I confess that from my perspective, throwing is far more satisfying than slip-casting.
I love the spontaneity and sense rhythm you feel when throwing. The first step is of course to prepare the clay for throwing. This is called “wedging” and is a process of kneading the clay to ensure a regular consistency and to eliminate any trapped air.
The clay is they made into a ball and thrown onto the centre of the wheel head. The next step is to “centre” the clay and it often surprises people how much strength / pressure is required to get that lump of clay running dead centre on the wheel without any wobbles!
The wheel needs to be turning fast and you need plenty of water for lubrication. Once centred you must create an opening in the top and drill down towards the wheel head but leave sufficient thickness for the base of the pot.
The hole is then opened up to create the inside diameter of the pot you want to make thus you have something that looks a bit like a doughnut. The walls of the pot are made by squeezing the clay between the fingers of your left hand (which is inside the pot at 4 o’clock) and the fingers on your right hand (which is outside the pot again positioned at 4 0’clock) as the clay spins. As you apply pressure you slowing lift your hands upwards and the clay pot will grow with your hands – this is the throwing process.
To counter-act the natural tendency for the pot to flare outwards (due to centrifugal force) it’s important for your hands to travel in an upwards and inwards motion – as if drawing a line on a cone.
This is repeated several times until the wall thickness is thin enough and even from top to bottom. By following this ‘cone line’ you should be able to maintain a cylindrical shape until such time that you want to create the final shape.
To create a bellied shape the fingers on your left hand (inside the pot) apply more pressure than the fingers on your right hand. To create a neck / narrower shape, the opposite is true – the fingers on your right hand outside the pot apply more pressure than those on your left hand.