In a community studio, managing and processing reclaim can be a full-time job. One owner, looking for an efficient solution, added a floor-heating unit to his plaster table to better manage the needs of the studio.
No potter is a stranger to the time- and energy-intensive process of reclaiming clay, ensuring no usable materials are wasted. When running a busy community teaching studio, the struggle is only multiplied. For example, at Midway Clay in St. Paul, Minnesota, at least 80–90 potters come through its doors on a weekly basis. This is where a heated plaster table comes in—a simple, innovative tool that will slide seamlessly into your current reclaim process—accelerating the time for sloppy reclaim to become usable clay and reducing the amount of waste produced.
Benefits of the Heated Bat Process
At Midway Clay, before the owner Phil Raskin developed and built the heated bat, members strained liquid clay reclaim through a layer of hardware cloth, stretched in a wooden frame, and lined with two sheets of muslin, to dry the clay to a consistency where it could be mixed into the rest of the reclaim. While this process worked, it took a long time—two to three weeks before the clay was dry enough—and it never dried evenly, resulting in crispy edges and non-homogeneous clay that took more effort to mix and prepare for subsequent use. With the new heated bat method, throwing water is transformed into usable clay in roughly one week.
Building the Heated Bat
Before you begin, it is worth noting that the exact table measurements we used when building aren’t particularly important, as the height and overall size of the table can be adjusted depending on your preference, space, and material constraints. What is important is that the bed of the table is roughly 3–4 inches (7.6–10.1 cm) deep to hold the heating element and plaster.
This table was built with a plywood top (24 × 43 inches (0.6 × 1 m)), 2 × 4 legs and cross pieces, and a 1 × 4 attached to the plywood top to make a cradle for the plaster. It was built with pine, but any material you have available will work.
The bottom of the table bed area is first lined with a layer of foam core tile backer board—any type from big-box lumber or tile setting stores will do, just ensure it is foam core rather than the traditional cement. This layer not only insulates the bat but also helps distribute the heat more evenly and directs it upwards through the plaster layer.
The table and plaster will be heated with a floor-heating unit, such as the ones typically used in bathroom renovations. Be sure to select one small enough to fit your table frame. It can be difficult to find the correct size if you have a small table—the one used in the pictured construction was purchased from Warmly Yours (www.warmlyyours.com). This unit is then installed directly on top of the foam core and connected to a high-quality thermostat. Follow the manufacturer’s recommendations for installation on the backer board (1). This unit was installed with hot glue, starting at one end and ensuring the mat stayed taut and flat as each section was glued down. If the unit is not properly and sufficiently secured, it may float up when the plaster is poured. Be sure to add the extra sensor to the heating component, as they do go bad occasionally.
Once the heating unit is properly installed, painter’s caulk should be used to seal each edge where the 2 × 4s connect with each other, to prevent leaking (2). Ensure the table is sufficiently level on the floor, then pour freshly-mixed plaster directly on top of the heating unit (3). If you already have a preferred type of plaster to use in your reclaim bats, any type will work. Here, a basic, generic pottery plaster is used. Mix enough plaster, following the manufacturer’s directions, to fill the table bed with a thickness of roughly 2–3 inches (5–7.6 cm). When the plaster has been poured, gently rock the table back and forth for roughly 3–5 minutes, to help any bubbles rise to the top and even out. Here, a six-inch putty knife was used to further finish and smooth the surface (4). Once the plaster is poured and smooth, it can take a few days for it to fully dry (5). Once it is set, your new heated table is ready for use.
From Throwing Water to Usable Clay
Midway Clay often goes through 10 gallons of water per class, or at least 60–80 gallons per week.
This reclaim process is specifically designed to reduce the waste produced when throwing water, typically full of clay bits and a thin slip material, is tossed down the drain. When students are finished throwing, their dirty water is poured into large, sturdy plastic trash bins that are protected with ¼-inch hardware cloth stapled across removable wooden frames, sized to rest snugly atop the bins. This protective layer is designed to catch sponges or tools left in the throwing water, and help separate and homogenize the thick sludge that often forms on the bottom of individual water buckets. Each day, the frame is lifted in order to siphon excess water off the top of the bins, as larger clay particles settle toward the bottom while clear water rises to the top. The clean water that remains is saved in a bucket to be continually reused for throwing and mopping the floor.
The remaining clay sediment is then mixed with a drill and a large paint mixer attachment and blended into a smooth paste (6). This new mixture is then poured into another straining frame, again constructed from ¼-inch hardware cloth stapled frequently across 2 × 4s, that has now been lined with two layers of muslin cloth or old cotton sheets (7). This frame should be sized to rest snugly over a large plastic container (here, a concrete mixing tub is used). Then, full of the smooth clay mixture, it is placed over the tub and left for three to four days with a small fan on it. The muslin sheets filter water out of the mixture extremely well, filling the tub with completely clear water that will be reused for throwing.
Once the clay mixture has been drained for the appropriate length of time, the muslin containing the firmer slip is lifted onto the heated table, which is set to roughly 90 degrees. The table remains at this temperature, covered with the muslin-sandwiched clay mixture, for roughly 2–3 days, depending on the humidity levels. In the summer, a dehumidifier or fan is placed nearby to help speed up the process.
When the clay is the appropriate texture, it is removed from the bat and is ready to be pugged or wedged into usable clay. At Midway Clay, it is added to the clay mixer and pugmill along with the dryer reclaim from trimming scraps or discarded pots, which have been roughly broken up into smaller pieces. However, there is no reason that clay removed from the heated bat couldn’t be wedged up on its own.
After the clay is removed from the table, the element is allowed to continue heating, preparing for the next round of reclaim. Because plaster becomes saturated and can only hold so much moisture at a time, traditional plaster bats would need extended lengths of time to fully dry out before they can be used again while this heated bat only needs about one day.
Note: This process requires some electrical work to wire in the warming mat and controller. No electrical advice is given here. You should defer to an electrician for advice on proper wiring.
the author Clara Wodny, currently based in Duluth, Minnesota, is a freelance journalist, potter, and printmaker. She is a 2025 graduate of Luther College in Decorah, Iowa, where she studied creative writing and graphic design, but really spent most of her time experimenting in the clay studio.
We understand your email address is private. You will receive emails and newsletters from Ceramic Arts Network. We will never share your information except as outlined in our privacy policy. You can unsubscribe at any time.
Please enjoy this complimentary article for the month.
For unlimited access to Ceramics Monthly premium content, please subscribe.
We understand your email address is private. You will receive emails and newsletters from Ceramic Arts Network. We will never share your information except as outlined in our privacy policy. You can unsubscribe at any time.
Subscribe to Ceramics Monthly
In a community studio, managing and processing reclaim can be a full-time job. One owner, looking for an efficient solution, added a floor-heating unit to his plaster table to better manage the needs of the studio.
No potter is a stranger to the time- and energy-intensive process of reclaiming clay, ensuring no usable materials are wasted. When running a busy community teaching studio, the struggle is only multiplied. For example, at Midway Clay in St. Paul, Minnesota, at least 80–90 potters come through its doors on a weekly basis. This is where a heated plaster table comes in—a simple, innovative tool that will slide seamlessly into your current reclaim process—accelerating the time for sloppy reclaim to become usable clay and reducing the amount of waste produced.
Benefits of the Heated Bat Process
At Midway Clay, before the owner Phil Raskin developed and built the heated bat, members strained liquid clay reclaim through a layer of hardware cloth, stretched in a wooden frame, and lined with two sheets of muslin, to dry the clay to a consistency where it could be mixed into the rest of the reclaim. While this process worked, it took a long time—two to three weeks before the clay was dry enough—and it never dried evenly, resulting in crispy edges and non-homogeneous clay that took more effort to mix and prepare for subsequent use. With the new heated bat method, throwing water is transformed into usable clay in roughly one week.
Building the Heated Bat
Before you begin, it is worth noting that the exact table measurements we used when building aren’t particularly important, as the height and overall size of the table can be adjusted depending on your preference, space, and material constraints. What is important is that the bed of the table is roughly 3–4 inches (7.6–10.1 cm) deep to hold the heating element and plaster.
This table was built with a plywood top (24 × 43 inches (0.6 × 1 m)), 2 × 4 legs and cross pieces, and a 1 × 4 attached to the plywood top to make a cradle for the plaster. It was built with pine, but any material you have available will work.
The bottom of the table bed area is first lined with a layer of foam core tile backer board—any type from big-box lumber or tile setting stores will do, just ensure it is foam core rather than the traditional cement. This layer not only insulates the bat but also helps distribute the heat more evenly and directs it upwards through the plaster layer.
The table and plaster will be heated with a floor-heating unit, such as the ones typically used in bathroom renovations. Be sure to select one small enough to fit your table frame. It can be difficult to find the correct size if you have a small table—the one used in the pictured construction was purchased from Warmly Yours (www.warmlyyours.com). This unit is then installed directly on top of the foam core and connected to a high-quality thermostat. Follow the manufacturer’s recommendations for installation on the backer board (1). This unit was installed with hot glue, starting at one end and ensuring the mat stayed taut and flat as each section was glued down. If the unit is not properly and sufficiently secured, it may float up when the plaster is poured. Be sure to add the extra sensor to the heating component, as they do go bad occasionally.
Once the heating unit is properly installed, painter’s caulk should be used to seal each edge where the 2 × 4s connect with each other, to prevent leaking (2). Ensure the table is sufficiently level on the floor, then pour freshly-mixed plaster directly on top of the heating unit (3). If you already have a preferred type of plaster to use in your reclaim bats, any type will work. Here, a basic, generic pottery plaster is used. Mix enough plaster, following the manufacturer’s directions, to fill the table bed with a thickness of roughly 2–3 inches (5–7.6 cm). When the plaster has been poured, gently rock the table back and forth for roughly 3–5 minutes, to help any bubbles rise to the top and even out. Here, a six-inch putty knife was used to further finish and smooth the surface (4). Once the plaster is poured and smooth, it can take a few days for it to fully dry (5). Once it is set, your new heated table is ready for use.
From Throwing Water to Usable Clay
Midway Clay often goes through 10 gallons of water per class, or at least 60–80 gallons per week.
This reclaim process is specifically designed to reduce the waste produced when throwing water, typically full of clay bits and a thin slip material, is tossed down the drain. When students are finished throwing, their dirty water is poured into large, sturdy plastic trash bins that are protected with ¼-inch hardware cloth stapled across removable wooden frames, sized to rest snugly atop the bins. This protective layer is designed to catch sponges or tools left in the throwing water, and help separate and homogenize the thick sludge that often forms on the bottom of individual water buckets. Each day, the frame is lifted in order to siphon excess water off the top of the bins, as larger clay particles settle toward the bottom while clear water rises to the top. The clean water that remains is saved in a bucket to be continually reused for throwing and mopping the floor.
The remaining clay sediment is then mixed with a drill and a large paint mixer attachment and blended into a smooth paste (6). This new mixture is then poured into another straining frame, again constructed from ¼-inch hardware cloth stapled frequently across 2 × 4s, that has now been lined with two layers of muslin cloth or old cotton sheets (7). This frame should be sized to rest snugly over a large plastic container (here, a concrete mixing tub is used). Then, full of the smooth clay mixture, it is placed over the tub and left for three to four days with a small fan on it. The muslin sheets filter water out of the mixture extremely well, filling the tub with completely clear water that will be reused for throwing.
Once the clay mixture has been drained for the appropriate length of time, the muslin containing the firmer slip is lifted onto the heated table, which is set to roughly 90 degrees. The table remains at this temperature, covered with the muslin-sandwiched clay mixture, for roughly 2–3 days, depending on the humidity levels. In the summer, a dehumidifier or fan is placed nearby to help speed up the process.
When the clay is the appropriate texture, it is removed from the bat and is ready to be pugged or wedged into usable clay. At Midway Clay, it is added to the clay mixer and pugmill along with the dryer reclaim from trimming scraps or discarded pots, which have been roughly broken up into smaller pieces. However, there is no reason that clay removed from the heated bat couldn’t be wedged up on its own.
After the clay is removed from the table, the element is allowed to continue heating, preparing for the next round of reclaim. Because plaster becomes saturated and can only hold so much moisture at a time, traditional plaster bats would need extended lengths of time to fully dry out before they can be used again while this heated bat only needs about one day.
Note: This process requires some electrical work to wire in the warming mat and controller. No electrical advice is given here. You should defer to an electrician for advice on proper wiring.
the author Clara Wodny, currently based in Duluth, Minnesota, is a freelance journalist, potter, and printmaker. She is a 2025 graduate of Luther College in Decorah, Iowa, where she studied creative writing and graphic design, but really spent most of her time experimenting in the clay studio.
June/July/August 2026: Table of Contents
Must-Reads from Ceramics Monthly
Unfamiliar with any terms in this article? Browse our glossary of pottery terms!
Click the cover image to return to the Table of Contents