How to Throw a Large Bowl on a Pottery Wheel

How to Throw a Large Bowl on a Pottery Wheel
A large clay bowl glazed with two tone engobe
Typically the larger an item made on a potter's wheel the more difficult to make. Greater mass spinning equals greater momentum. This greater momentum of an object is often too much for the weak unfired clay to take and stay coherent. That's why there is a need for a guide that deals specifically with large items thrown on a potter's wheel. In this guide we will use a simple bowl, but the principle for most objects is still the same.

Things You’ll Need:
Potter's wheel

A lot of clay

Damp sponge

Throwing a Large Bowl
Step 1:
To throw a bowl or a plate, you do not need to form a cylinder. Center the clay and open it as usual. Then, instead of bringing the wall straight up, make a bowl shape by widening the opening and bringing the walls up and outward at the same time. With most large objects, the clay should be brought outward or upward, but it is very difficult to do both as it puts too much clay away from the pieces center of balance.

Step 2:
Use the heel of your right hand to enlarge the opening and force the wall outward. Your left hand supports the clay on the outside, fingers keeping the clay from bulging out at weak points or losing their symmetry.

Step 3:
Slowly bring up the wall outward by gripping the clay with the tips of your fingers, one hand on the interior and the other on the outside, and lifting upward.

Step 4:
When the wall is at the desired height and distance from the center, it is now time to thin and smooth the interior of the bowl. With the wheel moving at normal speed, place the tip of your thumb to the very center of the bowl and lighting draw it to the lip of the bowl. To keep the bowl from growing trace your thumb from the lip back to the center. This will help to evenly distribute the clay of the bowl and avoid thick or thin spots.

Step 5:
In order to shape the base or foot hold your right hand just about the rotating surface of the wheel and press it inward to the outside base of the bowl. The middle finger should skim against the surface of the batt and your index finger should dig into the pinch point of the bowl, parting the clay in order to help define the exterior shape of the bowl. Let the left hand ride on the rim of the interior to keep it from being pushed inward by the right hand.

Step 6:
With the wheel moving slowly wipe the entire bowl down with a damp sponge to finish and smooth the surface. You're finished!

Tips & Warnings
The quicker you work the greater likelihood you'll succeed in making your bowl. If the clay begins to dry out there's a good chance it'll crack while you're working it, but adding more water to clay while working it will weaken it too much to keep its shape.
The larger you make your bowl the greater chance it will become unbalanced and collapse. You might want to start with a small bowl and slowly increase the size of each successive piece.

How to Throw A Pitcher on a Pottery Wheel

How to Throw A Pitcher on a Pottery Wheel
A Simple Clay Pitcher Made With A Potter's Wheel
This piece will test your skills in pottery throwing by converting a simple clay cylinder made on your potter's wheel into an elegant and useful pitcher.

Things You’ll Need:
Potter's Wheel

Clay Cylinder

A clay coil

Knife

Engobe

Paint brush

Damp sponge

Throwing A Pitcher
Step 1:
Start with a centered and pulled clay cylinder on your potter's wheel. This guide is too advanced if you don't already know how to do this. Start up the wheel to a speed with which you are comfortable and cup the top third of the cylinder with your hands. This should begin to narrow the top of the cylinder.

Step 2:
Place the index and middle finger of both hands inside the cylinder and gently pull outward. This should give the pitcher a round body with an outward curving throat. Press down and outward on the very top lip to roll the lip over and reinforce it.

Step 3:
Use your fingernail or the tip of a knife to cut lines at regular intervals along the throat of the vessel. Your other hand should be on the inside of the pitcher to provide support and keep it from caving in. This step is purely ornamental and need not be done, but I find it helps give the piece a much needed sense of definition.

Step 4:
Stop the wheel and press the first two fingers of the left hand against the outside of the vessel while the right index finger pulls the clay out between them. The clay should still be pliable enough to form a simple spout.

Step 5:
Take your coil of clay, which should be about as thick as your thumb and twice the length of the pot and cut the ends off so you have two completely flat ends. Rough and wet the clay of the vessel at the center of the pitcher's neck and the center of the body. Attach the coil to the two roughed spots to make your handle. Smooth the surrounding clay with a damp sponge.

Step 6:
After letting the pitcher dry for a few hours, use the paintbrush to apply the engobe in a decorative band around the base of the pitcher. Any other design you would wish to use is your choice, but the pitcher should have some sort of decoration in order to really look finished.

Tips & Warnings
If making a large pitcher, a ceramic adhesive at the points where the handle connects may be required to hold the weight of the handle. Depending on the type of clay used, you may have to glaze the interior and exterior of the pitcher if it's going to effectively hold liquid.
Some fired clay is too porous to hold liquids, make sure you know the properties of the kind you're using before starting.

How To Make Plaster Batts

Plaster or Plaster of Paris is often used to make molds and other tools for pottery. This guide will show you how to prepare plaster and then use it to make a bat for a potting wheel.

Things You’ll Need:
Plaster Mix
Water
Mixing Bucket
Pie Tin S
traight Edge or Ruler
Oil or Vaseline

Preparing Plaster
Step 1:
There are many different kinds and brands of plaster, but the best type for a potter is the U.S. Gypsum Company's pottery plaster. It comes in 100 pound bags or 250 pound barrels, but much smaller amounts are sold by ceramic supply dealers. Only ever buy as much as you will need for a project, plaster does not keep well unless it can be sealed in a completely airtight container. The correct proportion for mold work is 2 3/4 pounds of plaster to one quart of water.
Step 2:
When mixing, measure the water first and put it in a plastic bucket or mixing bowl. Sprinkle the plaster lightly and slowly into the plaster to prevent it from clumping.

Step 3:
When all the plaster has been sprinkled in, allow it to slake for two minutes. Slaking is letting the plaster body absorb the as much of the water as it can. Not doing this results in dry spots and cracks in your mold.

Step 4:
Once the slaking is complete, pour out any water remaining on the top of the mixture.

Step 5:
Stir the mixture by hand. The stirring should be done in such a way as to agitate the mixture and drive out air bubbles. Do not whip or whisk the mixture. The point is to get air out, not in. A good method of stirring is to put the hand, palm upward, on the bottom of the pail and wiggle the fingers vigorously. Continue to mix for two or three minutes.

Step 6:
The plaster should begin to thicken. You can tell its ready when a finger can be drawn over the surface of the mixture and leave a slight trace.

Pouring A Plaster Bat
Step 1:
Take a pie tin between six and eight inches in diameter.

Step 2:
Use cooking oil or Vaseline to lightly coat the interior of the pie tin.

Step 3:
Pour the plaster into the pie tin in a spiral pattern. To ensure that the bat will be of even thickness, let the mold overflow with the plaster and simply scrape the top smooth with a ruler or straightedge.

Step 4:
Freshly made plaster will need to dry for five or six days before it can be subjected to the stresses of use. To speed this process, place the mold near a warm radiator. Don't let it become hot to the touch as the plaster will be weakened and crumble. Infrared lamps are the best way to quickly solidify plaster as they can dry the plaster from the inside as well as the outside.

Step 5:
Once the plaster is completely dry simple overturn the pie tin and your new plaster bat should slide free. Enjoy!

Tips & Warnings
When mixing, sprinkle the plaster into the water slowly. Never pour water into plaster. Store plaster in an airtight container, otherwise it will absorb moisture from the atmosphere and go bad. If your plaster contains lumps, sift before using it. A dirty scum on the surface of the water when you are mixing indicates that the plaster is old and no good. Plaster can be cast against moist clay or glass without the using of a parting compound. Wood and metal surfaces should be oiled or greased before plaster is cast against them, and plaster surfaces should be soaped or "sized". Be thorough when you apply size, you should use a solid bar of soap, not liquid soap. Take pride in your work. Even though the things you make of plaster are for temporary use, make them with care and accuracy.

Too much plaster in your mix results in plaster too hard and dense. It's not absorbent enough to be used in molds. Too little plaster in your mix results in plaster that flakes and crumbles easily.

How To Center A Cylinder On A Potter's Wheel

Forming a cylinder while working with a potter's wheel is common. What many don't know is that it can be a test of sorts. When a potter can successfully through a cylinder, and find that it is perfectly centered and completely even in all proportions it is proof that the potter is ready to begin forming more difficult and special shapes. Also, throwing a simple cylinder is the first step to making many different types of pots and vases. To that end here are step by step instructions on how to correctly through a cylinder and check to see if it is even.

Things You’ll Need:
Potter's Wheel
Clay Ball
Stick Sponge
Sharp knife

Throwing The Cylinder
Step 1:
Slam a ball of clay hard down on the wet batt covering the head of the potter's wheel. This will add suction to the bottom of the clay and keep it attached to the batt.

Step 2:
Start the wheel slowly with your hands cupping the clay ball so that it is evenly rounded and shaped.

Step 3:
When the ball is centered, press downward with the thumbs to make a depression in the top.

Step 4:
Brace the left hand against the mound of clay and, resting the right hand on the left, press the fingers of the right hand down on the middle of the mound to enlarge the opening.

Step 5:
The opening should go down far enough to leave a 3/4 inch thickness at the bottom of the piece. If you can't tell, use a toothpick, press it all the way down in the center and measure how much of the toothpick comes up wet with clay on it. Don't worry about the hole, that will be covered as you continue to work the clay.

Step 6:
The clay is now shaped like a low squat bowl with a thick wall. Let the wall turn in your hands for a while with your left hand on the outside and the fingers of your right on the inside. They should be exerting almost not pressure at all.

Step 7:
For this next step, slow the wheel down slightly as we will be doing the Pull up technique. Put your right hand on the outside of the piece and your left hand on the inside, with the thumb of the left hand brace against the right wrist.

Step 8:
Press the clay between the index finger of the left hand and the first knuckle of your right. Bring your hands straight up. Your left thumb, braced against your right wrist, will help you keep your hands the same distance apart so that the wall of the cylinder will be even in thickness.

Step 9:
Repeat this process two or three times, each time making the wall thinner and higher.

Step 10:
keep the piece cylindrical. The top will have a tendency to become wider and turn the cylinder into a bowl, do not let this happen. Using both hands, pull the top together to keep it the same width as the base. Try to make the cylinder six inches tall, taller if possible, but six inches should be difficult enough.

Step 11:
The top edge of your cylinder will probably be uneven, so it will be necessary to trim off a narrow strip. Brace both hands in position and hold the left index finger against the inside of the rim while you press the point of the knife toward it from the outside.

Testing The Cylinder
Step 1:
With the finished cylinder before you and the wheel locked in place, put your knife on the top edge and cut straight down to the bottom. Then do the same thing to the other side.

Step 2:
Cut through the base and remove one half of the cylinder, so that you can look at the cross section. Is the wall even in thickness and only slightly heavier at the bottom? is it free from thin spots?

Step 3:
If not than you need more practice making cylinders before you can progress. If the cylinder is perfect, then congratulations are in order

Tips & Warnings
Remove the water that collects on the inside of the piece with a stick sponge. The fewer times you need to pull the piece upward, the lesser likelihood that the piece will collapse.

Use just enough water to keep the work lubricated, too much will cause the walls to weaken and slump. Remember you probably won't get this right the first time around, so don't be too hard on yourself.