In the Potter's Kitchen: Combining Clay and Cuisine Liz Pechacek

Appears in the Sept/Oct 2018 issue of Pottery Making Illustrated.

I love to combine handbuilding and slip casting because the finished work is often much lighter in weight and easier to replicate, yet retains the touched pinchy appearance of being entirely handbuilt. Layered with slip, stains, and glaze, the work achieves a rich and complex surface that above all communicates a sense of touch. I draw from a diverse range of historical sources for my work, such as Mimbres and Neolithic Chinese pottery and bridge these influences with Danish Modern ceramics and the work of such pioneers as Lucie Rie and Ruth Duckworth.

Casting the Large Serving Bowl

I use a brown stoneware slip with some plasticity, which makes it easier to manipulate after the casting. Test your slip by drying out a tiny bit on some plaster, then rolling it into a coil. If it just crumbles, it won’t work, but if it’s fairly pliable you can probably add a coil to it. Fill the plaster mold with casting slip, allow the slip to thicken, then dump the excess slip out of the mold once the wall of the cast is between ³⁄₁₆ and ¼ inch thick (1). Make sure it’s not too thin or it won’t support itself when you’re adding the rim.

When the clay form releases from the plaster, trim the edge of the rim to a beveled chisel point. The rim must be a wedge-shaped (or an upside-down v) point to properly splice into the added coil—it also makes it easier to pinch the two together. I use a Surform rasp to do this (2), then touch the entire rim with a damp sponge before wrapping the rim with a strip of plastic (3). Run your hands along the edge over the plastic and seal the water in so that the rim stays moist and pliable while the bottom of the piece firms up to leather hard. You want the bottom to be pretty firm and the rim nice and wet, so when you add the coil, the rim accepts the new piece of clay, but the shape doesn’t deform too much when you’re pinching them together.

Occasionally check the rim; with the plastic still on and dry hands, pinch all around the rim of the piece, making sure that it’s soft and pliable under the plastic. If it’s a bit dry, take the plastic off, add more water, and seal the plastic again to rehydrate the rim.

Attaching a Coil to the Rim

Roll a long slender coil of a contrasting colored clay body—be sure to use a body that has similar shrinkage to the casting slip. I'm using a pink colored clay body for the coil. You can also wedge color into the clay you're using for the base if it’s a light-colored clay body to get a different looking clay with similar shrinkage.

Remove the plastic from your rim and lay the coil all the way around it, keeping it as balanced on the edge of the shaped tip of the rim as possible (4). Work the ends of the coil together so you have a smooth donut perched on top of the rim and run your hands around the coil with your thumb and fingers, pinching the base clay underneath to center it a little more.

Now it’s time to combine the two together. Support the outside edge of the bowl while smoothing the coil down the inside (5), being as consistent as possible. The base clay will want to balloon out as you do this, but keep support on the outside to prevent too much distortion as you make your way around the entire circumference.

After the inside edge of the coil has been completely worked into the bowl, take both hands and curl them around the coil with the fingertips and thumbs pinching right underneath the coil to accentuate the ledge of porcelain on the outside. This will facilitate the smoothing down of the coil on the outside. Pinch the thumbs toward the fingertips and squeeze your hands together slightly so that the edge of the base clay under the coil is pressed inward slightly, creating a ledge underneath the coil (6). Once you’ve done this all the way around, start moving the coil down the outside of the piece using the thumb on the outside and fingertips supporting on the inside (7).

After the coil is attached and blended, pinch the place where the added coil overlaps the base clay all around the circumference until the thickness is similar to the base clay underneath. Then pinch the added coil upward (8) with two hands side by side and a slight pressure of the hands toward each other. If you don’t squeeze the clay together and up between your two hands as you apply pressure between the thumb and fingertips, the clay will expand outward, but not upward.

When you are satisfied with the thickness and height of the added coil, spin the piece at a mild pace on your banding wheel to smooth and tune the shape with a stiff rib (9). You’re done forming the piece. Set it aside to dry and get yourself a treat.

Fine Tuning the Bowl

Once the piece is bone dry, put on a properly fitted respirator and sand the top rim of the piece with a dry kitchen scrubby pad to knock down the highest bumps—I use a medium-coarse pad. Always wear the respirator and work in a well-ventilated area while creating any clay dust. After you like the way the rim looks, sand the outside of the added coil. Pay close attention to the spot where the bowl and the coil come together to remove any smudges of one clay onto the other (10).

Inlaying a Slip or Underglaze.

You could stop at this point to really highlight the two-clay technique, but I love the way different layers of texture and color combine to form the final effect of the serving bowl.

Lightly wipe down the whole piece with a hand towel, then invert it onto a bat. Water down some wax resist (⅓ wax to ⅔ water), and use a fan brush to apply an even coat to the entire exterior. Allow the wax to dry. With a sharp needle tool, scratch radiating lines from the foot to the base of the added coil (11). Wearing a dust mask again, brush the lines out as you progress around the piece. After the lines are completed, give the whole exterior a light brushing to remove most of the surface dust. Don’t forget to add a design or pattern to the bottom of the bowl.

Next, decide what color slip or underglaze you want to inlaid lines to be. Using a fan or large calligraphy brush, paint the slip or underglaze (watered down to the consistency of watercolor paints) all over the carved wax area and allow it to dry (12). Use a mostly-squeezed out sponge to lightly wipe any residue of the slip or underglaze off the waxed surface (13). Apply wax again to the bottom and scratch in your signature if you wish, then paint in another color before drying and bisque firing (14).

Finishing Touches

After the bisque firing, lightly buff any remaining residue of the inlaid color off the surface using a scrubby while wearing a mask and working in a well ventilated area. Carefully wipe down the piece and glaze the interior. Allow the piece to completely dry.

Now, decide where you want the added decoration of glaze stripes to appear on the outside of your piece. Mark the perimeter of the glaze area with a pencil, then wax just underneath the pencil line with a steady hand on a banding wheel.

To create the bands of glaze, use a squeeze bottle with a long narrow tip and a cap with a wire to keep the shaft clean and fill it with undiluted, water-based wax. Steadily trail stripes of wax, being careful not to blob or smear the lines (15). If a mistake occurs, scrape it off with an X-Acto knife. Allow the wax to dry for a few hours, then brush a diluted glaze of your choice over the wax-striped area with a fan or calligraphy brush (16). Wipe the rim and the edge of the glaze stripe area with a sponge and fire to glaze temperature.

Liz Pechacek earned a BFA in ceramics and a BA in art history from Indiana University in 2012. She now operates her ceramic studio in Minneapolis and teaches at Powderhorn Park. To see more, visit www.lizpechacek.com.