clay.

Testing Locally Dug Clay

Now I needed to turn my wild clay into a workable clay body. I had no idea what that entailed, and that’s probably what kept me from overthinking and becoming overwhelmed at what to add and how much. I asked friends who’d tried the process where to start and, with their advice, I came up with a basic recipe and tested it. Then I spent the next few months tweaking the recipe, testing ingredients in differing amounts. When the clay body finally came out the way I wanted it—durable, vitrified at cone 10, rich and beautiful in color, interesting, and workable—I was done. I loved it.

I could never go back to sterile, clean-bag clay. The recipe utilized my wild clay at 25 percent, which seemed a realistic amount to dig and haul all that way. My partner and I make the long drive to Arkansas once a year, get out our shovels, and dig an actual ton—2,000 pounds—of clay, packing it into 5 gallon plastic buckets. We load this into our van to take back to North Carolina. The clay remains in the buckets and dries out. When we’re ready to make a batch of clay, we chip off hunks of it, weigh out the proper amount, and incorporate it into our recipe. Since we use the wild clay at 25 percent, it enables us to make 8,000 pounds of clay a year.

How to Process Clay from the Ground

We make 1,000 pounds of clay at a time—processing it is a labor-intensive task. We modified a 50-gallon food-grade metal drum to work in by cutting a hole in the bottom and fitting it with PVC pipe with a valve. This is what the wild clay goes into. We add water and use a power drill with a paddle attachment to mix it until it is liquid. Then we open the valve and screen the clay through wire mesh into a 300-gallon metal trough. We’re ready to add the other ingredients into the screened wild clay slurry, mixing it with enough water until it is the consistency of heavy cream and all the ingredients are fully incorporated.

At this point, the clay must be drained of the excess water. We set up 2'x4' (61x122 cm) racks that we make with 2'x4' boards and ó" (1.25 cm) hardware cloth. Each rack has two 2'x2' (61x61 cm) compartments that we line with old sheets. Then we bucket the liquid clay into the compartments. When each is full, we stack another rack on top and repeat. And when all the racks are done, we have to wait.

Over a period of weeks (about two weeks in warm, dry weather, longer if it freezes), the water slowly drips through the sheets and wire mesh until the clay, while still soft, is dry enough to remove from the racks. Then we use a pugmill to further mix and incorporate any unevenness in the clay. Now it’s ready!

I’m often asked, “Isn’t there clay in North Carolina?” Of course there is. There’s lots of clay in North Carolina. It’s the main reason there’s such a rich pottery tradition here. There’s even a small clay-making company called STARworks Clay in Star, North Carolina, that makes many beautiful clay bodies from local clays.

Why dig your own clay?

Then why go all the way to Arkansas just to dig clay? I love my clay. I love its beautiful iron-rich color and its durability and strength. I’m attached to it in a sentimental way too, because it gives me a reason to visit my piece of land every year, to connect with that part of the world and my friends there. If it weren’t for my clay recipe, I doubt that I’d always find the time to visit Arkansas every year. So, I am grateful for this process that anchors me to my land.

Everything else in my life has changed since buying the land in 2002, but the clay is the same. I think about that a lot. My clay is a solid, dependable material conveying strength and consistency through all the calm and fury of a human life. Excerpted from Handbuilt: A Potter's Guide by Melissa Weiss. Reprinted with permission of Rockport Publishers, an imprint of The Quarto Group.

More Tips for Digging Clay

Check out the video below in which Graham Sheehan demonstrates how to process clay from start to finish!

**First published in 2010, updated in 2020 with new content.
Topics: Pottery Clay