Just got back from unloading my wheel, some supplies and clay over where the gas kiln is located(I guess I'll start referring to it as the clay studio in time:)
White is the hottest, highest temperatures you can imagine(it's also the combination of all colors of the spectrum :)
At temperatures(or color) above orange you start to need welders glasses to see anything inside, the color is that bright. This is important. While I do have pyrometer for my gas kiln, I only use it till about 1800°. After that, I rely solely on pyrometric cones* and the color inside the kiln- viewing through peep holes with the naked eye at about a foots distance- saves on eyebrows and beard hairs<G>
Pyrometric cones are basically pyrmidal shaped clays made to bend/melt at exact temperatures. Since not only heat but soak time is required to bend cones, it's important to make a cone pack. cone packs are basically boat shaped pieces of clay that you stick the cones into just enough so they stay at about a 20° angle. For my Δ10 glaze firing( Δ represents the word cone) firing, I will have a cone 6, 8, 9, and 10 in it. When cone 6 goes down completely, I begin to reduce the oxygen going into the kiln. This slows down the heating process, but is necessary to achieve the effects of the particular glazes I use. What happens essentially is for fire to stay alive it needs oxygen. Since I am deneying it of oxygen it searches it out of the clay and chemicals in the glazes. That is why most reduction fired peices will have a dark brown, earth tone to them. Of course, with the right clay compounds, you can make a white stoneware that only turns cream in reduction. Of course, my true passion for reduction glazes is on porceline. I haven't spun porceline in about 10 years(but have about 200# of it aging nicely <BIG SMILE), the longer clay ages the more plastic it becomes. But spinning porceline is like trying to spin tooth paste. it is not very forgiving and often times difficult to achieve the wide flares and orther forms more condusive to stoneware.
Let's see, did I answer your question or just go off on a tangent? :)
Did I mention I have a dull red color now inside the kiln?
P.S> I'm not going to edit this for misspelled words, I'll lose the Δ characters |
