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train kiln temp variation

updated sat 5 may 01

 

Hudson Mackenzie on fri 4 may 01


from shane mickey (mickey.dan@excite.com) via hudson@potters.org

the temperature variation in wood kilns is commonplace. Rob Barnard would=
tell you to accept it, make a lower fire body for those spots. But most =
people want even temperature, guess its just the ol' fussy potter syndrom=
e. You answered your own questions in your post. The firebox throat and e=
xit flues are accross, directly, from one another. crossdraft. you said y=
ou stack loosely. This is the single biggest mistake people make when woo=
dfiring. The tendancy in new wood kiln design is to give it a gigantic he=
art! or strong draft if you will. people stack loosely allowing the flame=
to stream by quickly and thus produce little ash and little flashing. Pa=
ck the thing tight, just as you would a reduction kiln. if the draft is s=
trong enough it will climb. dont hammer on the thing, that doesnt work. j=
ust be patient and stoke calmly, use the damper if you have one. WE fired=
an anagama with the damper all the way in except for about three inches =
once, little reduction, we just stoked lighter and more frequently. My su=
ggestion is to pack the bottom a little looser than the top, heat rises, =
don't be drastic in this, just a little looser. The flame will draw acros=
s the bottom. its better to hav

e control with the damper when trying to even things out. I prefer to pac=
k kilns as tight as possible, cause if i am going to split wood, gather w=
ood, stand around a hot kiln for two to three days and drink beer, then i=
better get alot!of pots in there! if its a new kiln to you get some peop=
le to help fill and fire. fire the thing twice a month it sounds small en=
ough, the more you fire the more you learn!
shane