How to Throw a Pot
First, you have to realize I am talking about clay… not marijuana. Second, you have to have access to clay and a kiln, there are stores out that that will fire your clay for a fee. These stores are ok, but if you have a lot of work, buying your own small one is cheaper. My school fires to "Cone Five". What that means, is the little cone indicators that tell temperature melt at the fifth cone (*note, cones go up to 10 realistically; but 5 is about 1600ºf). So this isn't something you can really do in your kitchen oven.
The right clay is the first important decision you have to make when throwing since you want a good elasticity, and you don't want anything that is sharp as it will tear up your hands. Either buying pre-made clay, or going to a school that makes their own clay is a good idea.
Wedging is the process of working all the air out of a hunk of clay, since air bubbles can throw off the balance of your work, and can also explode in the kiln which will destroy your work. Since trapped air is so detrimental it is important to work as much of it out of your clay as possible. Wedging is sort of like kneading bread, but since clay is harder than bread, it involves a lot of slamming it into the table. If you do not have the arm strength to smash the clay into the table with the heels of your palms, you can always just smash balls of clay into the table by throwing (literally) the clay against the table. This doesn’t work as well, but takes less arm strength. It is good to wedge a really big piece of clay at once, since usually you will want to cut it in half to make sure there are no air bubbles in the middle (since you can see them when you cut the clay open, and they will appear as pock marks in the clay).
Wheels and Setting Up
Wheels are fairly important too, the one I am using in class is automatic, and operated with a pedal; not unlike a car. There are also wheels that are not motorized but rather set in motion by the operator; they require kicking, and are more akin to manual cars.
Kick wheels have their advantages, and disadvantages. Some of the advantages are that you get more intimate contact with your clay since you are forced to keep the wheel moving more and slower. Some of the disadvantages are that you have to keep the wheel moving, you cannot get the wheel to some of the faster speeds, you have to coordinate your hands and feet, and that it is much harder to get up from the wheel and keep your momentum.
The wheels that I am using in class have shields on them. This keeps the wheel cleaner, and the thrower cleaner too. The main idea with throwing is using centrifugal force to pull the clay out, and the faster you go the faster the slime that you will be creating flies off the wheel. Make sure you put the guard on the wheel tightly, this will collect all the extra slime and water that spins off your masterpiece. Kick wheels don’t have shields, but they have larger tables that keep the thrower clean. Kick wheels require less water because you aren't moving as fast, and don’t create as much friction.
So assumedly at this point you have a wheel (be it kick or automatic), a guard for your wheel, and a chair. You will also need a towel (beach towels are the best since they are big and absorb a lot), a bucket of warm water, and assorted clay tools (among these you will at least need a pin tool, a wire string, a thing with a point that makes good beveled edges, and a sponge).
Centering is the first major step in actually throwing. This is the step that makes everything else possible, since if the clay is off center, the motions made will not be equal and balanced which will throw off the even form of the clay, and even smooth flowing clay is what throwing is really known for.
Your wheel has a guard around the plate, it kind of looks like a turn table with a plastic guard around it. To center your clay, you take your square of wedged clay, and wet the bottom; on the plate of your wheel. Placing it on the wheel is kind of a misnomer, you really want to slam it into the wheel since you don’t want air between the metal plate and the clay, the water helps make the seal. Once the clay is stuck to the wheel, you shouldn’t move it because that will break the seal, the only way to center it now are the centering techniques that I will outline.
How exactly to center:
First, you have to be sitting correctly, since centering takes a lot of upper body strength that most people don't have, there is a way that you can sit that will use pressure from your thighs to help move the clay. Sit on a stool that makes you about level with your work. You sit with the plate in between your legs, and most people seem to think you work with your arms free (your elbows unanchored) but this is rather foolish because the clay will be a lot stronger than you are. What you want to do is anchor your elbows into your thighs, and squeeze with your thighs into the clay. This will give you a firmer grip on your clay. The clay really needs to know who is boss at this moment, because when it is spinning and you aren't anchored solidly it will cause your body to rock. You cannot have that because you will never get your clay centered if you let it move you instead of vice versa. Once you have your clay anchored, and your body anchored let out a nice growl, seriously, you need to intimidate the clay. You are ready; what you need to do is wet your hands slightly, and start the clay spinning. NEVER touch the clay unless the wheel is spinning.. So with the wheel going, with wet hands apply pressure to the clay to form it into a ball shape. Smooth out the bumps, and round it out; it might help to squeeze the base and form a tower, and then smash it back down with your palm. When you are done, the clay should sit in the center of the wheel and have a nice smooth consistency. It should also be ball like in shape, and try not to use too much water. Adding water to your clay is also a double-edged sword in that it makes the clay less sticky, but is also weakens it allowing it to become goo faster.
Once you have your clay centered you can make anything you want, the easiest thing will probably be a bowl in that the clay will fight to spin out. You should probably start with making cylinders first though because this is an important concept. To make a cylinder, take a 3-4 pound ball of clay and center it, once centered you can open the ball up. Once you open your ball of clay it cannot be fixed, so be careful. Once you have the outside to a nice feel, use your left hand (if you are right handed) to open it by using your first finger and middle finger to create a hole in the very center. It is important to support the wall of the ball as you open it up, because the walls will collapse if you don’t. So with your right hand, support the walls, with your left create a hole that goes down almost to the bottom (you really don’t want to go all the way through or else it wouldn’t be a bowl), once you are far enough down, scrape out the bottom, and smooth it out with your finger. Once the floor is made you can create the walls and make the cylinder as tall as you want. To bring the clay up and make the walls taller press on the clay with your hands on either side. Make sure to steady your left hand with your right, press with your fingers softly together and pull slowly up. This should draw the clay upward, but it will most likely start to flare out. To keep this from happening, remove your left hand and cup the clay inward. Try continuing this method until you have something which pleases you. If you knock the clay off center, do not try to continue since there is no way to re-center it once it is opened, and you cannot make it even if it is off center.
Once you have something you like, and would like to keep, the important thing is removing it without ruining it. This is where your sharp tool, wire string, and sponge will come in handy. You need to bevel the edge of the pot with your tool (a finger will work too), this will make it easier to remove. While the wheel is spinning, take your wire string, and hold it against the plate. Quickly and evenly bring it toward you and this should evenly cut the clay from the wheel. Then take your sponge and fill it with water, and squeeze it onto the plate to "float" the pot. Do not try to pick up the clay piece while it is still wet. What you can do instead is use a spatula or clay pot removers to pick up the pot from the wheel. Place the pot on a Flat wooden board, this will help it dry evenly.
Once your clay is dry, really completely dry to the point that it is warm to your touch it is ready to be fired. After it is bisqued you can glaze it and then high fire it.
How Clay is Formed:
Clay is caused by movement of ice, and organic acids.
Three Major Properties:
- Deforms without cracking
- Remove force and the shape you applied to it remains
- Strong when dry
Clay Body- a mix of clays and secondary materials
which make up a particular blend to a vitieons state.
Clays that might go into a body
- Kaolin- white, shrinks really bad, and requires high fire to set it.
- Ball Clay- plastic, grainy, grayish, flexible, and high shrinkage.
- Stoneware- large firing range (sets at high and low temperatures),
plastic, grey or tan – very nice clay.
- Fireclay- mountain/desert clay, high temp range, strong, grainy,
won’t crack if you dramatically
change the temp quickly.
- Earthenware- high in iron (and therefore very red), kind of plastic,
very porous (it leaks).
- Raku- stoneware, needs to be shocked.
- Bentonite- gummy, like cat litter, expands, gives plastic, but cannot
be used alone. (only up to 10%).
- Plasticity- ease in which clay can be formed without
- leather-hard- can scratch it, carve it, but you CANNOT
- green-ware- can still be reclaimed, but is completely hard.
- reclaimed- add water to dry clay to be mixed in a new batch.
- bone dry- very fragile state before firing.
- bisque- after fire, before glaze. Cannot be reclaimed.
- vitreous- much more like strong glass.
- difference between it and bisque is heat.
- slip- clay glue, - you can also use it to color your clay.
- flux- iron, lead, etc. causes pretty colors.