Keep prepared clay damp and covered in a bin or clay-lined pit, age it for 1-3 months if you can, wedge it on a waist-high, slightly absorbent table of plaster, stone or canvas-covered wood, and clean the area wet. Dried clay dust carries fine silica that harms the lungs, so the clay area is washed and mopped, never swept dry.
Part of Workshop & Forge Design
Clay storage and preparation is the wet end of a pottery studio: the bins that hold raw and aged clay, the table where it is wedged and the bucket where scraps are reclaimed.
The Wet Zone Is Planned Around Moisture And Dust
The workshop guide describes clay preparation as messy: a separate area with a wedging table (plaster, stone or concrete top for kneading), water access, a place to store raw clay, and a reclaim bucket for slop water and trimmings. Preparation itself is covered in the pottery guides (Pottery Clay Preparation, Wedging); this article places it.
Three things drive the layout. Clay must stay at one moisture, so it is stored sealed. Clay improves with age: the preparation guide gives 1-3 days to even out moisture, 1-2 weeks for plasticity to improve noticeably, 1-3 months for a significant gain and 6 months or more for the maximum, so there must be space for clay that is resting. And the wedging surface should be at a height where straight arms press down with body weight, with a slightly absorbent top that stops the clay sticking.
Worked Example: Clay For One Firing
Inputs: a permanent updraft kiln takes 20-40 medium pots a firing (Kiln Building); an average medium pot is taken as 1.5 kg of wet clay (an assumption for the example; weigh a real pot); wet plastic clay is taken as about 1,900 kg/m³ (a recalled figure for plastic clay, to be checked by weighing a known volume).
- Clay per firing = 20 × 1.5 = 30 kg to 40 × 1.5 = 60 kg.
- Volume = 30 ÷ 1,900 = 0.016 m³ (16 L) to 60 ÷ 1,900 = 0.032 m³ (32 L).
- Clay in the ageing store. At one firing every 2 weeks and 3 months of ageing (about 6 firings), the store holds about 6 × 32 L = 190 L at the upper end, so several lidded bins or a lined pit, not a single jar.
What You Need
- Lidded bins, clay-lined pits or sealed pots for damp clay
- A wedging table at waist height, with a plaster, stone or concrete top, or a canvas-covered one (Wedging)
- Water from a tap or a bucket, and a drain, sump or soakaway for slop
- A reclaim bucket for trimmings and slip
- Damp cloths or hide for wrapping clay
- Mops and buckets, not brooms
Method: Set Up The Wet Zone
Step 1: Floor it. A washable floor with a fall to a drain or a sump; the studio guide asks for the wet zone to be distinct (Pottery & Ceramics Studio).
Step 2: Place the storage bins against a cool wall out of the sun, in the shade, so they stay moist.
Step 3: Place the wedging table at the middle of the zone with room to press down with straight arms.
Step 4: Reclaim scraps in the bucket, let the water settle, drain it and spread the thick clay on a plaster slab, canvas or board to stiffen before wedging.
Step 5: Wrap prepared clay tightly in damp cloth and label the date.
Step 6: At the end of each session, wipe the table and the floor with a damp cloth or mop.
Common Mistakes
- Sweeping dry clay. It lifts the dust into the air.
- Leaving clay uncovered. It dries to a crust and is hard to bring back.
- Using a smooth metal or plastic top. The clay sticks.
- Dumping slop near a well or spring. Keep slop water and clay away from drinking-water sources.
Safety
Silica dust
Dried clay and many glaze ingredients carry fine silica, and breathing it over years scars the lungs; the damage is silent until it is advanced. Wet the work, mop, do not sweep, and keep dry mixing outside or in a place with a wind through it. A cloth over the mouth is poor protection against fine dust, so the real control is not raising the dust at all. Do not eat or drink in the clay area.
What’s Next
- Learn next: Kiln Placement & Safety — where the clay goes next
- Combine with: Clay Testing — knowing the clay before you store a ton of it