mel jacobson on wed 16 jul 03
i do not like to get labeled as a person
that is promoting `fast firing`...that is not
my intent at all.
i like to use the term, and it is a new one:
DIRECT FIRING
it means that you get right after it, no long warm
ups, just turn to high and get going.
how the kiln fires may be the same as i did twenty
years ago, and i may want those affects. i just don't
leave the kiln on overnight, and i do not turn one burner
on low for five hours, and then nurse the kiln up for
hours after that.
if the kiln is dry, the shelves dry, the pots dry and
no wet glazes...get after it. DIRECT FIRE.
it takes each kiln X amount of time to get to red heat, and
it takes each kiln X amount of time to get to reduction
temps. (could be the same )the kiln has to fill with `heat energy`.
how long
you take to get there will depend on you. you can nurse
it for days, or just turn the kiln to high and get there fast.
your firing schedule will vary greatly. it will not be the same
for any of us. i just know that old theories on slow early firing
probably do nothing for the pots, and just waste fuel.
what you do after red heat, what you do with reduction, air
and gas pressure will alter your firing a great deal.
THIS IS WHEN YOU GET CREATIVE WITH YOUR GLAZES
what you read as cone 10 is critical.
is the cone down, is it flat, is it melted?
all critical questions. how long do you fire after
the cones are down? some will fire for twenty minutes
saying....`i am soaking`. and the kiln goes to cone 12.
how even is your kiln? as the old joke with warren mackenzie.
he fired cone 7 on the bottom, 9 in the middle and 11
porcelain on the top. not good scientific practice, but worked
for him. it satisfied him. but, with good firing practice it should
have been an even kiln. cone 10.
potters would be well served to learn how to even out their
kilns, and get perfect firings to the cone wished for. now that
would be amazing. i really do not care how you get there,
or what you do...but IS YOUR KILN CONE 10, TOP TO BOTTOM,
BACK TO FRONT. ???? AND ANSWER IT HONESTLY.
those of us that are firing down can answer it with a resounding
YES, YES, YES. WE DO NOT HAVE A SECOND QUALITY POT
IN A LOAD.
so, answer your own self. if you are losing 18 percent
of your pots, you are doing something very wrong? see what you
can do about it.
and don't tell us....`well, harold smith back in 1958
at old BFU told us how to fire, and i only do it his way.`
and i ask...`what did harold know? not much. he has
been dead for thirty years, we cannot ask him.
i will listen to nils, feriz, and my new hero hank murrow.
as much as i admired old behrens, a wonderful guy. i
will listen to john and ron for glaze information.
old heros with false information should be discarded.
they should not be mocked, or scolded...they did
what they did, with what they had, they should
be admired and honored, just not listened to any
more. we are using scientific meters and practices that were not
dreamed of in 1950.
as i have said many times on clayart....my high school
science book contains nothing that is true any more.
a new planet 800 times the size of earth was just
discovered....it is billions of years older than anyone
ever thought the universe could be. matter is being
made, physics is learning new things every day. `lucy`
is almost a young chick. much older bones are being found.
and oil wells re/fill after we pump them (we just have to
wait a bit, and 100 years is a long time for modern man).
new classes of animals are being discovered, one's
we cannot see with eyes.
so, why do we fire the same way we did in 1950?
`i don't know, harold told me what to do?`
there are new heros, nils, olson,hank, donovan palmquist...folks
that are trying new and delicious things. gas/electric...small
kilns that fire rapidly and well. new ideas. kilns the size of
the work that is being produced. kilns that are made
for the work that is being produced...great new electric
kilns that will last a long time. ramping, they are being made to match
the volume and quality of the potter. we just have to have to
courage to try new things. not live in the past forever.
so we have much to learn, new terms, new ideas.
we are getting on with it.
exciting times...just like always.
mel
like mr. chan lee said 1800 years ago.
`hey wally, if you build your kiln on the windy side
of the hill it fires better.`
`screw you lee, i always fire here.`
From:
Minnetonka, Minnesota, U.S.A.
web site: my.pclink.com/~melpots
or try: http://www.pclink.com/melpots
new/ http://www.TICK-ATTACK.COM
Jennifer F Boyer on wed 16 jul 03
So, isn't there still a limit to how fast a firing your shleves
will handle? How fast is too fast re the shelves?
I don't once fire. I fire with propane in a 36 cu ft kiln using
venturi's.
My current firing schedule stays at about 300-400 degrees of
rise/hour till 1200 f and then on high to about cone 9. Then
slowly to 10 down/11bdg with a soak/fire down for about 30 minutes.
I turn on pilots for an hour, 1 burner@2 lbs , 2 burners@2 lbs,
then up my 1/2 lb increments til 3.5 lbs.
I LIKE the idea of firing faster because my kiln evens out
faster at higher pressure. I've had good luck with a limited
amount of firing down, and if I could cut an hour or 2 off the
temp rise cycle, I could add some more time onto the firing down.
What is the reason you let the kiln drop to 1900 before
firing down? If I'm not reducing much, could I just do a slow
fire-down when the kiln reaches temp at 2300 and then stop the
firing at about 1900?
Jennifer
mel jacobson wrote:
> i do not like to get labeled as a person
> that is promoting `fast firing`...that is not
> my intent at all.
>
> i like to use the term, and it is a new one:
>
> DIRECT FIRING
>
> it means that you get right after it, no long warm
> ups, just turn to high and get going.
>
--
~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*
Jennifer Boyer
Thistle Hill Pottery Montpelier VT USA
http://www.thistlehillpottery.com/
Never pass on an email warning without checking out these sites
for web hoaxes and junk:
http://urbanlegends.about.com/
http://snopes.com
~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*
Lee Love on wed 16 jul 03
----- Original Message -----
From: "mel jacobson"
> how even is your kiln? as the old joke with warren mackenzie.
> he fired cone 7 on the bottom, 9 in the middle and 11
> porcelain on the top. not good scientific practice, but worked
> for him. it satisfied him. but, with good firing practice it should
> have been an even kiln. cone 10.
"Good" firing practice? Good depends upon achieving a desired
effect. The pots I like best aren't by control freaks. Too much control,
weather it be "Mastering Glazes" or having an absolutely even kiln, stomps the
life out of the work.
I remember MacKenzie telling a story about H.S. kids visiting the
pottery. Someone asked him how even his kiln fired. He said it went from
cone 4 in one spot (his boro-lithium Green) to cone 11 in another. The kid
asked MacKenzie why he put up with such an uneven kiln. MacKenzie replied, "An
even kiln isn't worth a damn. I wouldn't have one. " He went on to explain
that with his kiln, he could fire a variety of temperature of glazes, in various
levels of reduction or oxidation. He can achieve this variety all in one
firing. The trick is, to learn the kiln and know what glazes work where.
MacKenzie marks each pot after he glazes it, with sumi ink. It burns
out and doesn't leave a trace after the firing. He writes on the pot, the
location in the kiln where it should be loaded.
My kiln is similar. In the back, where the flame enters, I flatten
cone 10 Seger cones, which are equal to cone 11 Orton. I figure it must be
cone 11 or 12 orton (will put seger cones in for 11 and 12 next firing.) In
the coolest part of the kiln, by the door at the bottom, I reach cone 5. In
the middle at the door, I reach cone 8 seger (cone 9 orton.) Also, in the
back, I get a lot of fly ash. By the door at the bottom, there is less ash.
I get flashing throughout the kiln. At the bottom by the door, my kaki,
tenmoku, nuka, hagi and sage glazes do fine. They mature early. In the
back by the flame, they get too much ash. My unglazed Shigaraki clay does
well with the flame. I don't want the kiln to be even. I would have to
give up the unglazed or the glaze work if I did.
I can fire this kiln to cone 10 Seger in 5 hours, but it looks just like
it was fired in a gas kiln: no flashing, no fly ash.
A good kiln is a kiln that produces the effect you want. An even kiln
might be an efficient kiln, but it might not be a good kiln.
~~~~~~~Lee In Mashiko, Japan http://hachiko.com ~~~~~~~~~~~~~~~~~~
* *
* The person born with a talent they are meant to use *
* will find their greatest happiness in using it. *
~~~~~~~~~~ Johann Wolfgang von Goethe~~~~~~~~~~~~~~~~~~~~~~
Hank Murrow on wed 16 jul 03
On Wednesday, July 16, 2003, at 07:22 AM, Jennifer F Boyer wrote:
> snip............
> What is the reason you let the kiln drop to 1900 before
> firing down? If I'm not reducing much, could I just do a slow
> fire-down when the kiln reaches temp at 2300 and then stop the
> firing at about 1900?
>
Dear Jennifer;
You could certainly do that. However, I imagine that Mel (and certainly
myself) starts the firing down at 1900F because that is the point where
crystallization is happening, and the coloring oxides will yield deep
color if the work is done around that temperature. My Shinos, though
soaked in oxidation at 1900F, yield great color when given 2-8 hours at
that temperature.
My remarks apply primarily to matt or semimatt micro-crystalline glazes.
Cheers, Hank
John Post on wed 16 jul 03
I like mel's ideas relating to direct firing.
In the elementary schools that I teach in, there is always a load of
dinosaurs, bowls, Egyptian mummies etc., waiting to be fired. In order to
speed up the process I load the cone 1 glaze ware in the kiln and turn all
of the switches on at once.
Of course the kiln's directions tell you to turn one switch on every
hour...(one size fits all thinking). But if I turn all of the switches on
at once, the kiln hits cone 1 before the school day is over and is ready to
unload the next day. This lets me fire the kiln more times per week,
letting the kids get their art back sooner.
I can do this, because the cone 1 glaze firing is a glossy majolica. Slow
cooling is not necessary.
For cone 6 matt glaze firings I fire up fast, but slow cool from 1800F -
1300F to give the crystals time to grow.
For bisque firings I use a tip I got from an article by Tim Freidrich(sp?)
at Orton. I hold the kiln at 185F for up to 4 hours to get the moisture out
of the ware. Then I fire up slowly to cone 04. Little kids can really make
some thick sculptural objects especially when creating dinosaurs so the slow
bisque and hold at 185F keeps them from exploding.
I have about 3-4 different firing profiles that I use depending on what I am
firing. One of the electronic controlled kilns I use lets me save all of
these profiles. So if I want cone 1 fast-fire, I hit #3. If I want my cone
6 slow-cool I hit #5. I have a slow bisque for thick sculptures and a
normal bisque for pots programmed in too.
The way that I fire my work has been shaped by what I have read on clayart
over the last 6-7 years. It started when Jan Walker and I were trying to
get iron to crystalize on the surfaces of our pots fired in electric
kilns...
I think an interesting experiment for this direct firing would be to try it
in one of the gas-electric kilns... and just adding the gas at 1900 on the
cool down.
Cheers,
John Post
Sterling Heights, Michigan
(The center of the suburban retail universe)
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