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Published Jul 22, 2019

Grooved deep bowl, 10 in. (25 cm) in diameter, stoneware, fired to cone 10 in reduction.Potters and ceramic artists are very open minded when it comes to their tools. The general rule of thumb seems to be, if it's not nailed down, test it out as a pottery shaping tool — actually, even the nailed-down things have probably been considered. So when Frank James Fisher noticed a bunch of trim scraps at a local home center, his thoughts immediately went to “clay tool." He asked the lumberyard if he could have the scraps and they turned out to be a fun wheel throwing rib tool.

Today, Frank explains how he has turned these scraps into handy shaping tools. Next time you’re at a lumberyard, ask for some of the scraps and try them out. - Jennifer Poellot Harnetty, editor


I recently discovered several remnant pieces of wood molding from a past home remodeling project in my garage. I was especially intrigued by the concave and convex curves and ridges on the profile. It sparked my curiosity. What if a clay bowl were grooved along the rim with this profile? I sliced off a small cross-section of molding with my miter saw and thirty minutes later I sat at the wheel reveling in the groovy designs left by my new toy.

Anyone who has wandered the aisles of a home improvement center knows the range of molding styles and profiles is quite extensive. The store in my neighborhood allows customers to pre-cut their molding purchase at the store, so there's a cart in the molding/trim aisle that has a saw and a basket to collect the scraps. After asking, I was allowed to keep any small scraps from their scrap bin. My collection of molding tools quickly grew to a half dozen interesting profiles (figure 1). After a little experimenting, the different profiles brought a nice design feature into my work. The complex groove pattern complements the soft spiral I like to create in the basin of bowls and platters.

A selection of molding profiles suitable for use as ribs.

Several tool manufacturers produce a wonderful array of wood and metal profile tools for use with clay. But there are three interesting sculpting advantages that a scrap of molding can provide. First, the varied sizes of the ridges and the concave and convex curves of the profile can be very extreme. The molding is not made to carve perfect grooves into the clay. In fact, some of the nooks and crannies on the molding may not be mirrored successfully in clay since some details might be too deep to be captured. This can result in void areas in the band of grooves; however I don't mind these, as I like the variation and space that results. Sometimes the slurry creates interesting ridges in these void areas, which adds design interest.

Second, the molding profiles are sometimes dramatic, with large bulbous curves. When the clay rim is pressed along the surface, the full rim is shaped to match these major curves. The grooves are not just cut into the clay surface, but the shape of the clay rim follows the curve of the profile. The resulting rim can then be gently modified or exaggerated further depending on the desired effects.

The last advantage relates to clay thickness. Because the clay conforms to the molding profile, it does not need to be extra thick to accommodate deep recessed carving. When using a piece of molding, there will be thick and thin spots, but extra clay is not needed in the rim to compensate for the grooves. I throw a rim with an average thickness and let the clay follow the profile's shape.

Creating Grooves

Press the molding into the rim while supporting the outside.Begin by centering, opening, and pulling the clay into a standard bowl form, either tall or wide and open. To create grooves in the rim of the bowl, begin by wetting the rim surface, (inside and outside), with a damp sponge. Select a piece of wood molding that aesthetically fits the rim and determine which will be the top or bottom of the profile. Wet the wood molding profile and position it against the rim as the wheel slowly spins. Place your other hand under the rim on the outside surface (figure 2). This hand will support the clay as the wood molding is pressed down. Your fingers can also press the clay into the void areas of the molding. It is not critical that the entire rim come in contact with the full surface of the profile. The major ridges and high points will leave a groove. The result is a clay rim with a roughly uniform thickness. As the molding is pressed against the clay, the rim may also be tilted out and down or stretched outward to slightly open-up the bowl. If the ridges are too sharp or there are globs of slurry to clean away, use a sponge and smooth out the surface as the wheel rotates.

Clean and round the rim edge with a chamois. Create a shallow recessed slot with the chamois between your fingertips. Gently pinch and compress the clay on the rim edge. The edge of the rim is bent further downward in the same motion. A cross-section shows the angle of the rim as well as the depth of the grooves made in the rim by the profile tool. The angle created compensates for the upward curl of the rim as the clay dries and shrinks. The thrown bowl is wired free from the bat and trimmed as desired.

**First published in 2011.