Wednesday, August 17, 2005

Dry Trimmings: Throwing Log #3

I trimmed my vase last night.

The piece was beyond leather hard. It was cold to the touch, so it still had some moisture in it , but it was too dry. The walls at the base were absurdly thick, and there was an asymetric bulge about half way up the side. The piece was pulled out of circular when I removed it from the wheel

I probably should have tossed it, but I need the practice.

I centered it on the wheel. You put the piece, inverted, onto the wheel head, decide which part of the wall is most circular, and then try to line the piece up with the axis of rotation so that there is no perceptable wobble when the piece rotates. I brace my arms agaist the splash pan, hold out a finger until it barely touches the piece, and slowly rotate the wheel. The piece rotates, and you find the place that is pushed out the most off center (POMOC). Opposite of that point, is the place where the the piece is pushed in most off center (PIMOC). Observing the distance between the tip of my finger and PIMOC, I stop the wheel at POMOC, and push the piece towards the center of rotation half the observed distance.

Sounds complicated, but it only takes a few seconds. I can suceessfully pop a partially trimmed piece off of the wheel, check the current thickness of the walls, then recenter and continue.

I ended up using a steel rib to shave off most of the excess clay. The rib needs to be bowed to keep it from chattering on the piece, and my fingers are really sore this morning. I'm thinking of wrapping a bit of wire around the rib for next time.

The clay peeled off the pot in little chunky shavings. I'm working with Stardard Clay's 266, so the shavings look like milk chocolate that has been run through a rotary grater (from my trufflin' days). I saved them all in a ziplock bag, in case I need to make slip.

The piece is a pleasing shape. Its on the drying rack.
Over the weekend, we went down to Daley's Ceramics in Vineland, and bought some clay. We picked up a hundred pounds of raku clay, fifty pounds of 266, a box of pyrometric cones for our kiln sitter (cone 6), and a new trimming tool.

Joe is starting to mine his own clay, and says that it fires to an ivory yellow at cone six. Julie and I plan to pick some up, to give it a try. Joe wants to know how it does in a raku kiln.

Thursday, August 11, 2005

Ambition: Throwing Log #2

I got ambitious tonight.

I've been drawing pictures in the margins of my notebooks at work of pottery. Whenever I am in a meeting, and there is a little downtime, I'll start doodling.

There was a pot that I made back in Atlanta, called "Love Potion #9". Every quarter, Vicki would assign a project, and her students would work during the sessions on their pieces. We would bring them to an end-of-quarter pot luck dinner, and talk about them. One quarter, we were given the assignment to choose a song, and make a pot to go with it.

The piece was a lidded jar. It ballooned out from a narrow base, curved back in, and then I had thrown an inverted lid with a knob on it. The whole piece was carved in a quilted pattern, along with parts of the lid. Since the piece was thrown out of Standard Clay Company's 266, the unglazed parts were a dark, chocolate brown, and the only two glazes that I liked on the piece were Floating Blue and a lead based transparent (I think Chun transparent, but I'd have to check my notes). Floating blue won out.

The piece sold in a gallery, but I still have pictures of it.

My doodle at work is a pot much like "Love Potion #9", but a raku piece. I want to glaze it with Seth's Luster ("the raku glaze of ill repute"), but only glaze alternate diamonds of the quilting in a harlequin effect. The rim of the pot I want to carve into a rope pattern, and the lid will have, along with the same quilting, three tapered spindles of clay, drooping like a jester's hat, with jaunty bells hanging from them.

Anyways, after I finished baking a blueberry tart after dinner, and changed into some work clothes, I pulled my photo album out of the library, and took my finished picture of "Love Potion #9" out. It was the first jar that I threw in that shape, and was the only one that had dimensions that "worked" in my mind. I went to the studio (leaving my sandles outside, so I don't leave muddy footprints all over the house when I finish), broke out my tools, set up the wheel, and started to throw.

I don't use a lot of tools to throw with. I have four wooden ribs (one small kidney which is my favorite, one large kidney for big bowls, one concave rib for controlling outside curves {with a rim notch}, and one pointed rib with a right angle on it), a needle tool, a flat natural sponge, and two fat chunks of natural sponge. I have a bucket that is about six inches tall by fifteen wide full of water. There is also a cutting wire for the clay, and to cut finished pieces off of the wheel.

I have to focus on centering. I can get away with a lumpy polygon of clay to start with, and I forget whether to lock thumbs of my two hands or not (I think I'm favoring no thumb lock at this time). Opening the piece is not a problem, I had to develop a technique to allow my a sloppy initial opening when I worked on large bowls, so I tend to run a wet thumb along the inside wall from top to bottom after I open to make the opening perfectly circular and centered.
Raising the walls is the skill that I need to practice. The inside hand needs to be slightly above the outside hand, everything needs to be properly wet, and both hands have to work together. I'm just a little out of practice on the long pulls to raise the walls, and throwing two mugs wasn't enough to regain my technique.


The harlequin piece is a little bit beyond my current skill level. The walls were too thin at the top when I had finished raising them, so they would not support the kind of lip that I wanted for the lid. There just wasn't enough clay to even make a lid lip with, unless I lopped off a few inches.

I moved the piece to the damp box, cleaned up, and then worked at wetting down the dried out clays again. I'll trim the piece tomorrow, to get back into practice, then go back to my plan of throwing some tall vases to carve. I'll come back to the lidded jars in a few weeks when my skills come back.

I need to find my purple ceramics sketchbook, and start bringing it to work with me, so I can transcribe my pictures at lunch or after work.

Tuesday, August 09, 2005

Pulling Handles

I spent a couple of hours in the studio last night. I couldn't find our extruder, which is like a big caulking gun with a brass barrel. I remember Julie buying one from Daily's Ceramics over in Vineland, but I couldn't find it in the studio or garage. I had to 'pull' handles for my mugs instead.

Take a small piece of clay. squeeze it a bit to make it approximate a fat, lumpy handle. Standing over the sink, get one hand dripping wet. Pinching one end of the clay with your dry hand, and allowing the clay to dangle down, run your wet hand along the length of the piece, squeezing gently. Its sort of a gentle milking motion. The handle starts to thin out, and take on a (more or less) uniform cross section. It tapers the farther you get from the dry hand. When it is sufficiently long and thin, stick the top end upside-down onto a board, and drape the rest of the handle in an arc that goes off to one side. The handle takes on a shape like half of a heart, laying on its side.

Repeat as necessary.

The trimming went fine. I usually put each pot down on the wheelhead, and lay my hand next to it, then judge the difference in height between by hand and the floor of the pot. This gives me an idea of how much clay needs to come off.

When I finished the first mug, and took it off the wheel, the base of the pot was too thick. I could run my fingers simultaneously along the inside and outside walls of the pot, and feel that the wall got thicker as I approached the base. I had to put the piece back on the wheel, and trim more off the bottom. In doing so, the foot of the piece became too tall, so I had to trim that down a bit too.

The second mug trimmed no problem.

Putting the handles on was a little more messy than I liked. I'm used to putting on extruded handles, which have a uniform cross section. Pulled handles have a changing taper, so I had to fuss with my needle tool and an Exacto knife to get the cuts on the two ends of the handle right so that they left the pot at a pleasing angle, and joined to make a pleasing curve. They are a little heavy for the look of the mugs, but I know my technique will improve.

I got out of the studio about midnight. I spent a lot of time looking for the extruder, and I took my time with the trimming of the mugs to get them right.

Tonight I plan to work on a vase or two.

Monday, August 08, 2005

Dream Machine

I'm about to change, and go into the studio to make handles and trim my coffee mugs.

At lunch today, I ran across an interesting web site. I've always wanted to make a machine or gizmo out of clay. I've wanted to for years, but, other than making a clay pinhole camera (with a brass shim pinhole), I've never come up with a workable idea.

Today, I found this, a UK site with plans for clocks with wooden gears and works:

Julie says that anything rolled out on our slab roller will stay flat, as long as it isn't stretched when the slab is moved. I could make a 'cookie cutter' out of scrap metal to make the right tooth shape for each kind of gear, then use it to cut out each individual tooth. The quadrant cutouts for each gear could be made with an exacto blade, or another cookie cutter.

It might require a low shrinkage clay as well.

Sunday, August 07, 2005

Throwing Log 1

Went into the studio this morning, and threw for the first time in a few years.

Standard Clay Company 266 (Dark Brown).

Its odd to get back into it. There is a lot that I had forgotten, and many things came back as I went along. I had a little trouble centering, but fussed with the clay a bit, and adjusted my stance, and was successful. I worked with 'small' lumps of clay, about the size of a tennis ball. I need to get a pair of bifocals, or start to throw without my glasses on, since I couldn't see the pieces when I was up real close (like my nose being an inch or two away, as I used the point of a rib to put a grove around the first piece about three quarters of an inch below the lip. I had to go by feel.)

Back in the day, I would throw an entire twenty-five pound bag at a time, into big mixing bowls. After a brief chat with Julie, we decided that that was not where we wanted to go right now. While large mixing bowls are impressive, they take up a lot of space, and I think that we have three or four in storage right now.

I threw two large mugs. They are in the damp box, drying out, and hopefully I can trim them tomorrow evening. As my technique returns, I should be able to throw them with less clay and less waste, but I want a nice mug to replace the one I used for years at work, and I somehow misplaced it when visiting another building. Two mugs doesn't sound like much, but I'll need some down time to think about my technique, and to decide what I want to make.

I spent some more time cleaning the studio, sweeping the floor, and then hand mopping it with sponges. I went through the bags of clay again, and rewet all of the Great Lakes Clay Company clays. The song porcelain and raku clays probably need to be wet down daily for the next week or so before I can use them again.

I know that I want to make my raku rockets. I also want to work on tall, vases, with carving on the shoulders similar to the shape of a turbine. I'll raku those as well. I have my trout template waiting for the slab roller, once I finish reconstituting my raku clay. Julie is asking me to make some functional pieces as well; like the angel food cake pan that we picked up in Seagrove on vacation. I want to focus on the raku, since I think it makes better gifts, and I could sell it for more in a gallery, similar to the pieces that I sold in Atlanta.

Wednesday, August 03, 2005

Clay Recovery

We spent the weekend in the garage, doing some cleanup and reorganization. The slab roller that I built Julie three summers ago is now in a usable spot, and we have a work table next to it. We also cleared off a series of shelves for greenware and bisqueware.

This evening, I went into the studio, and worked on recovering some of the dried out clay. I unwrapped two hundred pounds, wet it down, then rewrapped and sealed the bags. This adds moisture to each bag, and resealing them allows the moisture to even out.

The porcelain was in the worst shape (after I threw out the Rod's Bod; the box seemed to have two different kinds of clay, and both were pretty badly dried out. I tossed them, since I have no idea which cone either of the bags should be fired to, since neither of them could be Rod's Bod).

The 266 was in the best shape. It was just a little on the firm side. I'll check it tomorrow after work.