introduction: how can we embrace sustainability in pottery, and what makes reclaiming clay a vital practice for eco-friendly pottery enthusiasts?
in the world of pottery, sustainability is key. one of the best pottery sustainability practices for eco-friendly pottery is reclaiming clay. this process not only minimizes waste but also brings a unique quality to your creations.
the process of reclaiming clay
1. collecting clay scraps: keep all your clay scraps in a designated container. as a solo ceramic artist, I don't produce a lot of clay scraps in one sitting, so I find that these plastic paint cans work well. clay scraps include trimmings, dried bits, failed projects, and any solid pieces of clay collected in your splash pan. you can also choose to keep your clay scraps separated based on the type of clay or have a mix of all the scraps together. I find it easier to keep them all together. just make sure you run a test tile of the clay mix before you glaze a full piece since the co-efficient of thermal expansion (CTE) will be different for a mix of clays than for a single ceramic body (more on this in a later post). if you used underglaze or mason stains in your process, you can reclaim this clay as well. underglazes and mason stains are basically just colored clay/ colorants. other types of glazes are more comparable to liquid glass, and should not be mixed in with the unfired clay. on this vase, I incorporated mason stains prior to the first firing and then a metallic glaze on the rim before the second firing. only the mason-stained clay can be reclaimed before the first firing.
a word of caution & some terminology
you cannot reclaim clay after the first firing. the first firing in the pottery process is called the "bisque firing." this initial firing transforms the clay into a porous, yet hard and permanent form, known as "bisqueware." this stage is crucial as it prepares the pottery for glazing, ensuring that the glaze adheres properly in the subsequent firing.
2. break it down: tear the clay into smaller pieces before adding it to the scrap bucket. if the clay has completely dried out (e.g. that one piece you threw weeks ago and forgot about on the back of some shelf), you will need to break it apart into smaller pieces with a hammer before adding it to the scrap bucket. it is important to break up the clay into smaller pieces of clay before rehydrating it. smaller pieces of clay expose more surface area to water. this allows the clay to absorb moisture more evenly and efficiently, ensuring a consistent texture throughout the material. larger, thicker chunks of clay can take a long time to absorb water and may not do so evenly, leading to hard spots within the clay.
3. rehydrating the clay: once your scrap bucket is full, soak the scraps in water until they're fully saturated. the amount of time it will take for the clay to rehydrate depends on the amount in the bucket. the smaller the bucket, the less time it will take.
4. mixing the reclaimed clay: after the clay has absorbed enough water, use a mixer to get the rehydrated clay as close to a homogenous consistency as you can.
5. drying: the next step is to lay out for drying on a plasterboard or a standard, white drywall patch. both are excellent for this purpose because they absorb excess moisture evenly, helping the clay reach the right consistency for throwing.
6. spreading the clay: spread the wet clay evenly across the surface of the plasterboard. the thickness of the layer should be consistent to ensure uniform drying.
7. observing the drying process: keep an eye on the clay as it dries. plasterboards will draw moisture out of the clay, and you'll notice the color of the clay changing as it loses moisture.
8. flipping the clay periodically: to ensure that the clay dries evenly on all sides, it's important to flip it periodically. wait until the edges of the clay start to lift up off the board, indicating that it's starting to dry, and then carefully turn it over. these plastic paint scrapers are a great tool that will make the flipping process much easier. you might need to do this several times, depending on the thickness of the clay and the humidity of your environment. I usually set a timer to check on the clay every 30 minutes, although if the clay is very wet and is not changing consistency quickly, you may find that you do not need to check on it as frequently for the first few hours. it is still a good idea not to leave it for too long because if it gets too dry, you are back to square one and will have to run the process all over again.
9. checking the consistency: after each flip, feel the clay to check its consistency. it should be firm but still pliable – too dry, and you will have to start the process again; too wet, and it won't hold its shape. you'll know if the clay is too dry if it lacks plasticity: plasticity refers to clay's ability to change shape without cracking or breaking. dry clay lacks this essential characteristic, making it challenging to shape or work with.
10. re-wedging: once the clay reaches the desired consistency, it’s ready to be re-wedged. this process further homogenizes the clay and removes air bubbles, preparing it for use in your pottery projects. wedging clay will be covered in a later blog post.
11. storing reclaimed clay: store your clay in a heavy-duty plastic bag for optimal protection. if a heavy-duty plastic bag isn't available, drop cloths are a suitable alternative, provided you wrap the clay thoroughly. additionally, the drop cloth can be repurposed to cover drying pieces, making it a reusable and versatile tool in your pottery toolkit. in addition to wrapping up the clay, you should store your clay (reclaimed or not) in an airtight container to keep it pliable and ready for use. I use these buckets with airtight, screw-on lids. I prefer them to the lidded buckets that snap close. if you have one with a snap closure, I highly recommend keeping one of these tools on hand to help you open it. generally, if properly stored, clay (reclaimed or not) can last indefinitely.
honorable mention
the pugmill. pugmills are a valuable asset in the pottery studio, streamlining the clay reclaim process by efficiently blending reclaimed clay. the pugmill operates by pulling clay into the machine, where it undergoes compression and vacuuming. this process efficiently eliminates air pockets and ensures a uniform clay body. the clay is then smoothly extruded from the opposite end, ready for use in pottery projects. however, their usefulness comes with considerations of maintenance and financial investment. regular upkeep is crucial to ensure they function effectively and last longer. additionally, the initial cost of acquiring a pugmill, along with its ongoing maintenance expenses, can be significant. also, there's the matter of having the space for it. therefore, while pugmills offer considerable time and effort savings, they require a thoughtful investment in both upkeep and budget.
conclusion
reclaiming clay is not just an act of recycling; it’s a statement of sustainability in pottery. by incorporating these steps into your practice, you not only save resources but also contribute to an environmentally conscious community of potters.