This post was excerpted from Pottery Throwing Tools: A Guide to Making and Using Pottery Tools for Wheel Throwing, which is free to Ceramic Arts Daily Subscribers.
Tips for Using Throwing Sticks
The first problem occurs when the shape sweeps out from the base and there is insufficient strength in the lower wall to support the weight of clay above it. This overhang is a weak point, and if formed early, the loping clay has a tendency to fold or collapse. While buttressing the base by making it thicker or adding a concave contour adds strength, these solutions negate any intention to achieve a spherical or ovoid form with a bold convex contour.
A second problem arises when the opening at the top of the form is too small to put your hand inside to stretch and shape the clay wall. The solution is to use a throwing stick (see PMI, Spring 2000), which allows you to expand the girth of the pot, avoid slumping and to finish the shoulder, collar and neck with an opening just wide enough to accept the throwing stick.
Begin with a well-wedged 6- to 10-lb. ball of clay. Throw a tall cylinder about three times higher than it is wide (figure 1). The walls should be relatively thick and uniform from top to bottom, and you should be able to get your folded hand inside and reach the base.
Draw the clay up to make a rounded shoulder using the inverted trumpet bell technique (figure 2). Remove excess water from the inside of the base, then collar the top to leave an opening just wide enough to insert the end of the throwing stick.
Hold the stick firmly in your left hand so that its head faces to the right (assuming your wheel turns counterclockwise). Practice moving the stick upward and outward and inward (figure 3), imitating in the air the track you anticipate to make inside the pot as you create your intended profile. Notice the shaft and its position in relation to the rim of the pot and think of the shaft passing though a narrow opening (see A).
When you feel familiar with the weight and movement of the stick, wet one end to lubricate it, then insert it into the neck and lower the head to the bottom of the rotating pot. Let the head rest against the rotating clay right at the base, and, with the wheel turning between half and quarter speed, stretch the clay slowly outward against your right hand, which provides support (figure 4). Tip: Palm a wet sponge in your right hand to supply lubrication. This prevents your fingertips from snagging the clay.
As the base of the wall moves outward, move the stick slowly upward until the profile merges with the curve of the shoulder (figure 5). Follow the new profile on the outside with only your right-hand fingertips or knuckle. Because the area of contact is small, drag is minimal and snagging, which might buckle the wall, is avoided. Try to keep the lubrication uniform inside and out.
Moving from the base and merging with the shoulder may need repeating several times until the two curves blend. If the pot has not achieved sufficient girth, stretch the belly wider on subsequent passes, but not too far (figure 6). Watch how the contour of your pot develops and pay attention to the shape.
Because the preliminary throwing process is designed to retain a mechanically strong wall from top to bottom, it’s possible to retain height and prevent the belly, toward the foot, from sagging (figure 7). In addition, throwing a thick wall at the top of the pot ensures that there is clay to form firm shoulders. If the initial cylinder wall had been tapered, there would have been insufficient clay to form the shoulder. The pot would have collapsed inward and lost height as the clay was stretched.
After expanding the body to its final form and refining the profile, the collar of clay at the top of the pot can be drawn up and shaped (figure 8). Use a rib to assist in blending the contours as they move from convex to concave. If there is sufficient clay, decorative treatments can be added to give character and shape. Note: Slight, controlled, but efficient lubrication reduces the degree to which your clay absorbs water, further enhancing the strength of the clay. Minimum contact with the clay reduces the twisting stress so the pot is less likely to collapse.
While learning to use a throwing stick, you may experience setbacks and failures, but don’t be disheartened! Size limitations are determined by the clay, your strength and controlling the moisture content. You may feel inept and awkward in the beginning, but as your skill develops through practice, you’ll find that you’ll eventually create pots of unquestionable merit.