13 August 2010

Kiln Plan: Noborigama with Extended Firebox and Step-grate








So here are the plans for my Noborigama which features an extended firebox and step-grate system. I am expecting the extended firebox to act similar to a train kiln, depositing a lot of ash on the pottery and other clay work, while the chamber behind the firebox should have minimal ash. It will be constructed out of large, industrial, rotary kiln brick and standard high duty firebrick.

After reading Dick Lehman's article "An Approach To Long Woodfire" I was sure that I wanted to build in the "step-grate" system he mentioned. The nearly four feet of stepping grate (which has mouse holes coming underneath it... maybe gopher holes would be more appropriate in this case) should allow me the option of stuffing the firebox with wood and very slowly firing accumulating ash for a few days before really kicking off the firing. 


The last picture shows the kiln with its side cut off to better show the step grate... I may even add one more row of brick to the length of the firebox, extending the top step. This would add another 8" roughly to the firebox.


The design needs a little bit of tweeking and dimension checking, but is nearly ready to go. 

3 comments:

Lee Love said...

Mike,

Dick's steps are steeper. You could add that, by making the stoke end higher. Also, at the end of the steps, Dick has a floor where he puts his anagama type work. It is higher than your floor at the end of the steps. That's the whole point of building up the ash, because your bag wall will keep it from going heavily into the second chamber.

Have you consider mouse holes below your stoke area for the back chamber? It could help keep you from drawing ash over cooling pots in the firemouth, if you put pots there.

Tim See said...

This may not be appropriate for this kiln, but moving your steps to travel from side to side would allow you more staking space and less worry about sending those large pieces of wood into the first row of work. It may also get you an entrance from the front.

Michael Arnold said...

Lee,

Thanks for the tips. I was able to see what you are talking about in "Alternative Kilns" and will make the change in the first chamber that you recommend. Also, the lack of a mouse hole in the second chamber was an oversight. Thanks for bring it up.

I will post the altered design soon.