• Safe - All the pots are lead free. Other non-government-regulated but potentially hazardous materials, such as cobalt, manganese, copper, and uranium are kept to a minimum safe level or not used at all. Also, the clay is fired at such a high temperature that it vitrifies, or becomes glasslike. It is non-porous and won't absorb liquids to any appreciable degree so it's easy to clean.
• Dishwasher Safe - Not only are they all dishwasher safe, it is recommended that they are washed in a dishwasher. While hand washing, pottery can easily be dropped by slippery hands or bashed against a hard sink and break. The glazes are durable and can easily withstand the rigors of a dishwasher. Shino glazes are the exception. These glazes are softer and will degrade slightly over continued dishwasher use.
• Microwave Safe -Capp's potts are microwave safe. This means they will not be damaged by the microwave and the microwave will not be damaged by them. Material that absorbs and reflects back the radiation can be bad for a microwave over long term use, for example metal containers. Ceramics absorb very little and are therefore save to use. They can get hot in the microwave, however, but this will not damage them. Stoneware has good thermal shock properties. It may be risky to go from the freezer to boiling hot in a microwave and this is not recommended, however, normal use such as fridge to boiling hot is fine. The iron in the clay shows no appreciable effect regarding microwave use.
• Durable - Stoneware is more resistant to shock breakage than one would think. It is still considered fragile and can break easily, especially when hit strongly against very hard surfaces like granite counters or other ceramics. Thin parts like handles are also easily broken. Given these obvious disclaimers, stoneware holds up well in the kitchen. Most glazes are quite hard and difficult to scratch or chip. The pots seldom break from minor bumps and even dropping. Does this mean that one can throw them around or drop them and expect them to remain unbroken? No, it means that they have a good chance of withstanding occasional abuses.
• Functional -Capp's Potts are made to be used. The mugs are made to be held, the bowls are made to present and contain food. A good pot has had lots of thought put into the general design. Qualities such as the type of rim of a bowl, the lip of a spout, the strainer in a teapot, or the balance of a handle are important. Functional also extends to the way it connects with the person. If Function relied on design alone, there would be no need for a colorful glaze or applied decoration. The pot needs to connect with the soul of the user. It needs personality. I think this is best achieved by rapid throwing and with as little conscious thought as possible. The best pots are those that seem to spring up from the wheel and form themselves. So, a good pot often has had lots of thought put into the design, but little or no thought put into its creation.
• A few Favorite uses- Place your tankard or tumbler in the freezer. Stoneware has good insulating properties so this will help keep drinks nice and cold as well as hot. This is great for beer, soda, and chocolate milk!

  Use the porous nature of earthenware pots to keep drinks cool in the summer by evaporative cooling.

  Small pitchers are great for warm maple syrup at the breakfast table.

  When baking sour dough bread, it's best not to use a metal bowl so use a ceramic one! Bowls with unglazed rims are great for slippery hands.

It is important that we surround ourselves with objects of beauty and spirit in our every day lives in order to truly celebrate beauty. Saving the "good stuff" for a time that will never come is a crime. The "good stuff" should be enjoyed and used as often as one can. Pots are a great way to incorporate beauty and function in our lives, and thus a great way to lift our spirits.

There is a communication that occurs between the potter and the person using his pots. When a potter creates a pot, he has made choices constantly about subtle nuances of the pot. He has thought of its future; what it will be used for and who will use it. He is also putting into that pot his own mood and feelings. It is best if all this is done with as little conscious thought as possible. When the potter is truly in tune and centered, a little bit of his soul is trapped in the pot. This imprinting in a finished pot will speak as long as the pot exists, long after the potter is dead. All pots have this to some degree and it is that human quality that separates mass-produced pots from hand made ones. In an age of non-touch and emotional detachment from our fellow humans, hand made pottery offers a subtle way to give a little of that human touch back.

• Clay body - Capp's Potts are made from a unique blend of mined clays, each adding a desirable quality to the clay body. For example: how elastic it is for wheel throwing, how does the glaze fit on the fired body, or how well it can take thermal shock. The various clays are purchased in fifty or one hundred pound bags and mixed dry according to a recipe. This dry mixture is then mixed with water until it's the correct consistency. It is compacted some by wedging and set aside to age. The clay ages for at least one month, hopefully much more. After it's aged it is kneaded, in a similar fashion as a baker kneads bread, and is then ready to use.

  The Clay Body recipes were arrived at by test firing various recipes from books by other potters and then altering them from there to produce the desired product. It will probably change over time to improve quality, adjust for clay types becoming unavailable, or aesthetic concerns.

My Two Primary Clay Body Recipes are:

Zam-TEC-A			ST-40/TEC-A
Hawthorn Bond Fire Clay	25%		Hawthorn Fire Clay	60%
Goldart	40%		OM4 Ball Clay	20%
Old Mine Number 4 (OM4) Ball Clay	15%		Redart	20%
Silica (240 mesh I think)	7%		Custer Feldspar	5%
Custer Feldspar	10%
Redart	3%
Grog (medium)	8%

• Forming Method - Most of Capp's Potts are wheel thrown, that is, a potters wheel is used to shape the clay into the base form. Some pots come off the wheel head as a finished product, such as some vases or a mortar and pestal. Usually some alteration is needed, like handles added or sides pushed or pulled. Some pots require multiple parts to be thrown like lids and spouts.

  Throwing is fairly straight forward to explain, harder to master. A lump of clay of the appropriate size is plopped down close to the center of the wheel. The wheel is spun and the potter uses his hands to gently guide the clay into a centered state. From there, the potter opens it up by pushing down the center axis and pulling it out depending on the final shape he wants. Then the sides, or walls, are guided up using alternate pressures from one hand on the inside of the pot and the other on the outside. It usually takes one pull to even out the walls, one or two pulls to gain the height and basic form and one final pull to finish off the shape. One tries not to overwork the clay. A pot can usually be thrown in a few minutes. When the pot is finished, it is cut from the wheel head using a wire or string. This can leave decorative marks in a ring pattern on the bottom of an untrimmed pot. The pot is carefully lifted off the wheel and placed on a board to dry. Drywall is great to set a wet pot on to help keep the bottom from cracking from uneven drying.

  Once the pot has dried a bit, to a stage known as leather hard, anything that needs to be completed, like handles or trimming, is done.

  Trimming is performed by turning the pot upside down on the wheel head and centering it again. Then the excess clay can be cut away using a tool.

  After the pot is finished being formed, it is set aside to dry or it is glazed if it is to be once fired.

  Two types of wheels are used for Capp's Potts. Primarly, an electric Pacifica and a Brent kick wheel.

• Glazes - All the glazes are hand mixed from purchased raw materials. Most contain Feldspar, Calcium Carbonate, clay of some sort, Silica, and then various colorants. The recipe is mixed first by dry weight and then water is added until the glaze is a heavy cream like consistency. This is then applied to the pot any number of ways, from dipping to pouring to brushing it on. Many times, multiple glazes are used together for artistic reasons. New glazes are constantly being tested. There is as much room for artistic expression in the quality of the glaze as there is in the form itself.
• Firing - When the pots are all glazed and dry and ready to go, they are loaded into a downdraft gas kiln (fiber insulated and approximately 25 cubic feet with six burners entering from the bottom). Special high temperature shelves are coated with a mixture of silica and kaolin to prevent any wayward glaze drip from sticking to them. These shelves are set on bricks, the pots are placed on them, and then a new layer is set. It is built up until the kiln is full. Glazed pots cannot touch each other or they will stick together. Considerations also have to be made about heat flow in and around the pots, shelves, and bricks.

  Once the kiln is loaded, it is lit. It is fired slowly in an oxidized atmosphere to about cone 08, (955 degrees centigrade or 1750 Fahrenheit). It is held at this temperature and atmosphere for about an hour to burn off any organic compounds that may be trapped in the clay. After this, it is put into a body reduction for about 30 minutes and the temperature is increased slowly. After the body reduction a slight reduction atmosphere is held until cone 10 is reached, (1305 degrees Centigrade or 2380 degrees Fahrenheit). The temperature is held at cone 10 in an oxidized atmosphere for 15 to 30 minutes and then it is shut down to cool. The firing process usually takes about 13 hours. The pots can be removed once they are cool to the touch.

  Unloading a kiln is like Christmas each time because there are so many surprises. At the bottome of this page are some before and after images.

• My Glaze Firing Schedual

The full set of instructions I based this on are from the book, Chinese Stoneware Glazes by: Joseph Grebanier. Watson-guptill publications / New York or Pitman publishing / London. Pages, 19 - 21. I've made my own changes, enough I don't feel it is really the same schedule any more.


I fire in a 20ish cubic foot natural gas kiln. The kiln is designed like the MFT kiln. It is built out of BNZ-26 IFB brick. It has 4, MR-750 venturi burners. I bought them at Ward Burners, a company I highly recomend.


Glaze Fire Schedule
1. Warm up period of at least one hour during which only the pilot lights are on. Air is open and all peep holes are open and flue is open.
2. Main burners are turned on to low. After about 1hr and 15 minutes, the peep holes are closed. The flue is still left wide open, (5"). Water is driven off in the next few hours. During this stage, the gas is gradually increased (every 30 min or so) from moderate beginnings to a flame that is approximately three-quarters the intensity of the flame utilized in the latter part of the firing. (about 3.5 to 4 inches of pressure). At around 1600 ºF (870 ºC) (cone 12 ish) the flue is shut a little and gas is turned up a little more to create a light reduction or neutral atmosphere. At about 1650 ºF (900 ºC) the kiln should be a nice cherry red color. Gas is turned up to about the fullest and the atmosphere adjusted towards a very light reduction. This isn't too critical. For a darker, more heavily reduced result, reduce heavier and earlier. Some glazes need to be reduced earlier in this manor more than others, like Chun's. One could just fire oxidized until cone 08 (step 3) with good results.
3. At 1700ºF (927ºC), or Cone 08, the fullest reduction is to be contrived as follows. The flue is closed, leaving as little an opening as possible. At the same time, the air is completely shut off. In addition, the volume of gas should be decreased so the flame is long and yellow, (about 2 inches of pressure). The appearance of the reducing kiln during this period, (which should be about 45 minuts), may be somewhat frightening at first, with flames licking at leaping out of all available cracks and openings and black clouds of carbon dioxide pouring up into the hood and spouting out together with yellow flame from any opening.
4. After 45 minutes of the heaviest reduction described above, the flue opening is returned to about 3", and the gas volume is increased to the fullest firing intensity, (about 5") (that is, to what it was at prior to the full reduction phase). The air is just opened. The stack will exhibit a fairly heavy thick blue flame and the peepholes will have somewhat smoky back pressure.
5. Every 30 to 45 minutes, the air, gas, and flue openings are adjusted to produce a gradual change at the stack towards a lighter volume of blue flame (lighter reduction). At the last of these stages, the blue flame should be fully discernible, but the aim is a light reduction. Near the end the gas is still on high (5"), and the flue is mostly open (4").
6. After about 9 hours or so from the start of the firing, cone 8 or 9 should be falling. Cone 10 should fall in the next hour. After cone 9 falls, the atmosphere isn't too important, and can be neutral or even oxidized. At cone 10 stall it out and hold it at temperature in an oxidized atmosphere. (It will cool in oxidation anyway and will bring out the warm colors in the clay an generally brighten the glazes). Stalling it can be tricky as the temperature wants to continue to climb. The flue should be open and the gas just on enough to keep it from falling. This soaking period should last for about 15 minutes. If the kiln is uncooperative, just clearing the kiln of the reduction gasses should be good enough. Done. Close up all peepholes as well as the flue (if you can) and shut down everything. Don't open the kiln until fully cool or at least cool to less than 450ºF. (paper won't burn in peephole).











The Kiln in reduction.