Slamming clay onto the wheel head properly is a crucial step in the pottery-throwing process. It ensures the clay sticks well to the wheel, reducing issues during centring and shaping.
Prepare the Clay: Start with a well-wedged, even, and round shape of clay. This prevents air from getting trapped beneath the clay when slammed down. An even shape also aids in initial centring, reducing wobble when the wheel spins.
Positioning the Clay: Place the clay roughly in the centre of the wheel head. If you're using a lump with an irregular shape, it will spin and wobble, making the centring process more challenging. Aim to use clay shaped into spheres or with a rounded base and a conical top for better stability.
Slamming Down the Clay: Aim to throw the clay as accurately as possible into the middle of the wheel head. Slam it down firmly to ensure it adheres well to the wheel head. The force helps the clay to stick and reduces the chance of it coming loose during the throwing process.
Using Wheel Head Rings for Alignment: Many wheel heads have concentric rings that can be used as guides to centre the clay. After slamming the clay down, spin the wheel to observe the gap between the clay and the rings. Adjust the clay's position by pushing it away from where it's closest to the ring until the gap is even all around. This step doesn't have to be perfect but getting it as centered as possible now will make the next steps easier.
Patting the Clay: Once the clay is as centred as possible, you can pat it into shape to further refine its position before starting the centring process with water.