I'm thinking this is our best firing yet. Had a lot to do with the preparedness and crew for sure. A good group of folks stoking and ample wood split, seasoned and stacked for efficient working. A big change in the stack involved a secondary firebox in the bottom center on one side. This was huge in that the flames were given a chance to completely combust...nice glaze melt and ash deposits toward the tail. This firing yeilded great results that are featured on the summer 2016 unload page.
The December firing was a good one. 3 days total.
We fired through five chords of mixed wood; pine, mulberry, black locust, maple and honey locust. We saved a stock pile of honey locust for the finish. Turns out that we fire with a different mix of woods each firing; and each wood has particular burn characteristics. It does make things a bit tricky...especially when a new wood is introduced. We had never fired with honey locust before; but I had noticed that its heat index is very high and we were thrilled to have a good bit of it (1.5 chords) to bring the kiln chamber to it's max temp. What happened baffled us for a bit. There was low pressure over the kiln for the last day and the honey locust embers built up both in the firebox and below the firebox something fierce. We tried to increase the draft by plugging passive dampers in the flue, opened up the ember box to max air, altered stoke patterns...nothing would get temp to the back of the kiln. Would have been nice to have a chord of thin-split pine for that! Next time for sure and from now on. The front and middle hit cone 10 plus and the few pieces we've pulled already show spectacular results. At the end, the near white heat indicated plenty of temp. There may be a few re-fires this time but from what we can see so far, the atmosphere of super heavy reduction was good for shino crystalization and flashing...we've seen some beautiful chocolate flashing on several different clay bodies. Can't wait to get at the rest!
Stephen Rodriguez shared a couple new glaze recipes with me for this firing and I'll post them once we've seen the overall results.
Will continue this post after the unload.
This firing was special in many ways. First of all, a great friend of mine, Michael Strand, came out to participate in the event. His presence was awesome as he has fired anagama kilns all over the world and is a world-class teacher, potter and activist.
Several other potters visited the firing as well...Stephen Rodriques of New Haven, CT. Mark Potter and Louise Harder and Kristen Muller also partook in the festivities.
For me, the best part of visiting potters was the exchange of ideas and forging of friendships. I learned more this past firing than ever before...or so it seems. Mostly, the feeling of being a part of an inclusive group of clay enthusiasts was thrilling to me.
Former students took a larger role in the firing of the kiln. Michael suggested I give even more responsibility to these folks as they have proven their commitment to the process. That'd be great, especially since my two little ones are requiring ever more parental focus as time wears on.
Regarding the firing itself, we packed it fuller than ever. The results were stunning in most of the kiln. Although the tail was packed a bit tight and we had trouble reaching max temp in that section. Always lessons to be learned...but some spectacular results.
Next time, will fire a bit faster...3.5 days for this one...next fire, Dec. 2015, will be 2.5 days with a high temp hold for 24 hours.
Will stack looser throughout and create some open channels for flame and some tightly stacked sections to create micro-climates. There'll be a larger percentage of 25 lb. plus pieces in the kiln too..looking forward to seeing broader surfaces and their variations.
The firing is slated to finish up New Year's Eve...so should be a fun finale'. Best, Trev
For me, friendships, enthusiasm and team-work are at the core of the wood-firing experience. A deep level of trust and understanding has developed over the past few years as the core firing crew has congealed. We, the firing crew, find satisfaction in taking on responsibility and welcoming opportunities to creatively problem solve. Gradually, a new aspect of the firing process has emerged, one where sharing the responsibility of overseeing and executing crucial aspects of the firing has become the tone of the firing. A big part of the value in pottery involves the friendship and bonding that is woven into the fabric of the wood-firing experience.
The June firing was huge for me personally....the success rate and overall quality was beyond my wildest expectations...yet there is a sense that a continued commitment to the process will yield information, discoveries and goals beyond any of our preconceptions. Exhillirating stuff! Planning to fire again December 2014 ;)
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.
So today is the start of the firing. The last few weeks have been busy with last minute series of pots, splitting, glazing and loading.
The kiln is packed relatively tight...we found that a tight stack and a 12 hour hold around 600F dispersed ash evenly throughout the kiln the last firing especially. Thinking the tighter front stack especially acts like a screen the draws and disperses ash throughout the chamber...a discovery based on previous firings in which we stacked looser in the front.
There are five rows deep of shelves in the kiln and the first two counting from the firebox are exclsively stoneware...have found the porcelain likes the center section best...flashing and fine ash build up.
Our plan is to fire the kiln at 180F for 12 hours then move to a 30F/hour rise to 600F...so around midnight we'll start the 30F/hour heat rise again. Our goal is to be at around 1500 by the 48th hour. At this point we will pay extra careful attention to the atmosphere so as to allow for full oxidation before re-stoking.
By hour 72, we hope to be around 2300F and work the kiln to peak temp. and hold till hour 84.
During the initial phase..up to 1500ish...the passive dampers will be pulled to the point the we get the minimum draft necessary to maintain heat climb. After this, we will increase draft only as required.
Adjustments in the firebox occur mainly when we achieve orange-heat...at this point we close off the lower/primary air arch...this serves to increase draft a bit, keeps embers from accumulating and shields the stokers from excessive heat radiation.
Once we have held at temperature for several hours...we will introduce a half chord of Black Locust to provide the heat and ash that should get us to a soft ^12.
Shut down will be as usual...a couple wheel barrows of wood in the firebox followed soon after by a complete shut down of all air ports, peep holes and active damper...this technique has proven inself to be good way to achieve reduction cooling and flashing at high heat.
Each firing is so fun and exciting...the information gathered each time never fails to inspire the next firing. By far, the most satisfying aspect of the firing is the shared experiences with the firing crew. Mostly former students comprise the crew...a good friend Jim is a major contributor to the process....making pots, loading firing and unloading/clean-up. Without these guys there's no way this event could take place...so thankful that we've all taken ownership in the process of firing the Pyranhagama...without this process...may not see these guys regularly...good in all ways!
Overlooked posting on the April 2013 firing...went well with good ash on applied-glaze surfaces. My decision was to persue custom clay bodies for the next firing in August as this is an area I would like to explore.
With regard to the August firing...a success. Blended up 10-#150+ batches of clay bodies...all of which were influenced by Jack Troy's recipes. Used Helmer and Tile6 in most bodies...EPK in some and found that bodies with Redart responded well to the firing's atmosphere and temp. range.
I had been resisting a low-temp hold early in the firing for a while and decided that along with the new bodies...we'd try holding around 600F for 12 hours or so. Along with a few other changes in firing technique...we attained the best results so far with the "Pyranhagama". We were super conscious of allowing the atmosphere to clear and oxidize between stokes as we were in the red to orange hot range...this eliminated some spotty carbon coring issues that resulted from over zealous stoking in past firings. Addirionally, we employed a steady heat rise throughout the firing...about 30F/hour throughout the 3.5 day firing (excluding the 600F hold). Finished up the firing with a large stoke followed by a shut down of all stoke and air ports along with the active damper to the flue.
Results were: even ash distrubution throughout the kiln (aside from the very front which gets nailed), ash on horizontal surfaces, subtle directional ash glaze/flashing transitions, Celadon glaze melted more than usual due to increased firing time (cone 12 just started to bend), brighter colors due to Redart/Grolleg clay bodies and small crystal haten families in the ash glaze in shielded areas.
Having just completed the firing a couple weeks ago...the results and discoveries have begun to sink in. We had a nice firing...about 55 hours that used 6 chords of mixed hard/soft green/seasoned wood.
This firing was unique in that we fired through a snow storm during the final 10 hours. The snow was light and dry...and the combination of low pressure an added moisture in the kiln provided for a unique set of atmospheric conditions. The water/gas reaction kicked in boosting the kiln temperature to a max. temp of 2360F.
The kiln was packed a bit tighter this go around...a total of 534 pieces were fired...ranging in size from small teabowls to large platters.
Cone 12 softened slightly and our shut down temp. was 2260F. This seemed to work nicely in that the flashing and color development was consistent throughout the middle and back of the kiln...the front displayed ash runs that intermingled with a both raw and glazed wares. Fired results documented in the first several shots in the Pyranhagama Pots page.