For a couple of years now, I have been trying to make the switch from wheel throwing to handbuilding so I am always on the hunt for slab pottery ideas. Recently, I have been looking obsessively for ceramic platter ideas. I know how to make a platter on the pottery wheel, but with limited time in the studio, I really need to come up with a ceramic slab project that I can repeat again and again.
today’s post, we put together a time-lapsed excerpt from Birdie Boone’s video Simple Elegance: Slab Building & Glaze Color Exploration. In it, Birdie Boone shares a plate-making technique in which she uses a simple oval template (but you could use any shape really) to make an elegant piece of slab pottery. – Jennifer Poellot Harnetty, editor.
PS. To see the full project in real time, pick up a copy of Simple Elegance: Slab Building & Glaze Color Exploration in the CAN shop (30% off for a limited time!) or subscribe to CLAYflicks to see all the videos in the Ceramic Arts Network.
This clip was excerpted from Simple Elegance: Slab Building & Glaze Color Exploration, which is available in the Ceramic Arts Network Shop!
To learn more about Birdie Boone or to see more images of her work, please visit www.birdiebooneceramics.com.
Plus, Step-by-step Instructions for Building with Templates
You needn’t make your template to my exact specifications, but these are the dimensions I’m working with (1, 2).
Plate Face (includes outer plate ring and center circle):
A 12 in. long axis
B 8¾ in. short axis
C 5¾ in. center long axis
D 3⁵⁄₈ in. center short axis
E 8³⁄₈ in. long axis
F 6¹⁄₈ in. short axis
G 4½ in. center long axis
H 3¼ in. center short axis
Cut the Plate Face
Roll out a ¼-inch-thick slab. I have a large drywall table top I use to pull moisture from the clay slab slowly and evenly. Using a needle tool, cut out the plate face, using your paper template as a guide. Remove the outer clay scraps, but leave the plate face and center circle intact on the board. Let it firm up to pre-leather hard before moving it to prevent distortion (3).
Roll out another small ¼-inch-thick (or slightly thinner) slab for the girdle and place it on a separate smaller drywall board. Leave it intact, and let it firm up to pre-leather hard.
Using the flat end of a pony roller, slightly thin out and widen the ring to ¼ wider all around. Bevel the new outer edge all the way around. This increase in size will accommodate the bevel on the seam edge of the plate face when the center is reattached. Set this piece aside for later use.
Cut a seam through one or both sides of the ring. Note: This is an aesthetic step, to bring visual interest to the plate. Consider that this seam could be on the long or short axis or two cuts could mirror each other. Bevel the edges of the cut (4). Brush the seam edges with magic water, then join and compress the ends together with a pony roller (5). This too is an aesthetic step: I prefer to leave the little tips, which result from the pressure of the pony roller, sticking out on the seam ends (see 8). These extra details provide visual interest around the pot.
Using the pony roller’s curved end, bevel the inner edge of the ring. Score and slip this edge really well. Add a bit of slip to the beveled edge of the center piece (set aside earlier), then invert it and place it back into the center. Tip: Don’t be shy when slipping and scoring. The clay is nearing leather hard at this stage, so you want to make sure you have a strong join. Using the palm of your hand, gently tack down the center piece. Use the pony roller to compress the seam (6). Flip the plate face over (upright) to inspect the seams (7). If the seam looks tenuous, lay it face down and use your finger to compress right up along the edge near the seam. You want to make sure the seam is secure, but still visible, since the purpose of the two plate face pieces is to create visual interest. If it’s not secure enough, it may separate during firing.
At this point, let the plate face set up to leather hard. You want it soft enough to work with, but firm enough so that once all the steps on the hump mold are finished, the plate is firm enough to be removed from the mold and hold its shape without slumping.
Assemble the Plate
Place your hump mold on a banding wheel. Tip: To avoid a very flat or uneven floppy plate, use a mold that has a considerable curve. This type of plate will flatten out a bit at several stages in the process and a more acute curve helps to counter balance this. Place the plate onto the mold face down. Once centered, gently pat the form to fit the plate to the mold. Use a firm but flexible rubber rib to compress the outer ring of the plate, making several passes (8). It’s very important to compress, compress, compress to help alleviate warping and cracking.
Using a Surform, remove the excess clay at the seam between the plate face and the center piece (9). The variations from thin to thick cause drying stress, which in turn can lead to cracking.
Adding the Girdle
Center the girdle piece on the plate face (still facing down on the mold) and mark the outline with the tip of your needle tool. Remove the girdle, lay it flat, score it with a serrated metal rib, then add slip. Slip and score in the outlined area on the plate face (10). Tack down the girdle, then use firmer pressure with a rib to seal the connection (11). Tip: Listen for squishy noises when you compress, it signifies a good join. If the girdle slides around, there may be too much slip. If so, let it sit for a few minutes so the two pieces can absorb the excess water, then compress the parts again.
Adding the Foot
Using the small end of the pony roller, bevel the inner edge of the girdle piece on the long sides only (see 12). Notice that because the plate is oval, parts of the foot won’t sit flat. To elevate the short sides, score and add two small lugs of clay (12). Shape the coils so that the transition area is more or less level.
For the foot, you’ll need a ½-inch diameter coil. It should be firm but malleable. Size the coil for the foot by laying it on the inner beveled edge of the girdle. Cut it to the appropriate length, remove it, and join the two ends together. Slip and score the beveled edge of the girdle. Tack the coil down and fit it to the girdle’s shape as you move around the form. Let it sit for a minute, then paddle the coil to flatten its bottom edge (13). Remember, if there’s too much slip, the coil may slide around. Once the coil is flattened, roll the inner edge of the foot downward and toward the center of the plate with the pony roller (14). Roll the outer edge of the coil flat, then roll the inner edge downward again. Do this a couple of times until you’re satisfied with the shape. Don’t flatten the foot coil down too far; a higher foot allows for an inner foot ring that’s safe to glaze.
Use a firm-tipped clay shaper to make a channel beneath the outer edge of the foot all the way around, then insert the rubber rib into the channel on the short end of the foot and lever it up in the last effort to level the foot (15).
Use a wood tool to compress the seam edge between the girdle and the plate face, making sure the seam is well sealed. Smooth the edge of girdle with your finger to soften it. Use a rib to rub out any Surform or other tool marks.
Place a small board over the foot and press down gently but firmly in the center. Look between the inverted foot and the board. If there are any spaces through which you see light, readdress the foot before removing the plate from the mold. If no light is showing, flip the mold and the board back over. Remove the top board and lift the hump mold straight up off of the plate (16). Leave the plate on the board until it’s leather hard to lift without any distortion.
Place bath towels both under and over plates to slow down and even out the drying. For the first couple of days, particularly if it’s dry or hot in your studio, use plastic over the towels when away from the studio and remove the plastic when you can keep an eye on them. At this point, as a general rule, I try to forget about the plates for several days. During this early stage of the drying process, check the plate for warping and any separation at the joins. If the foot is warping, slow the drying down further. If any seams look suspect, compress with a wood or metal cleanup tool, then continue to slowly dry.
Once the plate is bone dry, if the foot is just a little wobbly, the glaze firing will likely level it out. If the dried foot has a significant wobble, gently slide it across a piece of sandpaper to level it out. A slow bisque is recommended for handbuilt plates.