Tuesday, February 23, 2010
Sgraffito Pinch Bowl Part One
One of my readers asked if I'd do a tutorial on how to make this sgraffito bowl. Today I am using red clay so the bowl will eventually be covered with white slip and I'll then use sgraffito to reveal orange stripes. For the bowl above I used red slip over the white stoneware so the stripes are white. Today I'll show how I pinch the bowl into it's final shape. Then in the next post I'll show how I make the slip and carve the sgraffito.
I start out with about 1/2 pound of clay which I cut off a block of soft clay in a 2 x 2 inch square. I hold the block of clay in one hand and I vigorously hit each of the four corners of the block of clay with the palm of my other hand. My aim at this point is to round out all the square edges and to compress the clay into a nice round ball.
Once the clay is shaped and compressed I take the thumb of my left hand and press it into the top of the ball of clay almost to the bottom of the clay making sure I don't press all the way through. Then I start the process of pinching the clay from the inside and outside into the shape of a bowl. I slowly move the clay at the bottom of the bowl up to the top a little at a time, rotating the bowl in a circle as I go - pinch a little up, turn a little, pinch a little up , turn a little and so on.
Since I've become very familiar with this clay I can pinch and rotate quickly and efficiently setting up a rhythm as I go - pinching, turning, pinching, turning. As I'm pinching and turning I'm constantly checking to be sure the walls of the bowl aren't getting too thin. I also smooth all the surfaces of the bowl as I go, both inside and out.
If the bowl becomes too thin or starts to flop I wait a bit for the clay to firm up. If the clay starts to show very thin drying cracks I smooth them over with my finger and if the clay is too dry I dab my finger in some water shake it off and dab just a bit of moisture on the clay to cover the crack, rubbing the moistened clay to smooth over the fine cracks as I go.
Once the bowl is formed in an upright position I smooth the inside and outside of the bowl and feel with my fingers to be sure the walls of the bowl are the same thickness.
At this point the clay becomes really soft and shows finger prints easily. To work on the underside of the bowl, I use a dry sponge and balance the bowl on a jar. I also make use of the dry sponge to support the opposite side of the bowl I am pinching.
After I smooth all the surfaces, and while the bowl is still quite pliable, I immediately start to bend the rim of the bowl over a little at a time. At this point I am gently coaxing the clay into a different position, being careful not to stretch the clay too far all at once and tear it.
All the while I'm keeping a close eye on the surface of the clay to be sure it doesn't stretch too thin or develop any fine cracks, checking the front and back of the bowl regularly. My goal is to bend the rim of the bowl almost completely over to the depth of the inside of the bowl. Once I am satisfied at the shape of the bowl I set it aside to dry. The first couple of days the bowl is drying I keep it lightly covered with plastic and I move it so the bottom doesn't stay wet. I also check to be sure the edges are not getting too dry.
Stay tuned next time for Part Two of how I make the slip, apply it to the bowl and carve the sgraffito into the bowl. Comments and suggestions are welcome.