Wedging And Centering Large Amounts of Clay

If you struggle with centering clay—especially in large amounts— this post is just what you need. Claire O'Conner gives great advice on how to center clay for throwing large!

centering large amounts of clay

Centering large amounts of clay is something that I put off for a long time. I just didn’t think my wrists could handle it.  But I have learned over the years that learning how to center lots of clay doesn’t require brawn. It requires brains!

In this post, Claire O’Conner has a number of great tips for those learning how to center clay on the pottery wheel–especially if you want to center a lot of clay. She also gives advice on wedging clay in large amounts.  – Jennifer Poellot Harnetty, editor.

Selecting and Wedging Clay for Centering

Experiment until you find a clay body that works for you. If you’re throwing large pots, try using softer clay and throw it dry (or with less water) to avoid degenerating it to mush.

Wedge using the weight and strength of your whole body on a wedging table of the proper height. Ideally, the table height should be equal to the distance between fingertips and floor (figure 1). If that’s not available, raise your body using an aerobics riser or wide, heavy cinder block. Or you can move down to a clean cement floor and wedge as usual. Now that you’re down here, or up there, you’re ready to wedge. Bernard Leach (A Potter’s Book) was confident potters could wedge up to 30 pounds of clay. I say 20 pounds is more manageable. The hardest part is getting the spiral or ram’s head started. So start smaller, with about 5 pounds, and periodically add in 1–2 pound slices (figure 2).

Five Great Pottery Wheel Throwing Techniques

Amp up your throwing skills when you download this freebieFive Great Pottery Wheel Throwing Techniques.

Wheel Throwing Posture

Posture at the wheel is important. Sitting at the level of the wheel head (or slightly higher), as close to the wheel as you can get, with a straight back, and arms locked on your body is healthy, safe, and makes efficient use of bone, muscle, and gravity. You can also prop or mount a mirror in front of you to avoid resorting to the hunched-over side view to see the lower profile of your pot. Some (including potters, their mothers, and their health-care providers) swear that throwing standing up or using an alternative sitting position like a raised seat and/or raised wheel is best. If there are no extenders available for your wheel, cinder blocks or a platform built to your needs will do the trick. Some who use a stand up pottery wheel find that positioning their back against a wall provides a brace and more strength. Standing on a foam rubber floor mat minimizes stresses on legs and feet.

Centering Large Amounts of Clay

Whether sitting or standing, it’s important to learn how to center clay smartly. Many people firmly slap a revolving lump of clay to adhere it to the wheel head or bat. With several extra rotations and firm, open-handed slaps (always aimed in and down) you can also accomplish a lot of the early centering (figure 3). Your next step is to press firmly with your fingers on the base of the slowly rotating lump of clay (figure 4). This helps fix the clay onto the wheel head and, with several extra rotations, can do some of the centering. The final centering comes next. If you’re standing, brace your elbows against your abdomen. If you’re sitting, place your left foot up on a brick to keep your thigh parallel to the wheel head and high enough to brace your elbow against it. Brace your right arm against your right leg, and you’re ready to center. It’s important to move your body as a unit so that you have more leverage over the clay.

Press in on both sides to move your clay into a cone shape (see figure 6), and lean in, using your body weight to press the cone down. This process of creating and then flattening a cone shape aligns the clay in a spiral shape, and makes it more workable. At this point you can either begin throwing or you can go bigger by adding a cone-shaped mass to the top of this first piece of centered clay, slapping it into shape and closer to centered (figure 5). After securely connecting the two, press in from both sides to shape the whole mass into a cone (figure 6), then press down on it to compress, widen, flatten, and finish the centering for the whole mass.

Centering the base of a large mound of clay is hardest part of learning how to center clay in large amounts. So, without shame or embarrassment, grip your wooden potter’s knife firmly in both hands with the tapered edge held parallel to the clay and positioned slightly above the uncentered section. With the wheel spinning, slowly move the tool down into the uncentered clay, making a small groove, and follow the groove to the wheel head to shave off the bumpy stuff. With your mass now centered, flattened, and broadened to the intended final dimension of the base, create a center hole using your thumbs or two fingers.

Despite what you see on some YouTube videos, always keep your hands together when opening the floor of the pot after creating the center hole and whenever possible as you are pulling up the walls while throwing. Remember, the parts of smart potters’ bodies work as coordinated units. I find the best opening position is both hands at 6 o’clock. In most cases, my left hand is relatively passive with my right hand doing most of the pressing and pulling. If you are left handed and your wheel spins clockwise, reverse this order.

Do you have any tips on how to center clay in large amounts? Share them in the comments below!

Claire O’Connor teaches pottery for children, adults, and senior adults. She has graduate and undergraduate education in anthropology, educational psychology/adult education, and ceramics. She currently has a studio at the Northern Clay Center in Minneapolis, Minnesota. 

**First published in 2015
  • Claire O.

    In May, 2013 Merci Weitzen
    Saluda, NC posted, in response to my PMI article on throwing big.
    ” Hi Claire,
    What you recommend in step 3 is madness if you want to preserve your wheel and its electrical mechanisms.”
    These many years later and another of many postings of the same article I am still mystified why someone would use “madness” to describe the work (and writing) of another potter. My way of working comes from many years of experience It is definitely not the only or definitive way to shape clay. And, It is not “madness”. The alternative you suggested does (I am sure) work for you and others – none of whom are mad. Maybe the motive for your response comes from your concern for my wheel. So here I will assure you that my wheel, now more than 10 years old, is doing good work and doing it well.
    Claire O’Connor 8/2019

  • Bonnie S.

    Hi all, Here I am at 93 and while still working, my time at the studio has dwindled to the extent of my energy level. Sure gets tough to do what is in one’s mind and the body just won’t listen. I have found that hand building through using press molds that I made some time ago as well as wooden matched salad bowls I purchased at the wooden shoe factory in Holland, MI, way back then. Such a joy, just have to pinch off some clay, use as is, or shape it depending upon the desired finish. Press it into place in the mold and press and join the new clay to the previously placed piece. Pretty soon you have something going. I then join the two “bowls” made from the molds and then have a new shape to work with. I leave a hole in the one side and add a slab neck or coils, whatever, add a foot ring, legs with shapes, again in keeping with what you are making. Now I have a whole new shape, unatainable by throwing. Hardly any effort is expended, no kneading of the clay necessary, only soft enough clay to work. Here again the firmness of the clay dictates the pattern left on the reverse side of the clay that was pressed against the mold. One can press the clay onto a piece of lace, crumbs of dry clay of a different color, small extrusions from the hand held extruder, the pattern depending upon how firm the clay is when you start your project. Then when dry, you can apply terra sigilatta or just clean up the unnecessary joins, bisque fire. I then apply a mixture of dark earth materials like copper carb, manganese, or black Mason stains, water, and wash this mix onto the pot to make the pattern stand out. I then wash the surface and you have the pattern showing of the pressed clay shapes. I am into smoke firing my work lately so as not to deal with glazing, but if you are not into this, I then glaze and fire the work to completion. I sometimes embellish the pot with beads or leather strips. Your imagination can really run away here. What a ball.
    I might add that my studio is in the basement two floors below my apartment. That is my exercise for the day going up and down the stairs. I have a TV there and my tiny canine companion follows me wherever I go.
    Thanks so much for the encouraging words. I hope that all of you can follow your dreams to continue to work in clay for as long as possible. My pug mill is holding up fine and I use it to get my clay soft enough as I do throw occasionally using my coil and slab method. My career is spanning about 68 years now. Hope you all enjoy a similar ride.

    • Reader L.

      Wonderful to hear – particularly liked your idea of decorating with beads and leather.

  • Peter S.

    Regarding Merci Weitzen’s (see above) comment concerning pounding and slapping mounds of clay for centering, I agree that one should not use excessive force so as not to damage the motor, but I’ve been using the slapping method to begin centering on my Brent CXC, which I bought when that mode came out, for nearly 30 years now. Today I centered 16 pounds, two pieces of 8 pounds each. I understand that slamming large amounts on the wheel head is damaging, but slapping, at least for me, hasn’t impaired my CXC.

    And, years ago I changed from pedaling with my right foot and now use my left foot. The logic is that since we in this hemisphere throw on the right side of the piece, using our left foot makes us lean ever so slightly toward center and helps to straighten our body a bit.

  • Joan M.

    Bonnie Staffel has a great video covering some of her methods for handling larger amounts of clay. If she still has video stock, I’d strongly recommend that older potters buy a copy–it’s great!

  • David H.

    Bonnie. I did lots of clay work 40 years ago and recently with a new lady anxious to do clay we built a small studio, outfitted it and started in. I have found while I remembered a lot I also needed to learn lots of new techniques. Teaching someone when we are now in our 70’s and perhaps a bid of deficit in attention span was not really easy. So devising new ways is essential. And we now fire with elect, not gas and at lower temps so it is a challenge for me. But to show there are more ways than wheel throwing I directed us in working a lot with slabs. We have made a lot of interesting things this way but still not up where we would like to be with appropriate glazes. So that is our learning focus just not.

    We wanted to party and share with friends so we started something here that incorporates those elements. When we have completed a glaze firing during the few days cooling cycle we have invited friends and organized a party. We start out with me explaining some of the ceramic processes and perhaps doing demonstrations while sharing wine and snacks. Then the big moment we open the kiln where we too look inside for the first time and as I unload I hand pots to friends lined up to carry to tables. Everyone seems to enjoy it and get their first clues to what is involved in this great activity. We also support the Empty Bowl Project for the local homeless shelter event. Great fun and we have a growing list of people who wish to come to our parties.

    Party on. Maybe others may want to do this.

  • Phil S.

    Great job, you are a wealth of knowledge and generous in sharing what you know. Thanks, (Kate)

  • Ceramic Artist P.

    Bonnie, I love the fact that you are brilliant and started making preparation for aging. I too deal with this. I would love for you to make a video or write a book with lots of photos. Please think about it. I want to still be throwing at age 91. Bless you for hanging in there. Please share more with us. Do you have a website or blog. CERAMIC ARTS DAILY please pay attention to her post (comment) as it is on of the most relevant concerns out there today. Thank you Bonnie Staffel…….

  • Meena D.

    Your comments are totally inspirational. I also would love to learn your methods. At the moment, I am a permanently amateur occasional potter since 1975 with major time gaps. I love to learn.

  • Merci W.

    Hi Claire,
    What you recommend in step 3 is madness if you want to preserve your wheel and its electrical mechanisms. This can all be done on a bat at a table away from the wheel. The throwing of a ball of clay onto the wheel is especially damaging to your motor, and any tapping, pounding, or banging is lethal to its long life. Do all this on a bat at a sturdy table or wedging board, rotating as you go. You can use the concentric circles that are on most bats as a rough guide, and do all bashing and squashing before you put the bat on the wheel. Then you can turn it on low and clean up the base of the clay, and proceed with centering. Everything you do in the studio is a habit, so why not form one that will save you a lot of money and grief?

    Merci Weitzen
    Saluda, NC

  • Valarie G.

    When centering large amounts, I have the problem of a hole developing in the middle during the coneing process 🙁
    By the way Go Bonnie !!

  • thank you so much for this post!! i am an ‘older’ potter-want-to-be, tho i totally enjoy playing with my clay and wheel 🙂 this truly was an encouragement to keep on improving and using new techniques to achieve what i ‘think’ i can do. For now, making ‘whimsy’ pottery and selling it at my local farmers’ market is fun and almost profitable… just am working on consistency and growing in the art of it. Thanks again, ivy

  • Ann S.

    I’ve been a full-time potter for about 30 years out of the 45 that I’ve been a clay person. Now, at 75, I’d love to know more about your extruding pug mill and slab method of working! I have a small Bluebird pug mill from the 70’s that still works great. I made some large pots right after I got it, using a thrown slab for the base and extruded coils to form the walls. I had a plate made that extrudes a 1″ cylinder, making nice even coils…….. Bonny, I hope, too, to be working in clay when I’m 91!!!! I can’t imagine life without clay!!!!

  • Andri W.

    Bonnie, you are awesome! I’m a wheelchair user in my sixties and recently tore a ligament in my shoulder from centering a lump of clay. It felt like a fight to the death and I wasn’t prepared to lose. Silly me. I now center wetter clay and let it dry a bit on the wheel before I start. Slower but more respectful as I still want to be playing in mud when I’m in my nineties like you.

  • Bonnie S.

    While most of what this potter suggests is good advice, however I know from having clay as goal for the rest of my life, I had to devise ways to make sure I could continue to work as I aged. At 91 I cannot center a huge amount of clay even as suggested by Claire, and probably couldn’t even at age 80. As soon as I acquired an electric extruding pug mill back in the 70s I started to devise new ways of working that would speed my production as well as eliminate most kneading to prepare my clay. I also learned to throw smaller items off the hump where I only had to center the top third of the ball of clay. In my eighties I started to throw tall big pots with ease using my extruding pug mill and slab method. In three weeks I threw 25 big pots. I was able to do this easily because I had made many pots in previous years using this method but generally under 12″ tall or wide platters 23″ wide without centering a ball of clay. I have been a professional potter for at least 60 years and just this past weekend, gave a workshop about my methods. Aging doesn’t stop aches and pains from misusing one’s muscles and bones that take its toll on the body. I don’t want to quit my profession as long as I can still work. I never knew I would live this long so am so very happy that I prepared myself for this aspect of my life. There is more to throwing than centering a huge ball of clay to achieve one’s goals. Don’t be afraid of changing one’s ways of working as one ages and the body changes.
    I threw lavatory sinks, large punch bowls, sculptures and other pots that require size using my method with ease.

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