Friday, July 9, 2010

My Process: Ceramic Clays, Stains & Tools

Note: if you've never worked with high-fire clays before, i recommend you look up a local ceramic supply store or school that offers classes in your area; this little tutorial is only meant for people interested in how my figures are made, and for those with some experience with ceramic sculpture and firing processes. If you're under 18 years of age and you're reading this, please talk to your parent or guardian before attempting to fire a kiln.
Any kind of ceramic clays will work; i prefer mid- to high-fire ranges (cone 05 to cone 6). My favorite source in TN is Midsouth Ceramic Supply, located in Nashville. My favorite source in NYC is New York Central Art Supply, in Manhattan (their range of ceramic clays is somewhat limited but they get extra points for comprehensiveness: their second floor full of exotic papers is my idea of heaven, but i digress). Shown here is a buff colored high-fire stoneware, at what i consider an ideal working state: in a room that's 72 degrees Fahrenheit, and 72% humidity. The drier and hotter the room is, the faster your clay dries out. The cooler and damper the room, the longer your clay's 'open time,' or time you can work it.
Shown here are an array of my favorite tools (from left to right): two small wooden knives (the first one i've had since i was about ten years old; you can see where i've had to whittle it sharp again), a red-handled stylus from the days when graphic design involved using sheets of transfer type; an empty mechanical pencil used to impress tiny circles, usually for the pupils of my Humpty Dumpties' eyes; two salvaged dental tools (get friendly with your dentist!); a standard ceramic 'scoring' needle used to 'score and slip' two pieces together; a handmade scoop utilizing a paper clip and a straight pin at opposite ends; a bamboo calligraphy pen; and a spare red-handled pattern-transfer wheel from my sewing basket, so the red-handled stylus wouldn't feel lonely.
Pure pigment, high-fire ceramic stains are expensive, but a little goes a long way. I'm still using the first tiny bags and jars that i bought 20 years ago for the most part: I keep a palette of dry stains in an old "Jelly Bellies" assortment box for easy access, and dry mix them as needed (except for copper carbonate, cobalt carbonate, and rutile, which alter chemically when mixed with other colors; everything else is pretty much 'what you see is what you get.' Pinks fade a bit with no overglaze while yellows and blues can deepen in high-fire, depending on what they're on or under, clay- and glaze-wise.
You can also buy pan sets of underglazes, which are mostly just ceramic stains suspended in gum arabic so they stay put on the greenware. Mine have been emptied and refilled with ceramic stains and filtered water so many times i've lost count. These basic eight colors here cover just about all my organic mammal needs, color-wise. Old pudding cups, sour cream containers, and baby food jars pinch-hit as pans for alternate colors. An assortment of decent brushes help with mixing and application, and a small pot of 'slip' (slurry of water plus whatever clay i'm sculpting with, if it's white) helps when i'm creating lighter tints of some colors.
Chunks of clay are sliced using a length of florist's wire anchored to a table-clamp (i think this one's actually a lamp-base, but whatever you have handy works). It helps to keep them an even thickness, but if you're a bit wobbly like i was here, no worries. You can even it out in a couple of different ways. Slices for a bust or cone that's about 5" high needs to start off about 3/4"to 1/2" thick (1 cm).
While the clay is still quite moist, you'll need to thin it down by about half, either by wedging it thin on a canvas-covered board (see diagram in the next post), or if they're relatively small, you can just hand-pinch them down. As with wedging, compressing the clay strengthens it, & drives out any air bubbles. Most clay that you can buy in stores has been run through a pug mill to de-air it, but when you're working on something that's going to take weeks or months to finish, you can't be too careful: one little air bubble in a piece and it'll explode in the kiln.
Once the slices have been pinched or wedged into slabs, i tear them into triangles, curling each triangle into a cone. For a narrow cone, i let the corner opposite the longest side be the point of the cone. For a medium-width cone, i pinch a fold into the middle of the longest side, and let that be the point of the cone. For a wide, saucer-like cone, i tear the slab into a circle and cut out a tiny wedge-shaped slice (like removing a skinny slice from a pizza, and the center of the circle becomes the point of the cone). I then 'score-and-slip' the two edges of the cone together.
Shown here are a few rough cones, before any refining was done.
None of these cones is more than four inches (10 cm) from base to tip. If you wanted to work bigger than this, i recommend thinning your slices by throwing them out on a wedging board, rather than pinching. (See next post). These cones became the busts of the various animals in the photos below. The narrowest cones became birds, some fish, and some mammals (such as a borzoi hound's head, and a deer's head). The medium-width cones became various mammal's heads for the most part (rabbits, some dogs, and a pony), while the wide, shallow cones became the faces of stouter faces, such as bears, owls, and cats.

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