Firing pottery in an open flame is a form of reduction fire, one in which oxygen is reduced. A full reduction fire will yield black pottery. An example of a full reduction fire is to fill a metal garbage can with sawdust and pottery. Light the sawdust on fire. After it gets burning well, place the lid on the can and let it smolder for several hours.
Firing pottery in a pit or barrel allows smoke and flame to wash over the wares. This creates black and white patterns on the pottery.
What Clay Should Be Used for Pit Firing?
A clay body with a good amount of grog should be used. The grog helps insulate the clay against the variation of temperature within the fire. As well, all objects should be bisque-fired first. If green ware is placed in the open flames of pit or barrel fires, expect a lot of breakage.
Elements of a Pit or Barrel Fire
For a pit fire, the first thing to do is dig a pit. How big the pit is depends on how much pottery is to be fired. Pots to be fired can be stacked with combustibles in and among them. Pit fires are often done on the beach because digging is easy.
For a barrel fire, all that is needed is a metal barrel with a lid. A metal garbage can can be used, or a 55 gallon drum with a barbeque lid.
Combustibles for the fire include sawdust, kindling wood, scrap lumber, newspaper, wood chips, dried manure and old cloth. Large amounts of wood aren't needed. Keep wood size to 2 -3 inches in diameter and 2 feet long or smaller.
Additives to the firing can create bursts of color. Common table salt creates a coffee brown color. Salt can be added to the fire with the combustibles or during the firing. As well, fabric soaked in salt and then dried can be wrapped around pots before firing.
Copper carbonate will add flashes of purple to the wares. Copper carbonate can be found in Miracle Gro plant food or tree root killer. Both can be purchased from the hardware store.
Dried fruit peels contain minerals which add orange effects to pottery. Popular peels include banana and cantaloupe. Seaweed is full of minerals and creates great effects, but isn't available everywhere.
How to Build a Fire
For a pit or barrel firing, line the bottom of the pit or barrel with newspaper or sawdust. Start adding pottery along with smaller combustibles such as wood chips or manure. Keep layering and add small wood chunks throughout.
Additives can be added and sprinkled throughout the fire stack. Additives can also be wrapped up with the wares. Take a piece of newspaper and open it. Lay the pot on the paper. Add banana peels, copper carbonate, salt or your choice of additives around the pot and on the newspaper. Roll the pot up with the newspaper and tie a string around it.
The trickiest part of the process is getting the fire to light and continue burning. Read up on campfire building techniques to help start a good fire.
The fire needs to burn well and fully for a couple hours to produce good results. It can go longer. There is no set time because every fire is different.
After the fire is out, let everything completely cool. This will take several hours. Remove the pots, dust off the ash, and scrub if necessary. Polish with carnuba wax for wood floors.
Cassandra Truax - Cassandra might be considered a jack of all trades. Starting out with a BA in Spanish with a minor in Environmental Studies, she decided ...
