Making Pottery

Answers to Frequently Asked Questions

How to... buy, build, do, glaze, paint, fire, throw or learn about making pottery.

Find answers about throwing pottery, pottery clay, glazing and painting clay pots.

Read equipment reviews, buy ceramic supplies, free online pottery wheel lessons.

Think of this as your online how to pottery book, video and free personal pottery teacher.

Learn about making pottery with a wheel, whether at home, in a studio, with kids or adults.

Also learn how to make clay, buy pottery equipment, pottery glazes, and much more.

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FAQ's

General Pottery Questions

Why is it called pottery wheel "throwing" or "throwing" clay? - Some say it is called throwing because many potters, when making pottery, actually throw the clay onto the wheel to make it stick.

Others argue that it is called wheel throwing because the origins of the phrase "to throw" means "to turn" or "to twist", like the turning of the pottery wheel.

I think it's because when you mess up a pot that you've been working on all day, you want to throw the clay out the window.

Firing Pottery Questions

What is a pyrometric cone?- Pyrometric cones are specially formulated cones of clay material designed to melt after they have experienced a certain amount of "heat work".

They range in temperature from lowest 022 to highest 10.

What is High Fire Pottery? - High fire pottery is made of clay and glazes that work best when fired in the kiln between about cone 6 and cone 10.

This heat range generally makes pottery strong, less porous, and more durable for functional pottery such as dinnerware. Much of the high functional food use pottery for sale by potters is high fire.

What is Low Fire Pottery? - Low fire pottery clay usually fires between cone 05 and about cone 2.

Lowfire or earthenware pottery is created by adding frits and fluxes to the clay to make it melt at a lower temperature.

The benefits of earthenware pottery are two things:

1) Lower firing temperatures means it is easier, quicker, and less expensive to fire the pottery kiln. This gives more people access to making pottery.

2) It also makes some colors easier to achieve in glazes. The high temperatures of high fire glazes tends to cook the brightness out of them.

While bright reds, oranges and yellows are not impossible in high fire kilns, they are much easier in low fire kilns.

There are also drawbacks:

1) Low fire tends to be more porous making it less water tight for use with dinnerware.

2) Earthenware is also less durable due to the added minerals required to melt it at lower temperatures and therefore more prone to chipping or breaking.

(Keep in mind these are generalizations and there are always exceptions).

What is Earthenware? - Earthenware is basically another name for low fire pottery (see discussion above).

Pottery Glaze Questions

What is glaze? - Glaze is a mixture of minerals suspended in water.

When pottery is coated in glaze and fired, the glaze fuses into a glass-like surface, adding decoration and durability to the pottery.

How Do I Make My Own Pottery Glazes? - Making customized pottery glazes is the subject of years of study for many potters.

Each glaze recipe is formulated then tested color, quality, firing temperature, and "fit" with any chosen clay body.

In a nutshell, glazes recipes are formulated by combining different amounts of glaze minerals, mixing them with water, applying them to the surface of a pot, and then firing them to see what happens.

You can buy glaze books with tried and true recipes. You can also buy premixed glaze recipes wherever you purchase ceramic supplies and modify them by combining them or adding minerals to them.

Finally, you can formulate your own glazes by experimenting with different glaze ingredients (also available at many ceramic supply stores) to formulate your own.

How Are Pottery Glazes Applied to the Pot? - The most common ways pottery glazes are applied to pots is by spraying the pottery, dipping it, pouring glaze over the pot, or painting the glaze onto the pot in 2-4 layers.

Pottery Clay Questions

What is clay? - Clay is a naturally occurring collection of minerals with fine particle size.

Clay naturally holds water, hardens when dried and fired, and holds it's shape well when formed and stretched. This stretchability is known as plasticity.

With practice you can learn how to throw pottery clay into functional projects and then fire them to make them permanent.

What is a Clay Body? - A clay body refers to the makeup of the clay based on it's individual ingredients.

Different projects require different clay bodies and therefore different amounts and types of ingredients.

The ingredients of the clay body determine whether the color is white, buff, brown, red, or a brightly stained color.

They also determine the firing temperature, and what can be created with the clay.

Some have more grog (a sand-like clay material) that adds strength and reduces shrinkage.

Others have more of one type of clay, such as Kaolin, stoneware, or Ball Clay.

Still others have fluxes that cause them to melt (or vitrify) at lower kiln firing temperature.

For example, if you are making quality pottery dinnerware you would probably use a smooth clay body with a low grog content and a higher firing clay for durability and water tightness.

What is wedging? - Wedging is the process of kneading pottery clay to remove air bubbles, mix it to consistency, and align the clay particles to aid in wheel throwing.

There are two main types of wedging: spiral kneading and table wedging.

What is spiral kneading? - Spiral kneading mixes and removes the air from clay by stretching and pressing it into a table. As the clay is rotated it takes on a spiral shape.

What is table wedging? - Table wedging involves pounding the clay on the table, then cutting it in half, flipping it over, and pounding it back together again until it is smooth and bubble free.

What is porcelain pottery clay? - Porcelain clay is usually a white high fire clay high in Kaolin.

It often is fired to cone 9 or 10 in the glaze kiln. Porcelain is excellent for delicate sculpture, dinnerware, tea pots and sets, and tile.

When thrown thin enough it has a translucent quality like a sea shell. It takes on an ethereal glow in the right light.

It is generally less "plastic" or stretchy than other functional clays and is therefore used less often for large pots such as floor vases.

What is pottery stoneware clay? - Stoneware is an sturdy, opaque clay excellent for functional potters making pottery projects such as dinnerware, cookware and bakeware, mugs, plates and bowls.

It is also a high fire pottery clay making it well vitrified and less porous than most clays. This and it's durability make it great for use with food and dinnerware with the right ceramics glaze.

How can I reconstitute old, dry clay? - This is a common question and a good one. First begin by breaking it up into small pieces.

Next, place it in a bucket and add water until it just covers the clay. Let it soak for a few days while the clay softens.

Once it has softened, you can then use a mixer attached to a power drill, or even just a heavy stick... anything to stir the clay with.

Stir the slurry mixture until it is well mixed. It shouldn't be too runny... like pancake batter is a good consistency. If it is too runny, you may need to add some more clay to thicken it and then let it soak some more.

Finally, pour your "batter" onto a plaster bat, or into a pillow case or other fabric like the leg of pair of jeans.

The reason for the plaster or fabric is that it will absorb and wick the moisture away from the clay more quickly. It will need to dry like this for about a day to several days.

Check it periodically. When it gets close to a more doughy consistency, it is time to wedge it thoroughly.

Once you have wedged it thoroughly, it is ready to throw on the pottery wheel. Wedge it well and put it back in the bag to store until you're ready to use it. You can literally store pottery clay for years. In fact, it often gets better with age.

TIP: You want to error on the moist side when you start to wedge the clay because the wedging process will actually cause it to dry out a little more. You can always let it dry longer if it's too wet, but it's tough to add water back in.

Also, if your clay gets just a little dry while in storage, you can wrap a wet dish towel around the lump of clay and put it back in the back.

Wait a few days or a week and you will have softer clay. Just be sure to rotate the bag so the water doesn't pool in the bottom and wedge it thoroughly before throwing on the pottery wheel.