THE POTTERY OF SAN MARCOS TLAPAZOLA, OAXACA. PART II
It San Marcos Tlapazola it generally takes six days to take a vessel from clay to burnished and ready to fire. Each potter in a household might make 20-30 vessels in six days. And if there are six potters in the household, how many pots will they make in six days? Don’t bother with the math, just know that it’s enough to fill a kiln.
Except that there are no kilns in San Marcos. So how do they fire? I’ll tell you, just follow along….
Step 1). Candling. On firing day the pots are brought out into the sun at first light. They will sit there and soak up the rays for about 6 hours. This is candling, preheating the pots so they’ll be nice and hot, almost too hot to touch, before they are set in the “kiln”.
Step 2) Building the “kiln”. Around mid-day, when the sun is at its peak, the kiln, or firing space, is built. This is done in the courtyard. The first step is to build a corral like ring using old pots set upside down. The size of the ring defines the perimeter of the firing space and is adapted to the amount of pottery to be fired. If there are only a dozen pots to fire, the ring will be small, if there are several hundred the ring will be large. Call it flexible kiln sizing, it’s a cool trick! Then a layer of old tin is put down inside the ring to act as a floor. This step is optional, but serves to both reflect heat and keep soil vapor from potentially damaging the pots. On the tin is placed a single layer of firewood. The firing space is now ready.
Step 3) The tumblestack. Once the firing space is created the pots are “loaded” or stacked into the ring. The largest, round pots are set in first. They, like almost all the vessels, are loaded sideways or mouth down. In the image there are red burnished pots and tan pots. The tan pots are non-slipped, non-burnished vessels that will be sold to the piñata maker. After the initial layer of large pots is set in, smaller pots are placed on top of them. Every person who made pots that will be fired also participates in the firing, so there can be 10 or more potters handling pottery and placing them on the stack. There are a lot of opinions on the right placement of pots and thus an ongoing dialog and debate is carried on among the potters as they build the tumblestack.
Step 4) The Flame Up. As the last pots are being set in place, someone will come from the kitchen with a shovel full of embers and drop them among the pottery in a variety of places. Slowly fires will be ignited in the layer of basewood. Meanwhile the potters will cover the top of the stack with another layer of tin. Again, this is an optional step, and most potters don’t bother with it. The primary function is to keep coals and embers from settling on the pottery and leaving burn marks. The potters in this household prefer their pottery unmarred.
Wood is then placed on top of the tin. All variety of wood is used, from thick branches of oak to the dried leaves of agave plants, cow manure and dried corn cobs. Soon the fuel ignites from below and the bonfire builds to a crescendo. As the flames grow the potters watch for hot and cool spots. They will add fuel where needed and use long sticks to shift the fuelwood around. The flame up lasts about 25 minutes and the fire is tended constantly during this period. The internal temperature goes from that of sun heated pots to about 700F in under 10 minutes, then the heat slowly inches up as the wood turns into a mass of red hot coals. Just about when the fuel has flamed out and turned to ember the firing reaches it’s peak heat, which can vary from a low of 700F to about 1,200F.
Step 4) The Flame Down. Once the fuel has burned out and the flames begin to diminish, the fire is mostly left to run its course. There will be some tending as coals are moved around to compensate for cool spots, particularly on the windward side of the stack. But otherwise the potters will now sit back in the shade and mop their brows. In another 30 minutes or so the fire will have burned down completely to white and black ash. The potters will already have a pretty good idea at this point of how their wares fared, for they will have heard the popping of pots during the firing if there was going to be breakage. In fact there seldom is and the bulk of firings have no breakage at all.
Step 5). Unloading. Unloading can either happen the next day when everything has cooled down, or often enough, about an hour and a half after the fire was started. It is trickier to unload a hot stack, as each of the pots has to be plucked out with tongs or metal hooks, but is sometimes necessary because of threat of rain, or the need to have the pots ready for a client or to take to the market in short order.
Unloading a hot kiln is something like playing pick up sticks, as each vessel is oh so gingerly plucked from the stack and set down to cool. In this image two potters use tongs to remove the pottery. The tongs are actually BBQ tongs brought down by a US visitor, and they make the job easier. More commonly, a piece of rebar is used to hook the edge of the pot and it is lifted out with intense concentration and set on the ground. But I’ve never seen a potter drop a vessel. Once unloaded and dusted, the pots are ready to go.
Traditions Mexico Oaxacan Clay Workshop
January 3 -11, 2009
For more images of the San Marcos pottery-making process, see our slide show