The firing was a success! We fired for the better part of four days and were blessed with temperate weather. This time we burned through seven chords plus...due to the use of roughly half pine plus assorted hard woods. The kiln was packed fairly tightly...and we fired to a soft cone eleven. Knowing that wood ash generally melts at 2150F...explored a slightly lower temperature range. Towards the end of the firing, we stoked the better part of a half chord of black walnut. The results were interesting on one of the clay bodies, Lehman 12D. The colorations were nice in that the flame/ash side of the pieces formed a green ash and lignt clay background...the lee side of these pieces revealed the more interesting surfaces. A chocolate flashing color accompanied matte oranges and yellows that broke to white. A totally new color range and one the we found worthy of further exploration.
Trying a new porcelain mix from Amherst Potter's Supply, there were some nice flashings of oranges and some yellows...still think I prefer the Sheffield mix. Next firing, will try another 1000# batch of the 12D and another of a body that will be decided upon in the next couple weeks. Would like to mix up a couple new small batches, 150#, of test bodies.
This firing, the eighth with the Pyranhagam, was significant for me in that it marks a point at which I feel as though we, the firing crew and myself, have gotten to know the characteristics of the kiln...stoking and stacking techniques, zones, glazes that perform well etc. For me, it is a chance to step into a new realm of firing in that the more technical question and answer dialogue is becoming subtler. My hope is to scale back to firing on a six month schedule....or better yet, whenever the kiln is filled with pieces that we've crafted with care and not rushed in any way... and focus a bit more on studio work. There are pieces that take a bit more time to create...plus ideas that would be fun to expore that I have been holding off on due to the primary concern of firing the kiln in a way that yeilds consistent quality...a daunting task consdering all of the variables involved in anagama firing.
Another discovery this time around was the use of what seemed to be excessive sawdust in the wadding mix. The recipe is sawdust with as little fireclay as possible, just enough to bind the sawdust and then a couple scoops of alunima hydrate. (a discovery many other potters have found themselves) I know that is not an exact recipe...but the result was literally a crumbling of the wadding as it was removed from the pieces. If pressed, I would say the recipe would be three parts saw dust, one part fireclay and an eighth part alumina hydrate. Rather than making balls with the wadding, which was impossible, clumps of wadding were added to spots of glue. A noticably soft line of demarcation between clay and wadded areas was a nice improvement to wadding marks of the past.
Photos to follow.