mel jacobson on sun 9 nov 03
some of the most critical discussions
that clayart can bring to folks are
words and arguments over
bagwalls,
stacks,
kiln stacking,
flame paths'
burner size,
gas pressure.
often this discussion spills
over onto electric firing potters.
what hank has offered in a quick
discussion of hot tubs is critical
for folks building kilns. WHAT IS DRAFT?
HOW DOES IT WORK? HOW HIGH AND WIDE
IS A STACK?
i do not care a wit if people disagree with
me about bagwalls, but i want clear discussion
about `WHAT YOU HAVE FOUND THAT WORKS`
i sure know what works in kilns that i design.
and, i know that false bagwalls, tight stacking,
poor stacks, great big flu's do not work.
combine a huge flu/poor stack/tight stacking/
low gas pressure and you have a crappy kiln
in the works. and they call me to come and
fix it...then argue and fight if i want to
change things. i just leave.
if you do not have clear concepts and
stick with them, you are a wishy washy dork.
dannon is building a `gas/electric kiln in her
new studio in indiana. it will be fun to hear
stories of how it fires and turns her designs
into new pots.
she will follow next year with a new gas kiln
or, as she says. `new idea for a kiln, it is
really nice`. and, then will not tell me
another thing about it. but, she will expect
me (and a few other friends) to show up and shlep brick. `i ain'ta
too smart, but i can carry heavy objects.`
dannon's new email address:
dannon@ccrtc.com
she may not answer her friends for a bit.
she is full time getting ready to sell pots.
christmas is just around the corner.
ole o'riley
From:
Minnetonka, Minnesota, U.S.A.
web site: my.pclink.com/~melpots
or try: http://www.pclink.com/melpots
new/ http://www.rid-a-tick.com
Hendrix, Taylor J. on sun 9 nov 03
Okay Mayor and all,
From what I have read so far in fancy books etc, bag walls
are designed to divert the flame path away from a setting
and in some cases up the walls of a kiln. Am I doing okay
so far? Apparently direct flame impingement on clay can=20
spell disaster for some bodies. Others seek this impinge-
ment (anagamas).
Bag walls do more than just divert the flame away from=20
directly blasting the ware. Bag walls contribute mass to
the kiln setting as smarty pants have already said. I'm=20
willing to bet that with wood firers bag walls will effect
how and how much fly ash enters the ware too. If I think=20
of the flame and ash flow a little like water flowing=20
(forgiveme professor Ivor if that is absurd) bag walls can=20
contribute to ash dropping out before entering the ware=20
chambers, right? Changes in geometry change draft. =20
Forcing burning gasses upthen down changes draft, yes? =20
Good for some, bad for others. Oooh, how bout those=20
pieces put on top of bag walls? Yum? Yuck?
Have been reading up on wood firing and at least a few=20
builders have altered interior space to allow more or less=20
ash to fall in their settings. It seems the Bourry box (has=20
a monster bag wall yes?) can be a bit stingy with the fly ash. =20
I wish I could remember, but someone has a box situated with=20
the exit above the level of the first chamber allowing for=20
more ashing. Someone is building a wood burner here at=20
Baylor for a senior project. I said it looks like a train:=20
box chamber flu all in a straight line, front to back. =20
It has a checkered bag wall. McCoy hopes to place bottles=20
etc. in those spaces and get some interesting pots. Now=20
the gasses have to squeeze themselves through the tight=20
spaces. Can that bag wall be unbuilt, rebuilt, altered?=20
Hope so. Bag wall as important firing element. Pots as
bag wall. Ask the French.
For all fuel burning kilns, bag walls offer the firer=20
another set of variables in firing the kiln. Stack it high,
stack it low, checkered, solid, throw it out. Certainly,=20
the pros and cons of having all that extra brick (can't be=20
wimpy brick either) in the kiln better be considered. I=20
know I wouldn't want to split, cut, stack, dry then stoke a=20
bunch of wood if I didn't have to. I'm trying to picture=20
David H's modified fast Freddie at the moment but I can't. =20
Bag walls? Those fireboxes run the width of the chamber=20
and the flame runs up the opposite wall from the stoking port. =20
I bet there's just a small bag.
So, I've been talking out my keister (I ain't got nothing=20
but a widdle ol raku kiln), but there's you a discussion=20
starter, Mr. Mayor.
Taylor, in Waco
-----Original Message-----
From: mel jacobson [mailto:melpots@PCLINK.COM]=20
Sent: Sunday, November 09, 2003 6:13 AM
To: CLAYART@LSV.CERAMICS.ORG
Subject: bagwalls/stack/great discussion
some of the most critical discussions
that clayart can bring to folks are
words and arguments over
bagwalls,
stacks,
kiln stacking,
flame paths'
burner size,
gas pressure.
..
| |
|
