Coil building is one of the oldest ways of making pottery, and it is still one of the most satisfying. You need clay, a flat surface and your hands, and you can make anything from a small pot to a tall vase. Here at the studio, handbuilding is at the heart of what we do, so we thought we would walk you through how coil building works.
what is coil building?
Coil building means making a form by stacking long ropes of clay, called coils, one on top of another. The coils are joined together and blended, so that the finished walls are one continuous piece of clay rather than a stack of rings.
It is a slow, thoughtful technique. Because you build up gradually, you can change the shape as you go, making a pot wider, narrower, taller or more irregular. That makes it a lovely method for organic forms that would be hard to achieve any other way.
what you need
- clay that is soft and well wedged, with no air pockets
- a smooth, non-stick work surface, such as a canvas-covered board
- a small bowl of water and a soft brush or sponge
- a fork or serrating tool for scoring
- a wooden or metal rib for smoothing
- a damp cloth and plastic sheeting to keep unused clay from drying out
step by step
1. make the base
Roll out a small slab of clay to an even thickness, around half a centimetre to a centimetre, and cut it to the shape you want. This will be the bottom of your pot. Alternatively, you can coil the base itself by spiralling a single coil round and round and blending the joins.
2. roll your coils
Take a lump of clay and roll it under your palms and fingers, working from the centre outwards, until you have an even rope. Aim for a thickness of roughly one to two centimetres, depending on the size of your pot. Even coils make even walls, so take your time and keep the pressure light and consistent. If the coil starts to crack or flatten, the clay is probably too dry or you are pressing too hard.
3. score, slip and attach
Where two pieces of clay meet, scratch both surfaces with a fork, add a little slip (clay mixed with water to the consistency of single cream) and press them together. This scoring and slipping is what makes a strong join. Lay the first coil around the edge of your base and press it down firmly.
4. blend the coils
This is the step that matters most. Using your thumb or a finger, smear the clay from one coil down into the coil below, working on the inside and the outside of the wall. Supporting the wall with your other hand as you work stops it from pushing out of shape. When you have blended thoroughly, the wall should feel solid and continuous.
5. keep building
Add coil after coil, scoring and slipping each time. To make the pot flare outwards, place each new coil slightly outside the one beneath. To bring it in, place each one slightly inside. Go gently when changing direction, and do not rush upwards: very wet, tall walls can slump under their own weight.
6. refine the shape
Once you are happy with the form, use a rib to smooth the surfaces and refine the curves. Some makers like to leave the coils visible as a decorative feature, and that is a perfectly good choice too. Just make sure the joins are still properly blended inside.
common problems and how to avoid them
- cracks at the joins: these usually come from joins that were not scored, slipped or blended well. Take a little longer on this step.
- walls that slump: let the pot firm up a little between sessions, or work in stages and allow the lower section to stiffen before adding more weight.
- uneven walls: check your coils are an even thickness, and feel the wall between your fingers as you work.
- air trapped in the clay: wedge your clay well before you start. Trapped air can cause problems during firing.
drying and firing
Handbuilt pots need to dry slowly and evenly. Cover your piece loosely with plastic so the moisture leaves gradually, then let it dry fully before firing. Pieces with thick and thin areas are more likely to crack, which is another reason to keep your walls even. After drying, a pot goes through a bisque firing and then a glaze firing, and the finished stoneware is strong enough for everyday use.
coil building compared with slab building
Both methods are handbuilding, but they feel quite different. Slab building uses flat sheets of rolled clay and suits crisp, structured shapes such as mugs, plates and boxes. Coil building suits rounder, more flowing forms. Many makers use both, even in the same piece.
tips for your first coil pot
- start small: a little pot or a simple cylinder is a great first project
- keep the clay at the same level of dampness throughout
- use plenty of patience on the blending, and do not worry if your first attempts are wobbly
- enjoy the process, because imperfections are part of what makes a handmade piece special
If you would like to try handbuilding with some guidance, our mug handbuilding workshop is a friendly introduction for beginners, using the slab method. And if you would rather enjoy the results of the craft, have a look at our shop, where you will find handmade stoneware like the seastone cup, finished in our speckled stone glaze.