Tuesday, July 6, 2010
Rolling a Slab
You don't need many tools, much room, or a slab roller to make a slab built piece in clay. Here's how I roll a slab to make a slab for a vase. I do have a slab roller a friend of mind made me, but it is trapped behind pallets of tile.
I start off by cutting a generous half inch of clay from a fresh block of clay. I put the block of clay on my smooth sided Masonite board. Be sure and click on the link for Masonite board, I learned a lot about this environmentally friendly material. I have cleaned the Masonite board with a sponge beforehand. I don't want any loose particles of dry clay to contaminate my fresh slab of clay.
If I use very plastic clay or porcelain clay I might roll the slab on a cloth to flip it over easier without making an impression in the clay with my fingers. Most of the clay I am using now I can roll out directly on the board and it doesn't stick.
After I cut the section of clay I lightly wipe the block of clay on all its sides with a sponge to remove any dry particles of clay from the surface. I don't want it too wet but I don't want dry clay in the slab. Each time I use the sponge I rinse it out in my bucket of water and squeeze it well.
The most important part of getting a good slab of clay is rolling the clay in every direction. I roll the clay lightly and flip the slab over one quarter turn, roll again, and flip, roll again and flip. If I flip clockwise, I switch halfway through and flip counterclockwise.
I'm using a plastic rolling pin, it's easier to clean and clay doesn't get embedded clay in the surface like a wood rolling pin does. I check the rolling pin often to be sure no clay burrs are sticking to the surface. If they do I sponge the rolling pin off and wipe it dry before rolling the slab any more. I let the rolling pin do the work and take my time getting to the slab thickness I want. Sometimes the edges of the clay slab get thinner, but I cut those off anyway so it doesn't matter to me.
While I'm rolling the slab of clay, if I see surface cracks developing I might lightly wipe with a damp sponge to keep the clay moist. After I roll out the slab I lightly wipe the edges of the slab with a sponge to keep the edges from drying out too much.
After I apply the slip in the pattern I want, I cut off the edges to square up the clay and then I use the slab for the piece I want to make. For this slab I made a vase. I stood up the vase by wrapping the slab around a paint roller. A roller has just enough shape and yet it is soft which makes it easier for me to stand the clay slab up while I score the ends add the bottom for the vase. For photos of the paint roller in a vase and more slab photos, please see this other post of mine, Reverse Design. Comments and questions are welcome.