Saw the Doctor

I saw my regular doctor today. It was a follow-up appointment for the pneumonia, before we discovered that I had a bronchial cleft cyst. I still can't talk, and I won't find out until Friday what the ENT has to say, based on the biopsy (which hopefully, will verify that it is a bronchial cleft cyst, and not something worse). I have been scheduled for a follow-up x-ray of my chest at the end of April, to check up on something that may or may not be an artifact of the pneumonia, which could lead to another CT scan.

Anyways, my case is the first that my doctor has ever seen in his twenty years of practice. Most cases occur in children, not in forty-some year old adults.

I still can't talk.

I miss singing. I can't sing well, but I miss singing.

I miss doing sound effects. I use them to punctuate my conversations, and all I can do is that horse-lip thing (and whistle).

I miss talking with my wife.

I miss doing funny voices in conversation.

I miss being able to read to Stephanie; full on, read aloud, different voices for each character reading. I used to read to her every night, and she can sight read as a result of it, and is one of the best readers in her grade. The last time I got to read to her was the last Harry Potter book, which I read to her and Julie. I do the Richard Harris version of Dumbledore, a great Snape, but my McGonnagle has too much Monty Python "Mrs. Diesel Engine" in it. I like doing Harry and Ron as well.

Steph has started to read on her own, mostly.

Stanislaw Lem, the Polish science fiction author died last week. I want to read some of the adventures of Trurl and Klapacius from "The Cyberiad" to her (especially the "Cosmic Bard"), but need to be able to do the voices. Reading in a whisper, puctuated by coughs, doesn't cut it.

Visiting the ENTs

I lost my voice last Saturday. I was on day six of the flu, my temperature had just dropped below 102, and I was feeling pretty good. This is before I was diagnosed with pneumonia.

My right eustacian tube felt clogged, and the gland on the same side was a bit puffy. I did the usual stuff; do the 'frog tongue' thing, where you open your mouth wide and stick your toungue out repeatedly (which acts like a pump, to move precious bodily fluids), and ran a pressing finger from the point where the jaw meets the ear around the back of the jaw, then strait down the neck.

Usually works, every time.

The swelling on the side of my neck got worse and worse, until there was a visible bulge. Whenever I swallow, the whole mass moves in an uncomfortable fashion. Finally, this morning, each coughing fit resolved with a gag reflex from the mass pushing the side of my throat.

Julie said it was like I had the mumps, but only on one side. After two days of phone tag with the doctor, I finally pulled the trigger on getting scheduled for a CT scan.

You can't eat or drink for three hours before a CT scan. I took all my meds at 6:30 this morning with a little water, then stopped in preparation for the test. I had a soft tissues CT of my neck.

The test was at noon. I got to take 'contrast' as part of the test. Contrast is an iodine based tracer dye, and is injected into your body during the CT testing to be metabolized by the tissues. The best hint that you might have an adverse reaction to contrast is being allergic to seafood.

You lie down on the bed of the CT scanner, and the nurse puts a needle in your arm. There is a large, mechanical arm, that hovers over the CT machine, and there are fine tubes hooking your arm to its arm. The mechanical arm follows you into and out of the CT machine, as the bed is rolled through the donut shaped mechanism, and it is administering the contrast. When it hit my system, my body felt warmer, and patches of my skin felt wet.

I drove the scans home, and then it was off to a specialist (an Ear, Nose, and Throat guy, not Treebeard). Julie came with, to keep me company. The doctor looked at the films, and he talked with one of his peers. They also ran a camera up my nose to examine my vocal cords, to verify that they were not paralyzed. The doctors are guessing that the lump in my throat is a bronchial duct cyst, which is a congenital defect where a lined pocket of tissue was never reabsorbed properly when I was just an embryo, and has just been waiting for the right kind of infection to fill up. The swelling of the cyst has pushed my larynx off to one side, which is why I can't talk above a whisper.

The doctor performed a biopsy (Julie was very helpful, by suggesting that they go from underneath), changed my antibiotics, and has me scheduled for another appointment in a week.

I'll keep you posted.

Back to the Earth

I have a CT scan today at noon. My voice has not returned yet.

The big bowl was totally dry by the time I tried to trim it yesterday. I kept wetting it down, and trimming it while it was upright on the bat, and I had to leave the splash pans off of the wheel. It was slow, messy going, with mud and water going just about everywhere, and none of my tools being quite right for what I was trying to do.

I ended up knocking the piece off center as I trimmed, and then my elbow caught the rim as it came around. I broke off a piece of the rim about two by five inches.

The remains of the bowl have been moved into an empty clay bag, with all of the trimmings and mud. It took about forty minutes for me to clean all the residual mud off the wheel and floor of the studio, with buckets of water and a sponge.

Julie did a bisque firing last night. I have one bowl in it, a half bag that I threw of the 306. When she was loading the kiln, one of the support chains for the lid snapped, and a screw holding the second chain ripped out. The lid hit the firebox for the raku kiln, which is on top of the raku kiln right now. Nothing further was damaged. I went to Home Despot, and bought some replacement swag chain and screws, and fixed the chains. The new chains are heavier, and hopefully will last another twenty years.

When I feel better, I will start throwing again. We need to pick up a load of cinderblocks for pad for the raku kiln this weekend, so maybe I can work on that.

Pneumonia

Woke up this morning, and got ready for work. I still have a really bad cough, my voice is gone, and the lymph node on the left side of my neck is swollen and painful to touch.

A quick visit to the doctor's office, a chest x-ray , and it turns out that I have pneumonia, and will be out of commission until Thursday. The doctor couldn't hear the pneumonia (probably because I was coughing so hard), which explains why he didn't suspect it on Saturday when I saw him, but the x-ray that was supposed to rule out the pneumonia proved it.

I am on Azithromicyn for the next ten days.

Flu

I've had the flu since Monday. My termperature has been over 100 degrees, and has exceed 102 every day this week. Julie keeps wetting down my pieces, to try to keep them moist, until I can return to the studio.

Throwin' Large

Throwing starts by preparing the wheel. Our studio is a small room, and we keep the wheel pushed up against the wall when not in use. I pull it out a foot or so, and then set up my folding chair.

There are two holes drilled in the wheel head for batt pins. They are little bolts, with round heads, held on by wing nuts from underneath. I install a pair, and then place a masonite batt on by aligning the holes in the batt with the pins.

The two halves of the splash pan are on the counter, by the sink, where they were left to dry after the last cleanup. The larger of the two pieces slides under a fixture that is pierced by the shaft driving the wheel head. The smaller piece clips to it, to complete the circle.

The foot pedal is on the right, off to one side.

The water bucket is half filled with warm water. The wooden ribs get tossed into the bucket, two different sized kidneys, a squared corner with a point, a concave rib with a notch for conditioning the rim, and a small, dense rib that is shaped like a paisley. The smallest kidney sees the most use, followed by that notch in the concave. The paisley rib is the newest, least used and is so dense that it doesn't float. Its a blonde wood, instead of the dark woods of the other ribs. Two natural sponges join the bucket, a flat, thin, triangular sponge (a.k.a. "Sammy Sponge") and a stiffer, fat sponge from the shores of Florida's Gulf coast. I drop in a steel needle tool, as well.

Take out a fresh bag of clay, Standard Clay 266 (Chocolate Brown). Julie endulged me on Saturday, and we bought one hundred and fifty pounds of the stuff. It's an eight inch, plastic wrapped cube, the color of milk chocolate, and weighs twenty five pounds. Peel back the plastic bag, and invert it onto the wheel head. The moist clay smells musty and moldy.

Ah...freshly squeezed.

The cube needs to become a bowl. If I was throwing a mug, I would cut off a piece, form it into a ball, then place it on the wheel.

I have bigger plans.

Some potters slap the clay into shape with the palms of their hands. While effective, in the long term the repeated blows can cause bone spurs to form in your hands. We manipulate the clay against the wheel head to achieve the same results.

Pick up the cube of clay. Rotate it so that one of the corners where two faces of the cube face the wheel head, then 'bounce' the clay off of the wheel. This flattens the corner. Repeat three more times, and we have a piece of clay that has an octagonal cross section, and a more or less flat top and bottom.

The sides have smushed down a bit, past the bottom face of the clay. If we slap it to the wheel head, an air pocket will be trapped, which will cause problems in throwing and trimming. There is this motion that I do with the clay, to push the bottom face back into shape. Think of the final moments of a spinning coin, when the coin is wobbling nearly flat at high speed, where one point on the edge is touching, the touching point circling the center of the coin. This is the motion the clay must take. Pick up the clay, and nutate the lower edge on the wheel head. This bevels the lower edge.

Its now a 'ball'.

Slap the clay down, in approximately the center of the wheel. There is a lot of friction between a hand and the moist clay, so grab a sponge full of water, and squeeze it over the top.

Place the right foot on the pedal. Make sure it is in the off position. Switch on the wheel.

My legs are spread around the splash pan. My left foot should be flat on the ground, but I tend to hook it around the left front leg of the chair. My left upper arm is locked against the side of my ribs, with my left elbow touching the top of my pelvis. My forearm is strait, and the edge of the hand rides the wheel head, and the clay meets the base of my palm.

I apply power, and the clay starts to turn.

Centering the clay requires that the left hand be held still. It bounces against the mishappen clay. My right hand is on top of the clay, near the left, at the seven o'clock position. I stiffen my hands, and lean my body in, and let my weight force the clay to change shape. The trick to centering is to judged the size of the bounces, then slowly reduce their amplitude with your hands, to force the clay to take a new shape.

The bouncing subsides, and smooths out. The base of the side becomes cylidrical. I shift my left hand up a bit, to center higher on the piece, and lock thumbs with my right hand. Leaning in, again, and the piece centers.

I lean back, reducing the forces on the piece, then gently remove my hands. The clay looks like a cake with milk chocolate icing. Rewetting my hands, and assuming the position, I flatten out the cake a bit, by pushing down on the top with my right, while supporting the side of the piece with my left. Shortening the cake increases its diameter. I stop when the cake is about a foot across.

Left hand rides the side of the cake, right hand rides on top. Thumbs are hooked togeather. Using the left hand to steady the right, I place my index finger into the exact center of the rotating cake, and gently push down. A dimple forms, about a half inch deep. My fingertips start to bind with the clay, so I back off pressure, and remove my hands. A sponge is used to put some water into the dimple.

The wheel is slowed down a bit.

Rewetting my hands, I reposition them on the top and side of the cake, and puch downwards into the soft clay with my right fingertips. The clay is soft, I curve my fingers down into the hole to help make it symetrical as it grows deeper. I stop when I get within about an inch of the wheel head. I rewet my hands. Starting from the point on the hole closest to me, run a fingertip strait down to make sure that the hole is perfectly circular, and exactly centered in the cake. If it is uneven, it can be fixed in later steps, but the uneven wall thickness will turn into, at best, an uneven height around the rim, which will be trimmed down. Most pieces have to have the rim trimmed a little, to even it out and make it the same height all the way around.

The wheel is slowed down a bit.

The right fingers are hooked down the center hole, the arm is locked, and I lean back to pull the center hole larger, until it is a few inches in radius. I hold my hand steady for a few revolutions of the wheel, to ensure that the wall is even all the way around.

The wheel is slowed down a bit.

Rewet the hands, then wet two sponges. Grasp a sponge in the palm of each hand, and form loose fists, with the forefinger wrapped over the tip of the thumb. The left hand goes down the center of the piece, forearm straight up, and the right is on the outside of the piece. Both
hands are at four thirty, the second digit of the forefingers facing each other. Gently squeezing the clay between the hands, pull steadily upwards and slightly outwards. The speed of pulling is related to the speed of rotation; a full rotation needs to take place before the hands move more than the thickness of a finger. The distance between the hands is defining the thickness of the walls of the piece. They need to stay thick for now. As the fingers start to bind in the clay, a gentle squeeze on the sponges remoistens the surface. When we approach the top of the wall, we back off pressure a little.

The wheel is slowed down a bit.

The piece recieves several more pulls. Each pull increases the height of the piece. Each pull increases the diameter of the piece. As the piece gets wider, the wheel speed must be reduced so that the clay does not travel through the fingers too fast, or start to bind and stretch. As the bowl starts taking shape, care must be taken to leave sufficient clay in the base of the walls to support the flaring walls above them.

Once an approximate bowl shape is achieved, the wheel is slowed down a bit. The small kidney rib is pulled out, and, held in both hands, its curved surface is used to finish the floor of the bowl. Excess clay is scraped off the rib, into the bucket, as necessary. Shifting the rib to the left hand, and a sponge in the right, the edge of the rib is used to perform a pull on the piece, where the sponge is on the outside in the right hand. This smooths out the inner walls of the bowl.

The outside of the bowl can be conditioned using the concave rib in the right hand on the outside of the bowl, with the left hand gripping a sponge supporting the inside of the bowl. I like to leave the throwing marks, ridges, and lines on the outside of some bowls.

The bowl is slowed down a bit. It turns very slowly now, taking several seconds for a single revolution.

If required, the rim is trimmed with the needle tool. A wet left hand rides the rim, supporting the inside and outside walls. The needle tool is gripped with the right hand, the needle is rested on the left thumb with the tip tangent to the bowl. The needletool is slowly rotated against the thumb through the wall of the piece, until it makes contact with the left pointer finger. Once the clay has detached from the piece (like, it starts to fall off), the scrap is removed by raising both hands simultaneously, high enough to lift the scrap clear of the rim. Throwing nirvana is reached when no trimming is required; the centering, opening, and pulling of the piece all came together to make a perfectly flat rim.

Wetting the notch in the concave rib, I condition the rim of the bowl. Wetting the left hand, I support the walls of the rim with thumb and forefinger. The right hand brings the notch down onto the top of the rim, and the notch is slowly repositioned several times to allow it to round off the rim for the entire circumfrance.

A notched tool is used to cut away a little bit of clay at the base, and a cutting wire is run under the piece.

The finished piece should measuer at least nine inches tall, and at least eighteen inches accross. It would look something like like this:
Nirvana was achieved when throwing this piece; note the lack of rim trimmings to the left of the splash pan next to the water bucket.

This piece was followed by the throwing of four Brooklyn Red mugs, and I trimmed my half-bag bowl thrown from 306.

Two Bags Down, No Big Bowl

I tried another 25 pound bowl.

It started cracking on the inside, while I was finishing the rim.

I cut it back to about twelve pounds.

I'll try again this weekend.

Aftermath

There is a picture, in our flickr photos, of me throwing a rather large bowl.

After the picture was taken, I let the bowl sit on the wheel for a while, to firm up a bit.

If you look closely, the bowl spreads out from the base, then transitions to the vertical.

This was a very bad thing; I didn't leave enough clay in the base to support the walls of the bowl. As I thinned out the walls, and tried to put more shape in the piece, it collapsed.

The shape and size of a thrown piece is proportional to the thickness of the piece, the 'tooth' (kinda stiffness, but not really), the centripedal acceleration due to the rotating wheel, and local gravity (I include the last for completeness, only because I've mused about the shapes I could throw in zero gee, as well as the moon and other planets. The moon would be great for shallow bowls and platters).

A larger piece needs to be thrown at a slower wheel speed than a smaller piece due to centripedal acceleration. Tooth has something to do with it as well, because if your hands aren't wet enough, you'll start peeling off hunks of clay, or stretching the piece.

I ended up cutting the bowl back twice, removing inches of diameter and pounds of clay each time, and trying again, with the same results. I finally made a platter, and have bagged the rest of the clay for recycling.

I grabbed a half bag of clay, and had some success in throwing another large bowl. I trimmed both pieces on Monday night.

Today's Plan

We have a glaze kiln firing to cone 6 today. There are several Floating Blue pieces in there, and we are trying to fire the kiln at a slower rate than the last time. We candled it for a few hours last night, to dry out the pieces, and then I started the firing cycle at eight this morning.

I'm about to drop into the studio to try to throw a large bowl. I haven't thrown an entire bag of clay for a very long time, probably back in the Phoenix studio, so that would be about nine or ten years. We have a lot of boxes of Standard Clay 306, and I am planning to start working through it before I go back to the 266, at least for the large bowls. I'll need to take a few measurements off of the kiln, so I don't throw something too big to fit inside.

Visiting the Standard Clay site for the above link, I noticed that they list the shrinkage for the clay. When a piece is newly thrown and wet, it is larger than a bisqued or fully vitrified piece. For example, Standard's Brooklyn Red clay shinks 12% at cone four, and 13% at cone eight. I was planning on doing some tests (throwing pieces, measuring them, then measuring again after the piece is finished. I have a ray gun that has been sitting in the garage (made from an old candleholder) for a few years, waiting for me to find a nice piece of wood for the grip. Maybe I'll
make a clay grip for it instead.

The Firing Chamber

With the firebox complete, I need to finish the work on the firing chamber of the raku kiln. There are two sets of holes that I need to create.

The hole in the side of the firebox is called a burner port, and is four inches in diameter. It is sized for an MR100 Venturi Burner. I had to compute the volume of the firing chamber and firebox, then, based on the materials and thickness of the walls of the kiln, I could determine the number of BTUs required by the burner, using propane. The kiln was at the top range recommended for the MR750, so I opted for the larger burner. We could always line the kiln and firebox with ceramic fiber to improve the firing qualities of the kiln, but I'll wait until we have used it a bit to make that decision (and hopefully have sold a few pieces).

The first hole in the firing chamber is a vent in the lid of the old Sno Industries kiln we are using. The rule of thumb is that it needs to be at least as big as the burner port in the firebox. If the hole is smaller than the burner port, then it becomes difficult to shove flame into the firebox, due to pressure building up in the kiln.

The second set is a series of holes in the floor of the kiln that we are using. These will allow the flames and gases to rise out of the firebox and into the firing chamber. It seems obvious that the area of these opening need to exceed the area of either the burner port or the vent hole; I want the flow of heat, flames and gases to be controlled by the burner and vent ports, not by the opening connecting the firebox to the firing chamber. I imagine that the bigger the better, and, worst case, I could cut out the entire bottom of the kiln, and just prop up a kiln shelf on stilts or fire bricks.