Turning the base of a mug body, the step done before the handles are put on and pulled, like previously demonstrated in an older video.
I use a leather hard chuck, with a flat top, that I attach to the wheel-head. The benefit of this, compared to simply putting it straight on the metal wheel, or using a grip is as follows. The flat top rests perfectly against the interior base of my mugs, this means I can throw the bases thinly and turn them smooth without the bottoms collapsing or pushing inward to be concave. I lightly damp the top of the leather hard chuck before tap centring the pot into place, the moisture helps it stick firmly in place. I’ve kept the same chuck for almost a year now, after every session using it, and it can be used on multiple forms, I spray it with water and wrap it up tightly with plastic.
The other advantage is speed, I don’t have to remove the three lumps of clay and reattach them each time or loosen the grip holding it in place. They just go on and off. Lastly, the delicate rim isn’t damaged by being pressed against the metal, and there’s no way they can be distorted by pressing the three lumps of clay against it.
Tap centring is a skill I would recommend all throwers to learn, it speeds up centring anything on the wheel tenfold and after enough practice it becomes second nature. I learnt by simply using an old bisque fired bowl and spent an hour or so trying to do it, until it clicked. Of course overtime I’ve got better at doing it, but the basic know how comes very quickly.
Once in place I can go about trimming the base and sides and burnishing them with a kidney, like shown. I like the bases of my pots to be smooth and clean, the bevelled edge turned onto the corner not only adds a lovely shadow beneath the pot as it rests, but it also removes any sharp corners from the bottom, which might chip with use.
It’s a quick procedure for each but does add another whole step to creating these pieces that the Maze Hill Pottery mugs don’t have, they’re left with the wiring off marks on the bottom and the edge is simply gone over with a wet thumb to soften it. This is how I finish all of my pots off, save those with foot-rings.