Although we have owned this kiln for a year or so, we have never fired it before…didn’t have anything to fire. So <insert drum roll>, we did our first bisque firing to Cone 04 yesterday. It took 4.5 hours, which is pretty good. A bisque firing is the first firing that heats a piece of greenware (dried clay) until it’s solidified. It is now called bisque ware and will be fired again once it’s glazed. I fired a vase, bowl, a couple ‘things’ a neighbor girl made and a bunch of glaze color tiles.
The tiles were low fire clay and once glazed will be fired at the same temperature as the bisque fire and will then be considered earthenware. The vase exploded (not quite bone dry when put in the kiln). The 2 bowls are high-fire clay and will be heated at a much higher temperature (Cone 6) once glazed. They will then be considered stoneware.
Earthware is not as durable as stoneware and is usually used for flower pots, etc. It is still porous and will leak if not glazed. Those cute coffee cups that chip real easy are usually earthenware. Stoneware is much more durable, is not porous and does not require glazing to hold liquids. It can also be heated, so most ovenware and often used items are stoneware.
I just started pottery in February and am learning as I go, so I’m sure there is much more detail I do not yet know and many different ways to do the different steps…I post what I know. :-)