This clip was excerpted from Beginning to Throw on the Potter's Wheel with Robin Hopper, which is available in the Ceramic Arts Daily Bookstore!
More Throwing Tips!
If you have taken the usual precautions after throwing and still have trouble with the bottoms of pots cracking, place the wedged clay on the wheel so the roll or spiral of the wedge is lying on its side, not on end. To ensure this alignment, pat the clay into a cone immediately after wedging. (If you use a pug mill and do not wedge your clay, place the pug on its side rather than on end.) This method can eliminate virtually all bottom cracks and is especially effective when throwing plates and large, flat-bottomed pieces.
Trimming the foot of a large-diameter plate or platter can be a problem. The pressure of the trimming tool tends to press the plate bottom down toward the bat. For plate support when trimming, try gluing a piece of firm foam, about 2 inches thick, to a bat. The foam is then trimmed to approximate the interior diameter of the plate foot. A leather-hard plate is then placed on the foam, which will not mar the surface, but will provide ample support while trimming.
A kitchen spatula with a wooden handle will make a variety of throwing tools. The hardwood handle, if sharpened to a point, is an excellent separating stick for removing clay from the base of a freshly thrown pot before it is cut from the wheel head or bat. The rubber part is equally useful as a rib, or it can be cut and sanded to form a decorating rib.
If your main form of exercise is wedging and throwing clay, try sitting on an exercise ball (yoga ball) to get a free workout at the wheel. I use a 65 to 75 centimeter ball, which sits in a stabilizing ring. The amount of inflation will determine the seated height. Both the ball and the ring were purchased from a sports equipment store. The ball is not only good for an abdominal workout but it also seems to work the lower back, glutes and inner thighs. Need a break? Just lie on your stomach over the ball. It really does give you a good workout. The first time I used it, I felt like I had been riding a horse all day when I got off!