Dave Pike on tue 30 sep 03
Dear Sue,
I don't fire an anagama, but it often rains during my firings. In a word,
yes, temp stops rising when it is getting ready to rain or raining. I often
get stuck at say, 1000c for 5 or more hours. The record for getting stuck
because of rain is the time we got stuck for 17 hours and then later during
the same firing for an additional 12 hours. Luckily for me I had as my
helper my freind who is the paragon of patience. After getting over that
hump, or any of the tens of others, the general total time is always between
23 and 30 hours.
As far as extending the chimney, I extended mine 3 times. The first and
second time by 30cm, the third by 90cm. My suggestion is to learn to rely on
the rythym of the draft to decide if you need surgery on your chimney, with
as a visual clue the flame distribution(how evenly it goes into the array of
flues) and speed(is it constantly being pulled in; is it coming out the
front sometimes; is it what I call breathing, meaning alternating between
being pulled through and then coming back to the front of your kiln, each
"breathe" taking 1 or 2 seconds). I find the last condition best. I would be
very cautious about changing a kiln that does what it is supposed to do most
of the time. On my kiln the spot in front of the "fire box"(dogi) is
considered the "driving seat", incidentally you can't see the pyro from that
spot; the condition of the fire box should give you most of the info as far
as draft. If the flame is not "rocking" back and forth as it comes forth
from the wood then some adjustment is needed. Also the noise of the air flow
should give you a clue. No noise=too little draft. Saying that I am
supposing you close off most of your stoking "door" except when you're
actually putting wood in, only in that situation would you have a noise. If
it fires to your satisfaction when it isn't raining I would say to not
change anything.
Water around the kiln. Hmmm. I wouldn't worry too much about that. My kiln
sits above what is essentially an underground stream. The ground is always
wet to the touch except during and immediately after firings. In fact during
my yakishime firings I sometimes spray water in if the temp goes to high.
Shiro Tsujimura, who lives 5 minutes from here, has a kiln built in a swampy
area of his land. I was first shown that kiln by his son. As we were walking
to the kiln through the mushy ground, I noticed my boots weren't, hmm,
griping the ground right. I looked down to get better footing and to see
what was crunching ever so lightly. In the same second, both the son and I
figured out that, I , who was not following in the exact footsteps that he
took, was instead crunching Mr. Tsujimuras' teabowls that he had put out to
age (ajitsuke). On the same topic, the late Fujiyo Koyama, who is my
teachers teacher,(my teacher is Naoki Kawabuchi) is said to have had water
channels (suido) running through his snake kiln. Mr. Kawabuchi doesn't use
them, as don't any of the people that I know that do the Nanban style of
yakishime. Mr. Kawabuchi gets exellent colors without water.
My 2 yen
Dave
Sue Leabu on tue 30 sep 03
On Tue, 30 Sep 2003 18:51:17 +0900, Dave Pike wrote:
>the condition of the fire box should give you most of the info as far
>as draft. If the flame is not "rocking" back and forth as it comes forth
>from the wood then some adjustment is needed. Also the noise of the air
flow should give you a clue. No noise = too little draft. Saying that I am
>supposing you close off most of your stoking "door" except when you're
>actually putting wood in, only in that situation would you have a noise. If
>it fires to your satisfaction when it isn't raining I would say to not
>change anything.
Dave, thanks for your two yen!
The stoke doors are closed completely except when adding wood. Each of the
front stoke doors has a primary air vent directly underneath just above the
ground. We monitor the sound there, and can also visually see the draft by
raking a few burning coals out and watching how the smoke is pulled back
into the vent. Too little movement and decreasing noise generally means
it's time to stoke, or time to aerate the coal pile by poking holes in it
through the vent. We can get big noise and hard draft very easily except
when it's raining.
I don't mind the stalls all that much; guess after 10 firings in 3 years
I've kind of gotten used to it. :o) Problems come in with running out of
wood, and people to stoke, if the stalls are prolonged like they were this
time. We burned almost all the reserved wood that we keep around "just in
case."
Sue
Kalamazoo, MI
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