I've always been interested in how things are made. I once spent a summer working in a box factory making boxes for everything from Guchi #5 to Preparation-H, and since then I've looked at boxes in a different light. I think that it allows you to better appreciate other people's creations when you can map them onto your own experiences. The better you are at playing the guitar the more you appreciate a truly excellent guitarist's work. To me this kind of appreciation is a mandate to dabble in many fields. There's more to it then that though. As you gain knowledge about how things are done in a number of fields, you become better at guessing how things are done in a new field.
It seems like life is full of black boxes, things at we make use of, but don't really understand. I love looking into such boxes. Of course all things are black boxes at some level but you can push that level down a bit. Knowing a bit about mechanical/electronic/software issues allows you a sort of X-Ray vision on many of the more common black boxes in everyday life. For example I may never have seen the insides of some particular vending machine, but by looking at the outside I can guess about the CPU, the coin sorting unit, the motor control, the limit switches, etc. that are in here. As I learn about new fields I improve the scope of my X-Ray vision. Which is what brings me to pottery.
I'm taking a pottery course at a local community center. I'm doing it not only because I enjoy making things with my hands, but also to improve my appreciation of pottery. It's nice to be able to look at a pot, and see how the potter held it during glazing, or see that it was slip cast. It's a way of opening the pottery black box. So enough about why I'm taking the class. Let me tell you about my experiences so far.
Well the first day of class was spent getting out tools, signing wavers, administrivia, getting a demo of centering, and about 10 mins on a wheel before it was time for clean up. For those who are not in the "know", centering the the practice of getting the lump of clay to run smoothly at the center of the wheel. This is important because if your pottery is not centered or has lots of bumps and lumps it will not throw into a circular pot. It's a bit like centering and truing up an irregular piece of stock on the lathe. I think it's important to note that although really good centering can be a little bit tricky you can still throw a decent pot that's a tad out of round. So beginning potters shouldn't be discouraged by people who say things like "It took me two years to learn how to center." They forget to mention that they were still making pots over those two years.
I think I can center quite well now, and I'm sure I owe that in part to my experiences on the lathe. In centering (as with lathe work) rigidity is key. If you have a lump of clay wobbling around, and you push it with your hand two things can happen. If your hand is easier to move, the clay will push your hand in and out, and the clay will stay off center. If your hand is more rigid then the clay the clay will move, and be forced to run concentric to the wheel. In order to get the rigidity needed for centering I dig the elbow of my right hand into the place where my hip bone protrudes, keeping a strait line between my fore arm, and the center of the clay, I push my palm into the clay by leaning forward. If the clay wants to move my arm, it has to push my whole body back. This is a lot harder for the clay to do then just pushing your arm around, and it makes it center quite easily. Don't push with your arm, move your hand by leaning.
It's important to keep your clay well lubricated when you are doing this by occasionally squeezing out a sponge full of water over the piece. As soon as you feel the clay getting sticky again add more water. It's important when the piece is done to remove any water that has collected inside since if you let that stand the pot will dry with cracks in the bottom (very much like the cracks in the mud of a dry creek bed.) Also when you remove your hands from the clay it's very important to ease back with the pressure when you're taking your hands off of the clay. If you remove the pressure quickly the clay can spring back out of true. You want to rather slowly go limp, and remove your hands. If you feel the clay getting dry start ramping down the pressure as soon as possible so that you don't have the clay getting sticky by the time you let go.
In the ten mins we had on the wheel I managed to throw my first pot (18k jpg). It was very short and thick because we hadn't had much instruction on what to do with the clay once it was centered. I was rather surprise to come up with a keeper my first time out. I didn't think I was actually going to make anything, so I had been throwing on the wheel head. (A pottery wheel has a spinning surface that is called the "wheel head" and you frequently stick a wooden disc called a "batt" on it so that when it comes time to remove the piece you simply remove the batt, and you don't have to worry about removing the still very soft piece from the wheel. This is especially important for things like plates which are very stuck down, and would be very hard to peal up off the wheel when wet.) I had thrown this little pot on the wheel head though, so now I had of figure out how to get my first born pot safely off the wheel, and on to a batt for drying.
One of the potters showed my how to run a wire under the pot, and remove it with a minimum of finger marks in the pot. The wire resembles a garotte and is used much like a cheese cutter to slice through clay. You splash a little bit of water onto the wheel, and then pass the taught wire under your pot. The water comes along with the wire, and helps to make the pot cut away cleanly, and not re-stick. Then you put your fingers around the base and lift the pot off onto a near by batt. I was sad that this tends to put some finger dents into the base of the pot, but those can later be removed by trimming, so don't worry about them. After this the pot is draped in plastic, and allowed to dry slowly for next week's class.
I was very excited about this first pot. The whole experience with squeezing the clay, and making this thing with your hands was very compelling. It's right up there with making the first long springy chip in the lathe with a piece of home ground HSS, or pouring molten metal into a mold. I knew when I was doing it that I was hooked! I'm glad that the community center has studio hours, so that I can persue this hobby without having to invest the space needed to have my own wheel and kiln, etc.
Well on the second day I did a little bit more throwing (27k jpg), and my first attempt at trimming. If throwing was a little bit like lathe work, trimming is exactly lathe work. The idea is that your piece has dried enough that it can sit upside down on it's lip without deforming, but not so much that you can't slice clay off of it with your little clay-cutting-metal-hoop-tools. You can give the pot a little squeeze to to make sure it's not too soft. The surface should not be sticky, and a light squeeze up near the rim should not deform it. It should not however be so dry that it's changed color a lot. (We were using a red brown clay, I don't know about color change in other types of clay.) Now comes the task of re-centering the pot on the wheel. The idea is that you put the pot upside down on the wheel head, and use three lumps of clay around the edge to hold it in place as the wheel turns. This is the same operation as centering a piece in the lathe with a three jaw chuck. The way I do it is to stick down the pot about in the center, and then turn it at a slow speed, and use your finger to see where the "high point" of the pot is. (The side of the pot that is furthest from the center of the wheel.) Then I squish down on the lump of soft clay closest to the high spot. This moves the pot towards the center on that side. Much like tightening a jaw of the chuck on a lathe. I do this a few times until the pot is running true.
Now it's time for the trimming. The cutting tool has a wooden handle, and a sharp wire hoop at the end. This hoop is used to scoop clay away from the pot as it turns on the wheel in the same way that a lathe cutting tool cuts the work piece. What are we trying to accomplish? Right now the bottom of the pot is flat. If when it's fired the center sticks up a little the pot will wobble and spin about it's high point. To make a better "foot" for the pot you trim the bottom in at the middle and leave a raised edge around the bottom. This edge sits nicely. Trimming can also be used to:
Remember that the pot is quite delicate at this stage don't pick it up by it's lip, etc. So you use a little wire loop to remove some of the base from the middle out towards the edge, stopping short of the edge. Then use a bigger tool to trim the foot in from the outside, just enough to even out the shape of the pot and remove finger marks, etc. I then smooth over the raised ring that you've formed around the bottom with my fingers so that it doesn't have any sharp edges that would chip later. I also scratched my name into the bottom for good measure.
Well after I'd trimmed the foot we left the pots for next week. During the week they are put into the Kiln and fired enough to drive off all of the water. This is called bisk firing, and I'm not sure what the temp is. When you get the pots back they're much stronger. You don't have to worry about handling them. In fact our studio has shelves of bisk ware all stacked up, and I have had some trouble finding some of my pieces! (Another good reason to put your name on the bottom.) My dark brown pots turned a nice orange/white color, and they shrink which makes them even harder to identify. I think my second pot may still be on that bisk ware shelf somewhere.
Well now all
that is left to do is put glaze on the pots, and have them fired again.
The glazes at the studio are all functional glazes, so you can eat off
of them, microwave them, etc. The first thing to know about glaze is
that you don't want it on your entire pot since the pot would then
stick to the kiln shelf. So you put wax on the foot of your pot so that
if you dip the pot in glaze it won't stick. You can also use this to
put patterns on your pots that will resist the glaze. The wax burns off
during firing. The other thing to know about glazes is that they're
unpredictable. They are a different color after firing, they flow, they
interact in strange ways, different thicknesses of the same glaze can
look very different, etc. So you won't know how your glaze job will
look until the pot is done. It's the most surprising part of the
process, and it's really great to go through the shelves of finished
pots and look for yours not knowing what they'll look like.
If you dip your bisk ware pot into the glaze and then pull it out some glaze will stick and the water in the glaze will be sucked into the pot. So they dry very quickly. (Much like magic shell syrup on an ice cream cone.) You can dip once in one color and then go on to the next fairly rapidly since it dries on so fast. If you have a very thin pot it may stop sucking water and the glaze will not dry as readily. Then it becomes hard to make an even coat. The glaze will have the effect of smoothing the surface of the pot. You can leave some surfaces of the pot un-glazed, but you want to glaze the parts that people are going to come into contact with. (For example the rim of a cup.) That way the cup rim won't be rough and unpleasant on the lips.
Well that's most of my experience so far with the pottery. I haven't yet done any Raku, or even put handles on my pots or anything, but so far so good.
Here's a picture of many of the early pots that I threw. You can click on the various pots to get bigger images of them. My very first pot is the small one on the lower right.
My third pot is that one all the way to the right. It has a nice blue green color. I really like it's size and shape. It fits my hand very well. My fourth(16k jpg) pot (upper left) was glazed by letting some of the glaze from the inside of the pot spill over the brim and around the outside, and then dunking my hand in glaze and grabbing the pot. The fifth (18k jpg) pot (first one in from the upper left) was done by dipping the pot into glaze diagonally, and then turning it around and dipping it into another glaze at the same angle. The three colors are formed because the middle band had both glazes overlapping. I think they came out quite well.
On the night of the ninth class I wanted to try making a tea pot. I thought it would be challenging since it requires throwing a number of pieces that are later joined. The tea pot is made up of three thrown parts: The body, the lid, and the spout. It also has three hand built pieces: A handle for the lid, and two small loops of clay which would serve as attachment points for the tea pots handle. The handle is made of wire and wicker, and its ends thread through these clay loops. The easiest part of the whole things was throwing the body since I'd already had a lot of experience throwing things of that basic shape. The only real difference was that I had to add a small lip at the rim for the lid to sit on.
The next thing I threw was the lid. You throw the lid upside down and make the bottom of the lid have a raised ring that goes down into the tea pot. This keeps the lid from falling off when you tip the pot for poring. This is also where the first bit of trickiness comes in since you need to make the outer diameter of this ring very close to the inner diameter of the pot's opening, and you have to make the diameter of the lid itself have a diameter just slightly smaller then the diameter of the step on top of the pot. So that the lid sits nicely. Potters use a wooden outside caliper to compare the diameters, and this can be ticklish work since the clay is very wet, and easy to ding with the jaw of the calipers. I managed to make a lid that wouldn't fall into the pot, but it was far from snug.
The spout was quite tricky to throw because it was very different from the large diameter things I had been throwing up to that point. I first pulled it up into a tapered cylinder, a bit like a truncated cone. Then I used my two index fingers to narrow the spout into the funnel shape that I needed. It took me three tries to come up with this, but it seemed to work. It's a good thing it doesn't take much clay to make these spouts, or I might have run out of white stoneware. I was somewhat worried about how to get the water out of the bottom of this thing since the opening was so small, but since the bottom of this funnel is going to be cut off anyway it's apparently ok to leave a bit of water in there.
So far so good, but here's where I made my first big mistake. I covered the three pieces, and I put them into the damp box to dry. The next week when I uncovered them I found that the main pot shape was nice and leather hard, but the spout and the lid were very dry. They were a lot smaller then the main piece, so the had dried out a lot more. It was my last day of class though so I decided to try and piece it together anyway. A few dunks in a tub of water softened up the outermost layers, but they were still very dry. I mounted the lid on the wheel, and tried to trim it into a nice lid curve. Leather hard clay trims of in nice curls of clay. My lid trimming was producing dust.
Here you can see
the first handle I pulled. I ended up giving this mug to my friend Tom.
Because if it's size it's not really a mug, perhaps an cappuccino cup.
I was still getting used to how much things shrink.
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