RING MOLDS!

WHAT: These are closed hoops of fired clay that a slab is pressed into to create the floor of a form, then additional clay is added to the slab (while still in the mold) to develop the object vertically.

WHY: The use of a ring mold at the base of a form allows you to start with an idea, perhaps a sketch of a shape, and develop it into a form. It creates a clean, angled bottom portion on a form. It supports the vessel during the building process. It sustains the original intent of the object throughout construction.

HOW: A heavy coil of clay is rolled, between 1” - 2.5” in diameter (depending on the size of the final form). The ends of the coil are attached to each other to form a continuous ring. Then, shaping begins, working on a board on a turntable if possible, making circuits of the ring and changing the shape progressively. Once the initial shape is established, the ring is angled, or beveled, to slope inwards towards the center. A 1⁄2” platform (or so) is left at the upper outer edge of the ring (to support building later). Using ribs, the bevel and the shape are clarified, to your liking. Finally, the inner edge of the ring mold should be cleaned up with a knife, to remove the sharp edge.

The mold should be dried and fired before use. If in a hurry, perforate the ring with many deep needle holes (poked from the outside), to vent water.

Once fired, the ring mold is placed on a board, with newsprint underneath. A slab of clay, big enough to cover the whole mold, is laid in the mold. The slab should be about 50% thicker than you intend the final thickness to be. This slab is then coaxed into the mold, feeding clay from the outside into pockets. Once the general topography of the ring exists, you will begin compressing the floor slab with the pads of your fingers, from the center out, working in a spiral (a turntable is very helpful here). Keep pressing the slab down (and out), compressing the clay, until you reach the inner edge of the mold. Then, do the same process up the bevel of the mold, until you reach the 1⁄2” platform at the top. Once the slab has been conformed to the mold, trim extra clay from the mold, leaving about 1⁄2” inch of clay overhang (this is helpful for attaching the first coil or thick pinching slab in the next step).

APPLICATION: Now you can begin building up, or out, or in, with the floor slab remaining in the ring mold. It can stay there until dry, if wanted, only being removed after forming is done to clean the bottom of the object. You can even fire the piece in the ring mold, after ensuring it isn’t trapped.

TIPS:
-- Don’t get trapped! Be sure your floor slab can shrink away from the sides of the ring mold towards the center, or cracks will happen! This is a variation on the idea of undercuts (from mold-making), and takes a slight change of perspective to wrap your head around.
-- The term “mold” is only used in this case for simplicity. Ring molds can be used to create a new object every time, by changing what happens after the first, floor-shaping stage. The mold acts only a starting point!