Coil building is the oldest way to make a pot and still the most forgiving. No wheel, no centring, no getting three minutes in and watching the whole thing collapse. You roll ropes of clay, stack them, and smear them together. The trade-off is that a free-standing coil pot wants to lean outward as it grows, which is what the mould in this tutorial fixes.
Yvonne from Yvonne Ceramics builds inside a large salad bowl lined with plastic. The bowl holds the profile so the walls cannot slump, and the plastic lets the pot lift out cleanly once it firms up. It also means you can build bigger than you could throw on a wheel.
She shows both ways to make coils: by hand, and with a handheld extruder. New to clay? The pinch pot is the simplest start, and hand building pottery covers the three main methods. No kiln? Air dry clay takes the same coils.
What you need
- About 10 lb of clay for a mixing-bowl-sized pot
- A smooth bowl to build inside, plus plastic sheeting and tape
- A rubber rib, which does most of the real work
- A sponge, water, and a knife for cutting coil ends
- A board to flip the pot onto, and a turntable if you have one
- A handheld extruder, optional
Which clay to use
A grogged stoneware is the easy answer. Grog is ground-up fired clay mixed back into the body: less shrinkage, less warping, fewer cracks at the joins. Porcelain is the opposite, fine on a wheel and miserable in coils. Ask for a hand-building or sculpture body in a range your kiln can reach.
Rolling coils that come out even
Settle on a thickness first. Half an inch suits a bowl this size and every coil has to match it, because walls built from mixed diameters dry at different rates, and that is what pulls a pot apart on the shelf. Roll from the middle outward with your fingers spread; palms give you a coil fat in the middle and thin at both ends. An extruder hands you identical coils with no rolling.
Scoring and slipping, and when you can skip it
Clay pressed together without being welded comes apart, usually in the kiln, where the join opens into a line you cannot fix. Fresh soft clay bonds under firm pressure alone. Once it stiffens, or if you come back the next day, score both faces with a cross-hatch and brush slip in before you press. Slip is clay mashed with water to the thickness of yogurt.
Smooth walls or visible coils
Both are real finishes. Rib the outside flat and the pot reads as thrown. Leave the coils proud and the ridges say hand built, and they hold glaze better. Either way the inside gets welded shut, coil into coil. That is the structural step, not a cosmetic one.
Drying and firing a coil pot
Slow is the whole trick. Tent the pot loosely with plastic for the first few days so the rim, the thinnest part, does not dry ahead of the base. A big coil pot can take a week to reach bone dry, and that matters: water left in the wall turns to steam in the kiln and takes the wall with it. Bisque fire, then glaze if you want it watertight. For a garden planter, punch the drainage hole while the clay is soft.
Why coil pots crack
A crack along a join means the coils were never welded, or one had dried too far before it went on. Scoring fixes the first, plastic over your rolled coils fixes the second. A crack at the rim running downward is uneven drying: the rim shrinks while the base is still damp.
A base that splits across the middle was never compressed. A pot that has gone oval came out of the mould too early: press the rim with a finger before you turn it out, and if it flexes, give it another hour.
Use the leftover clay while the bag is open: roll the offcuts into clay ornaments. If the pot ends up outside holding a plant, a mosaic flower pot needs no kiln at all.
