mel jacobson on thu 28 mar 02
gas.
i think it is good to remind folks that firing with gas
is a constant ballet of change.
weather, wind, air pressure all make things change.
how much gas you use.
how far the damper is in
size of the flue
control of primary air
control of secondary air.
when you are firing it is critical that you try different things.
learn what your kiln does at max gas, low gas....does your
kiln heat top or bottom fastest. /?
some simple rules.
high gas pressure will normally fire a down draft kiln hot
at the bottom...low gas will give you a hot top. reverse that for
an updraft.
(in general)
learn to adjust your burners in different ways...one on full, one
on low. see if you can move the heat across the kiln. reverse it
and see what happens. have pyrometer holes around your
kiln..just take out the lead and insert elsewhere.
if your kiln stalls, turn down the gas...see what happens.
if your kiln stalls, turn up the gas and see what happens.
don't ever leave a kiln just firing if it stalls. do something..change
things...chart it.
i have found over and over that people just turn up the gas pressure
when things go bad. should not do that. see what happens
when you drop the gas pressure.
learn the dance.
high gas, damper in slightly. back pressure 3 inches at spy hole.
now, turn down the gas, move the damper in....keep the
3 inches at the spy hole.
do different things with your kiln, gas up, gas down, damper in, damper
out. keep the 3 inch flame from the kiln spy hole. chart everything
and keep simple records.
note the weather
note the air pressure..high or low.
wind direction and speed.
see how the kiln reacts under high wind stress.
see how you can compensate for high wind.
do you lower the gas, or increase the gas...damper way in
with low gas, or way out with high gas.?
these are things you must learn about your kiln.
rarely is it:
turn on, fire, turn off.
oh, shit. bad firing. wonder what went wrong.?
see how firing down works. how does it alter your glaze.?
see what a crash cool will do. celedon's, temmoku...love
crash cool.
red, shino, iron red....love slow long cool.
(in general, your mileage may vary.)
always chart thick glaze, thin glaze..normal glaze. what does
it look like in different parts of the kiln.
at some point, place a cone pack on every shelf.
yes, every shelf. see how the kiln fires.
firing is science...yes, simple science, but alas...it is
rarely art. learn how to control your kiln...make it a part
of your being...(is that art?)
when your kiln is nearing cone nine...turn everything
down to low...open damper a bit. see how long it takes
to drop ten. you will be surprised. often it speeds up
dramatically at low gas. oxygen, what a concept.
mixed with gas, it gets hot.
far too often people want a firing instruction book.
it does not work. knowledge of the kiln is what counts.
every area, mountains, plains, sea coast. they are all different.
how much oxygen is in your air? winter, summer, 95 and humid.
-54 F. kiln is different. air is different. what do you do then.?
thoughts and things to think about.
there are never hard and fast rules.
keep people away from you when you fire.
do not make plans for dinner or a party on
firing day. leave an extra five hours at the end.
you may need it.
turn off the phone.
start in the morning, when it is calm, both wind, and
people. keep checking, but, do not stand around the kiln.
check it and leave.
be very careful for the first two hours. or, at least until your
kiln has color. kurt suggests you put charcoal in front of the burners
if you do not use pilots. if they go out, the charcoal will
re/ignite the burners.
i use wood during the reduction phase. just slip small pieces
into the fire alley. if i am doing shino, i add a cone 011 at the
front of the big cones. shut up the kiln and add wood when it
drops. smoke the bejesus out of the kiln. black shino. it you do not get it
before 011 it may be a waste of time.
it will be nice shino...but the carbon will not trap very well.
once i set my kiln into reduction, i leave it there the entire
firing. do not mess with it much. nice gentle reduction.
seems to fire best that way. hard reduction all the way will
just waste fuel. it conditions change, i change.
i have a simple old analog pyrometer. have pen lines all over
it. i try to hit marks on the pyrometer at certain times.
seems good to do that. if i do not hit a marker, i check to
see what is going on. change things.
then hit the marker.
experience teaches a great deal. you must give yourself
experiences when you fire. you must create problems.
it is like flying...you do not learn what to do when the plane
is crashing..you learn how to prevent the crash. quick thinking.
it works. but, only if you know what to do and train for it.
mel
From:
Minnetonka, Minnesota, U.S.A.
web site: http://www.pclink.com/melpots
venpot on thu 28 mar 02
Fantastic ideas, and experienced long firings are the best to get good
pots out of your kiln, I mean your own kiln, and even after this, firing
is not a good one, and have to start the experience once again.
damper in, damper out, adjusting burners, set your reduction; all of these
and you're alive!
best wishes
Minerva
venpot - venezuelan potter
----- Original Message -----
From: mel jacobson
To:
Sent: Thursday, March 28, 2002 11:14 PM
Subject: simple ideas of firing (long)
> gas.
>
> i think it is good to remind folks that firing with gas
> is a constant ballet of change.
>
> weather, wind, air pressure all make things change.
>
> how much gas you use.
> how far the damper is in
> size of the flue
> control of primary air
> control of secondary air.
>
> when you are firing it is critical that you try different things.
> learn what your kiln does at max gas, low gas....does your
> kiln heat top or bottom fastest. /?
>
> some simple rules.
>
> high gas pressure will normally fire a down draft kiln hot
> at the bottom...low gas will give you a hot top. reverse that for
> an updraft.
> (in general)
>
> learn to adjust your burners in different ways...one on full, one
> on low. see if you can move the heat across the kiln. reverse it
> and see what happens. have pyrometer holes around your
> kiln..just take out the lead and insert elsewhere.
>
> if your kiln stalls, turn down the gas...see what happens.
> if your kiln stalls, turn up the gas and see what happens.
>
> don't ever leave a kiln just firing if it stalls. do something..change
> things...chart it.
>
> i have found over and over that people just turn up the gas pressure
> when things go bad. should not do that. see what happens
> when you drop the gas pressure.
>
> learn the dance.
>
> high gas, damper in slightly. back pressure 3 inches at spy hole.
> now, turn down the gas, move the damper in....keep the
> 3 inches at the spy hole.
> do different things with your kiln, gas up, gas down, damper in, damper
> out. keep the 3 inch flame from the kiln spy hole. chart everything
> and keep simple records.
>
> note the weather
> note the air pressure..high or low.
> wind direction and speed.
> see how the kiln reacts under high wind stress.
> see how you can compensate for high wind.
>
> do you lower the gas, or increase the gas...damper way in
> with low gas, or way out with high gas.?
> these are things you must learn about your kiln.
>
> rarely is it:
>
> turn on, fire, turn off.
> oh, shit. bad firing. wonder what went wrong.?
>
> see how firing down works. how does it alter your glaze.?
> see what a crash cool will do. celedon's, temmoku...love
> crash cool.
> red, shino, iron red....love slow long cool.
> (in general, your mileage may vary.)
>
> always chart thick glaze, thin glaze..normal glaze. what does
> it look like in different parts of the kiln.
>
> at some point, place a cone pack on every shelf.
> yes, every shelf. see how the kiln fires.
>
> firing is science...yes, simple science, but alas...it is
> rarely art. learn how to control your kiln...make it a part
> of your being...(is that art?)
>
> when your kiln is nearing cone nine...turn everything
> down to low...open damper a bit. see how long it takes
> to drop ten. you will be surprised. often it speeds up
> dramatically at low gas. oxygen, what a concept.
> mixed with gas, it gets hot.
>
> far too often people want a firing instruction book.
> it does not work. knowledge of the kiln is what counts.
> every area, mountains, plains, sea coast. they are all different.
>
> how much oxygen is in your air? winter, summer, 95 and humid.
> -54 F. kiln is different. air is different. what do you do then.?
>
> thoughts and things to think about.
> there are never hard and fast rules.
>
> keep people away from you when you fire.
> do not make plans for dinner or a party on
> firing day. leave an extra five hours at the end.
> you may need it.
>
> turn off the phone.
> start in the morning, when it is calm, both wind, and
> people. keep checking, but, do not stand around the kiln.
> check it and leave.
>
> be very careful for the first two hours. or, at least until your
> kiln has color. kurt suggests you put charcoal in front of the burners
> if you do not use pilots. if they go out, the charcoal will
> re/ignite the burners.
>
> i use wood during the reduction phase. just slip small pieces
> into the fire alley. if i am doing shino, i add a cone 011 at the
> front of the big cones. shut up the kiln and add wood when it
> drops. smoke the bejesus out of the kiln. black shino. it you do not
get it
> before 011 it may be a waste of time.
> it will be nice shino...but the carbon will not trap very well.
>
> once i set my kiln into reduction, i leave it there the entire
> firing. do not mess with it much. nice gentle reduction.
> seems to fire best that way. hard reduction all the way will
> just waste fuel. it conditions change, i change.
> i have a simple old analog pyrometer. have pen lines all over
> it. i try to hit marks on the pyrometer at certain times.
> seems good to do that. if i do not hit a marker, i check to
> see what is going on. change things.
> then hit the marker.
>
> experience teaches a great deal. you must give yourself
> experiences when you fire. you must create problems.
> it is like flying...you do not learn what to do when the plane
> is crashing..you learn how to prevent the crash. quick thinking.
> it works. but, only if you know what to do and train for it.
> mel
>
>
>
>
>
>
>
>
>
>
>
> From:
> Minnetonka, Minnesota, U.S.A.
> web site: http://www.pclink.com/melpots
>
>
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__
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>
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>
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melpots@pclink.com.
>
Dupre Mr Marcy M on fri 29 mar 02
mel,
Reading this post, I mentally saw "the dance." For the first time ever, the
concept of the dance we potters do became more than an abstract.
I do not know if it has already been done, but you might consider--in your
copious spare time--putting together a book titled, "the dance."
This post is an excellent chapter outline.
For the rest of us, consider the powers we exercise of altering dirt to
durable beauty. Earth, water, air, and fire combine with the talents in our
hands to create. That creation is a gift and a responsibility.
I recently had a discussion with someone whose imagination had been stunted
during childhood. He felt that wasting one's time doing kindergarten crafts
was beneath his dignity. Couldn't see the purpose or the function of this
pottery stuff. Silly.
I pointed out to him that there were vewry few aspects of his life that did
NOT involve ceramic science, art, and craft in some form. Discounting the
obvious dinnerware, from the toilet he used on waking up in the morning to
the mild abrasives in his dentifrice he used before bed in the evening, most
of his waking life is touched by the earthy elements. I asked him to
consider the tiles on the space shuttles, the valves in artificial hearts,
"store-bought" dentures, the bases for semi-conductor chips in
computer-controlled electronics, the incandescent and phosphorescent
lighting in his home and office, the paper he uses, and the thousands of
other ways ceramics are used in our lives.
Sadly, he was not impressed.
My point is that we get the more fun side of the science, art, and craft of
ceramics. We get "hands on." We get "the dance." It just don't get no
more funner than that! I feel there is that "inner child" in me who didn't
get quite muddy enough many years ago. I am, at age 57 making up for lost
time. Despite the derision from the other folks in my workplace, I'd much
rather sling mud than bat a small ball around a pasture, any day!
Here's to "the dance!"
Thanks for the philosophical moment, mel.
Tig
Play Dirty!
Lee Love on fri 29 mar 02
----- Original Message -----
From: "mel jacobson"
> i use wood during the reduction phase. just slip small pieces
> into the fire alley. if i am doing shino, i add a cone 011 at the
> front of the big cones. shut up the kiln and add wood when it
> drops. smoke the bejesus out of the kiln. black shino. it you do not get it
> before 011 it may be a waste of time.
> it will be nice shino...but the carbon will not trap very well.
I put up a photo of a carbon trap test (John Baymore's recipe
with Mashiko materials) just for Mel. In the photo, two henko (paddled bottles)
are pictured. The one in front is a nicely cratered carbon trap (I knew the
craters would happen because the soft bisqued really bubbled when I glaze the
outside) and behind is a larger henko I ran a wavey cheeze cutter over and put
white zogan inlay on it. It is glazed with the standard Nami Jiro (half wood
ash/half ball clay with kaolin added):
http://www1.ocn.ne.jp/~ikiru/henko.html
--
Lee Love In Mashiko Ikiru@kami.com
"The best pots for me are the pots that I like." --Shoji Hamada (1894-1978)
http://www.awanomachi-tcg.ed.jp/mashiko.html
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