How to Make a Coil Pot

Find a bowl whose inside profile you like the look of, and make sure it is smooth inside. Any ridges or moulded pattern will print themselves into your pot. A large plastic salad bowl from a discount shop is ideal.

Line the whole inside with plastic sheeting, leaving plenty of overhang. That plastic is doing two jobs. It stops the clay sticking to the bowl, and the spare at the edges wraps over the top to keep everything damp if you have to stop halfway.

Cut a strip of clay off the block and squeeze it roughly into a sausage with your hands first. Then roll it, working from the middle outward with your fingers spread, letting your hands travel apart as the coil lengthens.

Light pressure. Leaning on a coil flattens it into a strap instead of a rope. If a bulge appears in the middle it means there is more clay there, so roll that section on its own until it evens out.

Roll all your coils before you start building. Once you have one finished, wind it into a flat spiral on the bench like a sleeping snake, which makes it easy to store and easy to pick back up.

Cover them as you go, with plastic or a damp cloth. Rolling twenty coils takes a while, and the first ones will have gone leather-hard before you get to them otherwise, at which point they crack instead of bending.

Start at the centre of the lined bowl and wind the first coil outward in a flat spiral, pressing it down against the plastic as you go. When you reach the end of a coil, cut it at an angle with a knife and join the next one on.

If the clay is still properly wet you can skip slip and scoring between coils and just press them together. Once the clay starts to stiffen you do need to score and slip, or the joins open up in the kiln.

Once the base spiral is done, compress it flat so it is even, then start carrying coils up the wall of the bowl. Follow the curve of the mould and press each coil down and outward against the wall as you lay it.

Coils rarely come out exactly the right length. If one falls short, cut a small piece and add it in, then smear the join closed. Nobody will find it once the wall is smoothed.

Work a rubber rib around the inside, dragging clay down from one coil into the next until you cannot see where one ends and the next begins. Be firm about it. This is the structural step, not a cosmetic one.

Every gap between coils that you leave is a weak point and a place for air to sit. Both cause cracks later. Keep the clay wet enough to move while you do this, which is why the coils were kept under plastic.

A handheld extruder is the shortcut. Load a chunk of clay into the barrel, screw a round die onto the end and squeeze. Out comes a coil at a consistent diameter, far faster than rolling.

Support the coil as it comes out rather than letting it hang, and curve it around as it emerges. Small air bubbles sometimes appear in extruded coils and they are not a problem here, because the smoothing step works them out.

Leave the pot in the bowl for a couple of hours until the clay firms up enough to hold its own shape. Then put a bat or board over the top, flip the whole thing, and lift the bowl away.

Peel the plastic off carefully. This is the moment the plastic earns its place: without it the clay grips the bowl and there is no getting it out in one piece.

The outside still shows every coil. Work the rib across the surface until the ridges flatten out, going gently because the clay is still soft and it is easy to change the shape of the pot while you are trying to smooth it.

Work slowly and in stages. This is the longest part of the whole build, and rushing it leaves flat spots where you leaned too hard.

Go over the inside once more, then the outside with a damp sponge to take out the last of the rib marks. The surface will look wet at this stage, which is normal.

Then leave it alone. Dry it slowly under loose plastic for a few days so the rim does not dry ahead of the base and crack. After that it is ready for a bisque firing, and a coil-built pot like this makes an excellent garden planter left unglazed on the outside.