Slab-built plates seem like a pretty simple endeavor, but it can be challenging to center the feet just right. Coil feet often have that pesky bump where the coil is joined and if you throw a foot on a slab plate or bowl, you can often have problems with cracking.
In today’s post, an excerpt from Handbuilding Techniques, Liz Zlot Summerfield shares her nifty technique for getting a slab foot just right. – Jennifer Poellot Harnetty, editor.
Handbuilt slab plates are a lovely addition to any potter’s repertoire. They are versatile in use, and offer an open canvas to play with a variety of surface treatments. Although they only consist of two components, a slab and a foot, they are often loaded with pesky little problems. Here’s a technique that is sure to provide you with a proud product.
The weakest link in a slab plate is the foot. It’s often uneven, off center, and unconvincing. A common technique is to add a coil, place the plate on a potter’s wheel and throw it onto the slab. This often leaves a bump where the coils are joined and it has a tendency to crack. The fix to these issues is to create a foot ring and apply it as one cohesive piece.
Constructing the Plate and the Foot
Starting out, consider keeping the plate shape simple: try a square, circle, or rectangle. I like to handbuild this part of the plate but it can easily be thrown and altered to whatever shape you prefer.
Draw and cut out the shape of your plate on paper and make two copies of this shape. Save one to cut out the plate shape, and on the other draw a foot ring—this may take some experimenting as the size of the foot ring will alter the look and stance of the plate. Cut out the foot ring by folding the paper in half, then cutting along your drawn lines. Once the paper foot is cut out, you’ll be left with a stencil to help center the foot ring on the slab.
Roll out a slab large enough to trace around one plate template and one foot ring template. For smaller plates, I roll to a thickness of about 3⁄8–½ inch. This thickness alleviates warping during the drying and firing processes. After rolling your slabs, it’s important to run a rubber rib along the surface of both sides of the slab. This compresses the clay particles and removes any canvas texture from the working surface. Throughout the rest of the process, work on untextured surfaces such as drywall boards or a smooth fabric.Trace the patterns with a needle tool before cutting them out with a knife. Hold the knife perpendicular to the slab and cut in one even motion (figure 1).
Applying the Foot
Place the stencil onto the cut out slab and trace the interior ring with your needle tool. This traced line will act as a guide as to where to place the foot ring and keep it centered (see figure 1). Since both the clay slab and foot ring are the same consistency and very wet, you will only need water to attach the foot ring to the slab. Brush water onto the slab and put the foot ring in place using the traced lines for guidance. Gently apply pressure with your thumb and index finger to affix the foot ring to the slab. Refine the finished foot ring to follow your aesthetic. Avoid using any additional water as you refine it and smooth just with your fingers. A rubber-tipped tool is useful in cleaning and blending the connection between the slab and the foot ring. The final step in applying the foot ring is to use a small roller to eliminate unevenness (figure 2). Leave the plate upside down until it’s ready to be flipped and formed.
Shaping the Plate
Success in handbuilding functional forms is about knowing the correct timing to touch the clay. When the plate reaches soft leather hard, flip it over onto its foot and place it onto a small board. Next, place the board on a banding wheel. Place your fingers under the plate and your thumbs on top of the plate and gently press down in the center (figure 3)—you’ll feel the foot ring under your thumbs. Press against the foot ring to create more depth in the plate. Use your fingers to gently lift the sides of the plate. Slowly work your way around the plate by spinning the banding wheel. Finally, look at the edges of the plate from eye level and make sure there is an even curve on all four sides. Gently cover the plate with plastic until it becomes stiff leather hard and appropriate for surface decoration.