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PIT FIRING OF CERAMICS by Renee Rose Pit firing is a very interesting process, especially if you like cow manure, digging a pit, and sitting around a fire, moving as the wind blows the smoke your way. When I lived in the Bay Area, I and some colleagues would go to the fields outside of town and gather dry cow patties. Horse droppings don't work. We have to do this in summer when they are good and dry. This is just a whole lot of fun. We store them in big black garbage bags until we're ready to do a firing. We used to fire in May and in October. We would go to a beach west of Petaluma, get there about 9:00 a.m. and start digging a long pit in the sand, about 2' deep. Each person contributes something, such as newspaper, pine needles, kindling, sawdust, or larger logs, and someone goes down the beach gathering the driest seaweed they can find. We place 3 or 4 inches of sawdust in the bottom of the pit. We place seaweed around. Some people bring dried fruit peels or other things they think may have fumes that color their pots. Then we place our pots. (Most people have burnished their pots to a high sheen. The pots have then been bisqued at a low temperature so that the grit in clay doesn't come out and take the sheen away.) Some people put some pine needles under or around their pots. The placement is important, as wherever they touch a combustible they will turn grey or black. You can make the "black spot" appear where you like, by placing the side, bottom or mouth of the pot in sawdust or pine needles. Then we sprinkle copper carbonate dust around our pots, but not on them. This, we hope, will flash a nice pink onto the pot when it reaches volatizing temperature. Then, we place the cow patties such that they make a complete lid over all our pots. This is because they make it more oven-like, and also protect the pots somewhat. They burn hot, but slowly. Next comes the kindling. Then we wad up newspaper and stick the softball-sized wads in amongst the kindling. Next we use the larger wood. We usually jokingly do a little dance around the pit, calling on the fire gods. And then we light the newspaper wads in various places in the pit. At first the fire burns very high. Later it burns down and there is smoke. You don't want to breathe the smoke. Now we wait. There are always some people just tending the fire, seeing whether it needs more wood. We take turns going for beach walks, or lying in the sun. We've each brought food to share at lunchtime. But, then, more waiting. Around 4:00 people begin to get a stick and peek under the cow patties, which are now still the pattie shape, but are ashes. Someone sees that they got a blush of grape color or pink on their pot, and gets all excited. We have to let the fire completely die and grow fairly cold, because if you pulled your pot(s) out when too hot, they would suffer thermal shock and have a high chance of cracking. But finally, we get to pull all the pots out, we ooh and aah over each others', get disappointed or very happy, get jealous of someone else's great stroke of luck. It really is luck, as except for placing a certain side in the sawdust; you can't really control anything else about this! Then we take the pots home, scrub them and wax them. So if you buy a pit-fired pot, you are looking at hours and hours of work, driving time and burnishing a pot, which doesn’t go into a "regular" piece of ceramic. These pots are very unique and the burnishing makes them wonderful to touch. Having been bisqued at a low temperature, they are more fragile than stoneware. Be careful, but enjoy all we went through for you! SAGGAR FIRED CERAMICS by Renee Rose According to the dictionary definition, a saggar is a protective casing of fire clay in which delicate ceramic articles are fired. Saggar firing has some things in common with pit firing. One is that metallic salts, such as copper carbonate or copper sulfate, iron oxide and others can be sprinkled around the piece. Another is that you can put some seaweed, or some sawdust in the saggar which will smoke your pot or turn it completely black in some places. Another thing in common is that there is no glaze, the pots are usually burnished and are wonderful to hold and touch. Here's how the process goes. Sometimes people paint several coats of an extremely fine liquid clay called terra sigillata onto their pots, let it dry, and then buff vigorously between each coat. This gives a very smooth surface, but not as mirror-like as burnishing the natural clay (with a smooth agate, for instance). From there, what people choose to do can differ. Some people want a white pot, with a few spots of grape or pink color and maybe a dark black stripe somewhere and/or a large black spot. They would then put their pot in a saggar made of strong clay, maybe put some sawdust in the bottom of the saggar, and perhaps some table salt. They might wrap a piece of wire somewhere on the pot, which when burning will leave a black line. They would sprinkle in some metalic salts, maybe throw in a piece of seaweed, put the lid on and fire the pot in a raku kiln out of doors. Charles and Linda Riggs are a couple of the best known ceramists using this method, and they have derived methods of extraordinary control over their work. Their pieces are exquisite! A saggar can also be made by placing the work in a paper sack, and painting on a thick coat of clay slip. I've been using a saggar made of two sheets of heavy-duty aluminum foil. I crumple it up, sprinkle the metalic salts around, drape some wire over the piece, and wrap it up. Then, as above, it is fired in an outdoor raku kiln. I seem to get more color with saggar firing than pit firing, but I enjoy each for its own beauty. |
