Watch your hands while they rest lightly against the spinning clay. If they pulse inward and outward with each revolution, the mass is still off center. Surface rings alone do not tell you that: centered clay can have throwing lines while turning steadily.
Loose clay, loose bat or uneven lump?
Stop the wheel and inspect the attachment. Clay sliding as a whole needs to be attached again; pressing on the upper lump will not repair an insecure connection. If you use a bat, check that it sits firmly rather than rocking on its pins or attachment system. A loose bat makes a clay problem look like a machine problem.
If the unloaded wheelhead or bat visibly wobbles, stop and inspect the equipment according to its manual. Keep hardware checks separate from clay practice, and never adjust rotating parts while the machine runs.
Support your arms
Position the seat so you can support your arms without reaching. Unsupported hands often follow the bump outward and then push back, recreating the same movement every revolution. Supported hands can maintain steady resistance as the clay moves into alignment.
Use clay with an even consistency. A hard patch inside a soft lump changes the resistance under your hands. If you cannot comfortably contain the portion, start with less clay.
Check the skirt and the top
Inspect the lower skirt where the clay meets the bat as well as the smooth top. An uneven base can remain beneath a centered-looking crown. Light hand contact helps you locate the movement without squeezing the mound into a new shape.
Apply and release pressure gradually. Pulling a hand away abruptly can disturb clay that was becoming stable. If drag develops, moisten the contact area rather than flooding the wheel. Excess water can soften the outside while the inside remains firmer, giving you a misleadingly slippery surface.
When to start opening
Ease your hands away gradually. If the mound stays steady, begin opening; repeated centering passes can add water and soften a surface that was ready.
If the wobble returns at the moment you release, practice that release on another small portion. If it persists throughout contact, ask an instructor to watch your arm support and pressure. These are different observations and need different corrections.
Questions about this topic
Can I center clay that is too wet?
You may be able to shape it, but very soft clay can respond unpredictably and become harder to control. Use evenly prepared clay instead of trying to solve excessive softness with more pressure.
Does coning have to be repeated a fixed number of times?
No. The useful result is consistent, centered clay. Repetitions are not a guarantee, and prolonged working can create other problems.