I love throwing and trimming pots off the hump. It’s a versatile technique that fluidly integrates with my studio rhythms. I find that I advocate for throwing off the hump at every workshop. I use it for all forms that I plan to trim: bowls, cups, mugs, and plates, and a few small forms that don’t get trimmed. As with all methods, there are some tips that increase your success rate, and keep the learning curve from being so steep.
I usually wedge up 25 pounds of clay in four-part sections, and then pound these all into one lump on a bat placed on my wheel head and center just the top portion of the mound (figure 1). This becomes my working base. Working off a bat allows me to move my throwing hump when I want my wheel free for other forms. I throw and trim off the same hump. Throughout the day, as the pots made earlier start to set up, I reshape the throwing mound so that I can use it as a trimming chuck. When I have finished trimming, I reshape the same mound and return to throwing. The transition is fluid.
- I can see form better. The pots sit higher off the wheel head, allowing for me to see and shape more complete forms because they’re not cramped or shadowed by their proximity to the wheel head.
- Versatility of size. As with throwing right off the wheel head, I can make my pot smaller using a needle tool to take clay off the rim, but when I have access to a reserve of clay underneath I can also dig deeper and add volume and height seamlessly.
- Releasing form. Even before I take the freshly thrown pots off the hump, I start trimming the exterior of the foot, removing excess weight and completing lines (figures 2 and 3). Because the pot is up in the air, this is a comfortable process.
- Cutting off. Years ago Linda Christianson taught me how to make a twisted cut-off wire out of fishing line. It helps tremendously if you’re able to make a level cut under the thrown form. When I am ready, I make a small groove that encircles under the foot of the pot with my needle tool (figure 4). I then lay the end of the fishing-line wire tool in that groove and spin the wheel once around so the wire crosses over itself. Then I pull straight out on one side of the wire tool and it cuts a level cross section of the mound of clay. Because the fishing line is twisted it leaves a lovely shell-like mark that I can trim away or leave as a decorative choice. Dental wire and traditional wire tools don’t work well for this method, because as they cross over themselves they create a small loop that flips and turns, gouging the clay.
- Trimming. My throwing clay switches to a trimming chuck and back again whenever I need it to (figures 5 and 6).
Throwing off the hump does have some limitations. I don’t throw bottles, pitchers, or large jars off the hump because these forms aren’t trimmed. In fairness to accurate and unbiased reporting I made a list of reasons not to throw off the hump:
- You will make more pots.
- Your studio scale will begin to rust from disuse.
- Your friends will want you to teach them how.
- You might find yourself writing just such an article.
Simon Levin is a wood-fire potter from Gresham, Wisconsin, who dislikes writing about himself in the third person. He evangelizes for wood-firing everywhere, is a Fulbright Scholar, kiln builder, and writer, but foremost he loves making pottery and big hot fires. You can see more of his work at http://simonlevin.com.