Is clay recyclable?/ Can you recycle clay?
Yes, clay is infinitely reusable and recyclable, if done well it is a process that will save on the costs of purchasing new clay, and keep you fit along the way. It’s only once the clay is fired that it is more difficult to recycle. So, how do you recycle clay?
How to recycle clay: Divide The Clay Into Different Levels Of Dryness
To recycle clay it is useful to divide the clay into different moisture levels, we do it in 4 levels:
- Hard and Dry clay, that is no longer plastic or flexible.
- Soft Clay, like you would get out of a bag or from off-cuts.
- Wet Clay, which is soft clay with water on it.
- Clay Slops, such as the thickened clay water that collects during wheel throwing.
We treat each moisture level of clay differently, by dividing them in this way can reduce the amount of work involved in the clay recycling process. We keep buckets in the studio for clay slops, wet clay and dry clay, and finally then soft clay can be put straight back in a bag or kneaded right away.
Hard/Dry Clay
Hard and dry clay, that is no longer plastic or flexible, should be collected and left to fully dry out to the bone dry stage. This includes trimmings from turning, failed pots that are leather hard or bone dry, off-cuts from hard slabs, and shavings/debris from other hand-building processes.
Soft Clay
Soft clay, even if it’s dried a little, as long as it’s still plastic and flexible, can be kneaded into a clay block and reused right away. It does not need to go through the whole recycling process. Soft clay can include off-cuts from soft slabs, trimmings from soft clay pots, and clay lumps used to pin down thrown pots for turning.
Wet Clay
We put flopped pots from throwing on the wheel, if there are many, in their own bucket. Wet clay such as from pots flopping over on the potter’s wheel or pulling handles, as with soft clay, can also sometimes be kneaded into a firmer block of clay and be reused right away. However, when the quantity is too much or the clay too wet, it may stick to the kneading surface, making the process difficult. In this case it should be collected and left to dry out. This clay does not need to go through the whole recycling process either, it just needs to dry a little until firm enough to knead into a block.
Clay Slops
The thickened clay water that builds up while wheel throwing we call slops. It should be collected separately in a bucket. As this settles over a day or two the water can be pared off of the top of the bucket.
The Clay Recycling Process: Step by step
After dividing the clay into different moisture levels, the steps to recycle clay are:
1. Slake down the clay
Add the clay slops to the fully dried (bone dry) waste clay. Depending on the size of the clay pieces, soaking the dry clay will slake it down to a thick slurry in 1 day to 1 week. If it’s fine trimmings from turning, they can slake down quicker.
2. Put the clay slurry out to dry
The clay is given a good mix and put out to dry on plaster batts. The air and plaster together will help dry the clay. It’s dry enough when it won’t stick to a wooden board when it touches one, so it can be wedged. If left for too long the clay may be too firm to knead. It can take a couple of days to a couple of weeks to dry depending on how thinly it is spread, the weather, whether the kilns have been on, and the absorbency of the plaster batts.
3. Knead the clay
Once dry enough, it’ll be soft enough to knead. The clay is simply kneaded and wedged until it becomes a homogenous consistency. Kneading mixes in any harder lumps, and also removes air pockets. It’s then ready to throw and hand-build with.
What is Wedging?
Wedging is the process of kneading clay to make it into a homogenous consistency. Wedging does this by mixing and aligning the clay particles, and removing air pockets during the process. Read more on wedging.
Recycling clay
Recycling clay is an effortful process initially. When done inefficiently it may even be cheaper to sling your waste clay down a hill and buy some new bags of clay. However, how you recycle clay, by dividing the clay into different moisture levels, understanding when to do each stage of the recycling process, and your skill in wedging has progressed: it is something that is economically beneficial, helps keep you physically active encouraging good health, and is better for the environment. It’s a necessary step for any pottery studio especially community studios like ours that offer pottery classes.
