How to 'Throw off the Mound' in Pottery

  • 01 of 07

    Center the Clay

    Center the clay at the top of the mound for throwing off the mound on the potter's wheel.
    Janet L. Giles

    Throwing off the mound (or throwing off the hump as it is sometimes called) allows potters to make quantities of small pots or bowls very quickly. It is a technique that many production potters master and use as a matter of course.

    When getting ready to throw off the mound, make sure to include placing a ware board next to the wheel so you can easily place the pots on it as they are completed.

    You will want a fairly large quantity of clay. Wedge the clay into one lump, usually using between ten and twenty pounds. Once ready, the clay is smacked onto the wheel head and slapped into an approximation of centered while the wheel slowly rotates.

    The entire mound is not centered all at once. There is no need, as each section will be centered separately, and centering the entire mass is an unnecessary strain on the wrists and arms.

    Only the upper portion of the mound will be worked at one time. After lubricating the clay, the upper area is shaped into a tallish cone and roughly centered. The very top of the cone needs to be completely centered.

    Continue to 2 of 7 below.
  • 02 of 07

    Open the Clay

    Open the clay while throwing off the mound on the potter's wheel.
    Janet L. Giles

    Before opening the clay, it is a good idea to create a groove defining the area you will be working with. You want a mass of clay about the same size as a baseball, or about one pound of clay.

    Work with the wheel at half or three-quarter speed, keeping the clay well lubricated. Open down to within about a half-inch of the groove. This extra clay is needed since most pots thrown off the mound are often trimmed to have a footed base. (This is done when the pot is leather hard.)

    Create the floor to the width of the pot you desire. Bowls should have curved floors that flow into the walls, and other pots should have flat floors that meet the walls at a well-defined angle.

    Run your fingers over the floor several times, without moving clay aside into the walls. This will compress the clay and reduce the possibility of S-cracks.

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  • 03 of 07

    Throwing the Walls

    Throwing a pot off the mound, showing the ridge created during the actual throw.
    Janet L. Giles

    Throwing the pot's wall is done the same way as if you were working directly on the bat. Work with the wheel at slow to very slow speed, keeping the clay you are working with well lubricated.

    Be sure to begin the throw with your right hand positioned below your left, with your left hand beginning at the very base of the pot's wall where it meets the floor. Compress the rim and remove excess liquid after every throw.

    Remember to keep the walls as even as possible from base to rim; however, do take into account any shaping you will be doing as you trim the pot when it is leather hard. Because you are working with a small amount of clay, you may only need to throw twice, or perhaps even only once, instead of the more usual three times.

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  • 04 of 07

    Finish the Pot's Form

    Finish the pot's form while throwing off the mound, before the pot is cut off.
    Janet L. Giles

    Finish the pot as you throw off the mound just as you would finalize the thrown form on the bat. Stretch, flare, collar in, and smooth the shape as desired.

    Make certain to remove excess liquid from the pot's floor, and compress the floor one last time. Compress the rim for the last time as well.

    Continue to 5 of 7 below.
  • 05 of 07

    Wheel Trim the Pot

    Wheel trim the pot while throwing off the mound, before cutting it off.
    Janet L. Giles

    When throwing off the mound, do a preliminary trim of the pot while it is still on the mound. You will almost certainly be doing further trimming once the pot is leather hard, but removing as much of the excess now makes further trimming easier.

    In addition, you will want to sharpen the definition of the groove defining the bottom of the pot. This will make cutting it off easier.

    Continue to 6 of 7 below.
  • 06 of 07

    Cut the Pot

    Cut the pot off after throwing on the mound.
    Janet L. Giles

    Make sure your groove at the base of the pot is still well-defined. When cutting pots off the mound, use a very flexible line that won't kink the way wires will.

    I prefer fishing line that is at least 30-pound test, with a preference toward the braided line as opposed to a monofilament line. By tying an old sewing machine bobbin at one end, I make it easier to keep the line from getting lost among the scrap clay.

    As the wheel very slowly rotates, lay the line into the groove, being sure to keep the line parallel to the bat below. Once the line has been laid all the way around the pot, pull the ends in opposite directions so as to cut through the clay.

    Continue to 7 of 7 below.
  • 07 of 07

    Remove the Pot and Continue to Throw off the Mound

    Once it is finished and cut off, remove the pot and continue throwing off the mound.
    Janet L. Giles

    Once it is finished and cut off, remove the pot by carefully lifting it free of the mound, using both hands and an even motion. Set it on the ware board that you have ready beside you.

    Some pot deformation is usual, especially if you are lifting the pot with your hands. If you are doing a lot of work off the mound, you may want to look into getting pot lifting tools, or pot lifters. Check with your favorite ceramic supplier to see if they carry them.

    After the pot has been removed and is safely set aside, center the new upper portion of the mound and begin the process again. With experience, many potters can throw a series of pots in which each pot only takes one to two minutes from centering to ware board.