These are examples of pots that were fired using a process called pit firing. I've learned of this technique from a California potter/artist, Joe Battiatio. Its a modified version of the way pots were fired by people before people built kilns. They would dig a "Pit" and place their pots in it by stacking them on top of each other. They would then surround the stack with wood and other combustible material then fire it. Joe Battiatio's version, uses sawdust other materials to produce the colors you see. Copper carbonate produces reds and salt produces yellows. And the black is carbon, from the burning sawdust.
-dig a pit
-lay a layer of saw dust at least 3"thick.
-mix copper carbonate & fine table salt in with the sawdust.
-place pieces down
-place cow patties ( dried cow manure) on top of pots.. this is used as a thermal blanket, this burns slower than the wood used to fire this pit. this will help the pieces cool much slower
-wood is placed on top of the stack then fire
Now, I have mixed feelings with this technique and the results it produces. I don't like the black that the sawdust leaves behind and I'm not particularly fond of handling cow poop either. Also, burning a lot of wood and sawdust in the backyard is not so popular with the neighbors. So by dissecting his process and learning what materials does what, I've devised another version that produces results that i want, and won't piss the neighbors off.
Modified backyard version:
charcoal, steel wire mesh, a few bricks, copper carbonate, salt, seaweed, wood chips, kaolin fiber.
-dig a pit 2 feet deep and wide enough for all your pots. Stacking pots on top of one another produces cool patterns
-lay down a few bricks sideways
-place the steel wire mesh on top of the bricks
-add a layer of charcoal on top of the mesh
-add salt and copper carbonate on top.
-add another layer of charcoal, i like to use the instant light charcoal
-burn and wait till the first layer turns white
-add pots on top and also add sea weed and wood chips (soaked overnight in salt water) around and in between pieces.
-cover with kaolin fiber blanket lid, made from kaolin fiber sandwich between two wire mesh screens
Yes, I know, this version is a little complex but it works. There will be no flames that would attract the local fire department. In the eyes of your neighbors, it will only look and smell like your doing a Polynesian style BBQ. Just put some tiki torches up and wear your grass skirt, to make it look authentic.