Anne Hunt on wed 15 nov 00
'Lo, all:
Well, a new wrinkle on the learning curve of firing the Big Dog (24cf
propane kiln), is that the posts sitting on the floor of the kiln come away
with chunks of the soft brick attached. I don't mind sanding off the soft
brick, but am not real crazy about losing part of the kiln floor.
I only truly noticed it after the last ^10 firing, when I inadvertantly got
up to ^11 or so. I usually stack three shelves high, and fire somewhat
heavy pieces. Is this abnormal, or due to the weight?
Would putting more posts under the first shelf help distribute the weight
more? Should I coat the floor with Sairset/kiln patch?
Did it mebbe happen 'cause I went too high on the last firing?
i really don't like having holes/pitting in the floor, so some advice would
be greatly appreciated.
TIA,
anne & the cats, in Sequim, where the night frost covers everything with
tiny diamonds. Now if only I could see the sun breaking through an Alaskan
ice fog....more wondrous than the sound of F-15 Jet Fuel Starters cranking
up for the morning "goes". Sigh.
Logan Oplinger on fri 17 nov 00
Hi Anne,
Place a piece of broken kiln shelf on the floor of your kiln under each kiln post. The pieces you use should be about 10 times the area of the ends of the kiln posts. Make sure you are supporting each of your kiln shelves with 3 posts (3 point support).
If there is any un-eveness in the kiln floor or in the shelves, you cannot be sure that adding more posts will distribute the weight because all the posts may not be in contact with the underside of the kiln shelf.
Also, I hope you are not placing glazed items directly on the kiln floor because glaze runs will eat into the soft brick. Place whole kiln shelves on the floor, with 3 broken pieces of shelf to support each whole shelf. Make sure the broken pieces of shelf are directly below the posts supporting the shelves above.
If it is absolutely necessary to use more than 3 posts per shelf, to insure full contact, place soft clay wads on top of each post, lower the shelf onto the clay wads and press firmly. Make the wads from fireclay & grog or kaolin & grog. (Caveat, the wads may stick to the shelves, the kiln posts, or both. Unstack carefully!)
Check your pottery reference books for more detailed infomation on how to load a kiln.
Hope this helps.
Another lurker,
Logan
Loganoplinger@pacific-ocean.com
---- you wrote:
> 'Lo, all:
> Well, a new wrinkle on the learning curve of firing the Big Dog (24cf
> propane kiln), is that the posts sitting on the floor of the kiln come away
> with chunks of the soft brick attached. I don't mind sanding off the soft
> brick, but am not real crazy about losing part of the kiln floor.
> I only truly noticed it after the last ^10 firing, when I inadvertantly got
> up to ^11 or so. I usually stack three shelves high, and fire somewhat
> heavy pieces. Is this abnormal, or due to the weight?
> Would putting more posts under the first shelf help distribute the weight
> more? Should I coat the floor with Sairset/kiln patch?
> Did it mebbe happen 'cause I went too high on the last firing?
> i really don't like having holes/pitting in the floor, so some advice would
> be greatly appreciated.
>
> TIA,
>
> anne & the cats, in Sequim, where the night frost covers everything with
> tiny diamonds. Now if only I could see the sun breaking through an Alaskan
> ice fog....more wondrous than the sound of F-15 Jet Fuel Starters cranking
> up for the morning "goes". Sigh.
>
> ______________________________________________________________________________
> Send postings to clayart@lsv.ceramics.org
>
> You may look at the archives for the list or change your subscription
> settings from http://www.ceramics.org/clayart/
>
> Moderator of the list is Mel Jacobson who may be reached at melpots@pclink.com.
>
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Gregory D Lamont on fri 17 nov 00
Hi Anne,
You don't mention in your post if the ends of your kilm posts were dipped
in kiln wash. At the university where I recently studied ceramics, the
prof insisted this be done. Periodically, the old kiln wash needed to be
sanded from the ends of the posts and new applied, but thats about it. I
never saw them stick either to shelves or softbrick.
Greg
At 12:00 AM 11/17/00 -0500, you wrote:
>Date: Wed, 15 Nov 2000 22:45:37 -0800
>From: Anne Hunt
>Subject: Kiln Floor Soft Brick Sticking to Posts
>
>'Lo, all:
> Well, a new wrinkle on the learning curve of firing the Big Dog (24cf
>propane kiln), is that the posts sitting on the floor of the kiln come away
>with chunks of the soft brick attached. I don't mind sanding off the soft
>brick, but am not real crazy about losing part of the kiln floor.
> I only truly noticed it after the last ^10 firing, when I
> inadvertantly got
>up to ^11 or so. I usually stack three shelves high, and fire somewhat
>heavy pieces. Is this abnormal, or due to the weight?
> Would putting more posts under the first shelf help distribute
> the weight
>more? Should I coat the floor with Sairset/kiln patch?
> Did it mebbe happen 'cause I went too high on the last firing?
> i really don't like having holes/pitting in the floor, so some
> advice would
>be greatly appreciated.
>
>TIA,
>
>anne & the cats, in Sequim, where the night frost covers everything with
>tiny diamonds. Now if only I could see the sun breaking through an Alaskan
>ice fog....more wondrous than the sound of F-15 Jet Fuel Starters cranking
>up for the morning "goes". Sigh.
Earl Brunner on sat 18 nov 00
I have never fired a kiln that didn't have shelves as the
floor of the kiln to protect the brick (especially the soft
brick) or used as the floor of the kiln.
> >Subject: Kiln Floor Soft Brick Sticking to Posts
> >
> >'Lo, all:
> > Well, a new wrinkle on the learning curve of firing the Big Dog (24cf
> >propane kiln), is that the posts sitting on the floor of the kiln come away
> >with chunks of the soft brick attached. I don't mind sanding off the soft
> >brick, but am not real crazy about losing part of the kiln floor.
> > I only truly noticed it after the last ^10 firing, when I
> > inadvertantly got
> >up to ^11 or so. I usually stack three shelves high, and fire somewhat
> >heavy pieces. Is this abnormal, or due to the weight?
> > Would putting more posts under the first shelf help distribute
> > the weight
> >more? Should I coat the floor with Sairset/kiln patch?
> > Did it mebbe happen 'cause I went too high on the last firing?
> > i really don't like having holes/pitting in the floor, so some
> > advice would
> >be greatly appreciated.
> >
> >TIA,
> >
> >anne & the cats, in Sequim, where the night frost covers everything with
> >tiny diamonds. Now if only I could see the sun breaking through an Alaskan
> >ice fog....more wondrous than the sound of F-15 Jet Fuel Starters cranking
> >up for the morning "goes". Sigh.
>
> ______________________________________________________________________________
> Send postings to clayart@lsv.ceramics.org
>
> You may look at the archives for the list or change your subscription
> settings from http://www.ceramics.org/clayart/
>
> Moderator of the list is Mel Jacobson who may be reached at melpots@pclink.com.
--
Earl Brunner
http://coyote.accessnv.com/bruec
mailto:bruec@anv.net
John Baymore on thu 23 nov 00
Well, a new wrinkle on the learning curve of firing the Big Dog
(24cf
propane kiln), is that the posts sitting on the floor of the kiln come aw=
ay
with chunks of the soft brick attached. I don't mind sanding off the sof=
t
brick, but am not real crazy about losing part of the kiln floor.
Anne,
With a larger kiln, the stacking of ware, stilts, and shelves weighs a lo=
t.
All of the weight is concentrated on the three stilts that carry the bun=
g
of shelves. The end of a typical stilt is only a few square inches of
surface. This ends up as a lot of "crushing" force per square foot on th=
e
soft insulaling firebrick. This will, over time, then to erode the hot
face of the floor where the stilts contact it. If you can spread out th=
is
force over a larger surface area you can decrease the damage you will be
doing over time to the floor of the kiln.
When I build kilns the inner working surface of the floor where the shelv=
es
are stacked is always a thin layer of hard refractory brick to resist thi=
s
type of deterioration (along with helping to resist the occasional chips =
of
glaze and drips of junk that tend to end up there ).
Since you don't want to raise the floor too much and lose useful space or=
affect the chamber proportions....... maybe use a couple of kiln shelves =
to
dissipate the weight on the soft brick floor.
Also...if you used most brands of 2300 F rated IF brick ..... and are
firing to cone 11 in reduction, you are pushing the refractory use rating=
hard. So that may be contributing to the sticking factor. Also..... if
the stilts you are using are old......look a the ends of the stilts. Hav=
e
they accumulated some tiny bits of glaze on them?
Just a couple of thoughts.
BEst,
..........................john
John Baymore
River Bend Pottery
22 Riverbend Way
Wilton, NH 03086 USA
603-654-2752 (s)
800-900-1110 (s)
JBaymore@compuserve.com
John.Baymore@GSD-CO.com
"DATES SET: Earth, Water, and Fire Noborigama Woodfiring Workshop =
August 17-26, 2001"
=
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