sdpotter@GTE.NET on thu 8 jun 00
Jeff,
This is from Alistair Young's "Setting up a Pottery Workshop."
Fireclay 4
Sawdust 4 (fine to chippings)
Grog 4 (dust to 5mm)
Cement 1
Alumina 1(for salt or soda)
Parts by volume
Steve
----------
> From: Jeff & Melanie Boock
> To: CLAYART@LSV.CERAMICS.ORG
> Subject: Castable for Salt Kiln
> Date: Sat, 17 Jun 2000 13:18:50 -0600
>
>I am looking for a good castable formula for constructing a door for
>a salt kiln I am almost finished building. I would like to cast the
>door in 4 pieces. I would also like to use this same castable to
>patch some small gaps in my brickwork between the back wall and the
>arch.
>
>Any suggestions?
>
>Thanks!
>
>Jeff Boock
>jeff@boock.com
>
>___________________________________________________________________________
___
>Send postings to clayart@lsv.ceramics.org
>
>You may look at the archives for the list or change your subscription
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>
>Moderator of the list is Mel Jacobson who may be reached at
melpots@pclink.com.
lucien m koonce on thu 8 jun 00
Hi Jeff,
This information is a bit old, and may have been improved upon over the
years: Studio Potter, Summer 1975 issue, has articles on castable
refractories and the salt kiln, by Tom Turner, Wally Smith, and Richard
Leach.
Lucien
Koonce
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Click on http://lmkoonce.home.mindspring.com and visit my on-line gallery.
L M Koonce / Robbins, NC, USA
-----Original Message-----
From: Jeff & Melanie Boock
To: CLAYART@LSV.CERAMICS.ORG
Date: Thursday, June 08, 2000 12:24 PM
Subject: Castable for Salt Kiln
>I am looking for a good castable formula for constructing a door for
>a salt kiln I am almost finished building. I would like to cast the
>door in 4 pieces. I would also like to use this same castable to
>patch some small gaps in my brickwork between the back wall and the
>arch.
>
>Any suggestions?
>
>Thanks!
>
>Jeff Boock
>jeff@boock.com
>
>___________________________________________________________________________
___
>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.
Jim Bozeman on thu 8 jun 00
Hey Jeff, Let me know what you find out. I'm in the same boat. Jim
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iandol on fri 9 jun 00
Jeff,=20
I suggest you try to get hold of Jack Troy=92s Book , Salt Glaze =
Ceramics. I have made a castable using a high alumina Kaolin which was =
cheaper than fireclay, mixed equal parts with alumina sand as a grog, =
Primed with about 5 percent white cement to act as a binder and loaded =
with sawdust to improve insulation. About 5percent by weight gives about =
30-40% volume. For removable tiles for a top loading salt kiln I =
substituted vermiculite for saw dust. Bricks and tiles were fired to =
Orton cone 8 to cure them prior to use.
Keeping the alumina as high as possible increases the life and =
resistance to salt. Soda firings should not corrode refractories.
Have fun
Ivor. In S Oz on a rainy day
Dave Finkelnburg on sat 10 jun 00
Hi Ivor!
Can you explain what you mean by "alumina sand?" I am familiar with
alumina hydrate here, but not sure what you are referring to. I suspect it
is a coarsly ground alumina. Is that correct? If so, can you give me an
idea of the size distribution? Thanks! I hope the winter there is
treating you well!
Dave Finkelnburg, happily in the studio and out of today's Idaho
thunderstorms
From: iandol
You wrote: "I have made a castable using a high alumina Kaolin which was
cheaper than fireclay, mixed equal parts with alumina sand as a grog, Primed
with about 5 percent white cement to act as a binder and loaded with sawdust
to improve insulation. About 5percent by weight gives about 30-40% volume.
For removable tiles for a top loading salt kiln I substituted vermiculite
for saw dust. Bricks and tiles were fired to Orton cone 8 to cure them prior
to use.
Keeping the alumina as high as possible increases the life and resistance to
salt. Soda firings should not corrode refractories."
Craig Martell on sun 11 jun 00
Hi:
If you can afford to buy a premixed castable, I recommend Missou Castable
from AP Green. It's 70% alumina and works very well. I used this to make
the firebox troughs in my salt kiln and am very pleased with it's performance.
Craig Martell in Oregon
John Baymore on mon 12 jun 00
(clip)
If you can afford to buy a premixed castable, I recommend Missou Castable=
from AP Green. It's 70% alumina and works very well. I used this to mak=
e
the firebox troughs in my salt kiln and am very pleased with it's
performance.
(snip)
Gotta agree strongly with Craig on this. I have used Mizzou castable (an=
d
Mizzou brick) for decades when doing designs for salt firing. It stands =
up
well to the slagging attack. It is also great for certain areas of the
fireboxes / throats of wood kilns ....for the same reason. In some
situations, I will verneer it onto the hot face side with other higher
insulating materials on the cold face behind it. When the hot face surfa=
ce
finally degrades to the point of needing replacing, the verneer is broken=
up and removed, and then replaced with a new hot face surface, leaving th=
e
main structural backup wall intact. (I typically don't use it less than
two inches thick in this application.)
There is one thought on this castable thread that Craig sort of alludes t=
o
above .............. the "if you can afford..." comment, that I'd like to=
address a bit. My guess from the wording above is that he is recommendin=
g
that you DO try to afford it . I often see the word "cheap" attached =
to
searches for materials by potters. I can't remember if it was anywhere o=
n
the early part of this thread.....but I think it was. "Cheap" is a two
edged sword.
Quite often in the pursuit of "cheap", some potters tend to make short te=
rm
CHEAP decisions that are long term EXPENSIVE decisions. A "cheap"
castable now can often result in more frequent kiln replacement / down ti=
me
/ firing defects that show up later. That is a REAL cost of the cheap
castable (or other material) that can be a hidden cost that isn't
considered at the construction time. Also, the labor used to rebuild the=
kiln more often than necessary is another real hidden cost...... your tim=
e
is worth money.
It is certainly fun to make homemade castables and bricks and build kilns=
out of them. And a valuable learning experience. But don't generally
expect these homemade variations to stand up to heavy use and time like
their commercial counterparts. If longevity, durability, and high
performance are criteria for the design of a kiln, it is hard to beat
commercial grade refractories. No....they're not cheap.....but they get
the job done. There is a reason that these professional companies make
this kind of stuff and that industry then uses it, not homemade stuff >.
=
The more experience you have in ceramic chemistry and kiln building, the
better the likelyhood that a homemade material you will come up with and
fabricate on site will preform well in the long term. Sort of like any
other aspect of ceramics..... the more you know the better you tend to do=
.
So..... I think a potter might want to be careful in evaluating
construction materials when building kilns. Sometimes the most expensive=
material to buy now is actually the cheapest material to use in the long
run.
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
"Earth, Water, and Fire Noborigama Woodfiring Workshop August 18-27,
2000"
Jeff & Melanie Boock on sat 17 jun 00
I am looking for a good castable formula for constructing a door for
a salt kiln I am almost finished building. I would like to cast the
door in 4 pieces. I would also like to use this same castable to
patch some small gaps in my brickwork between the back wall and the
arch.
Any suggestions?
Thanks!
Jeff Boock
jeff@boock.com
John Baymore on sat 17 jun 00
(clip)
If you can afford to buy a premixed castable, I recommend Missou Castable=
from AP Green. It's 70% alumina and works very well. I used this to mak=
e
the firebox troughs in my salt kiln and am very pleased with it's
performance.
(snip)
Gotta agree strongly with Craig on this. I have used Mizzou castable (an=
d
Mizzou brick) for decades when doing designs for salt firing. It stands =
up
well to the slagging attack. It is also great for certain areas of the
fireboxes / throats of wood kilns ....for the same reason. In some
situations, I will verneer it onto the hot face side with other higher
insulating materials on the cold face behind it. When the hot face surfa=
ce
finally degrades to the point of needing replacing, the verneer is broken=
up and removed, and then replaced with a new hot face surface, leaving th=
e
main structural backup wall intact. (I typically don't use it less than
two inches thick in this application.)
There is one thought on this castable thread that Craig sort of alludes t=
o
above .............. the "if you can afford..." comment, that I'd like to=
address a bit. My guess from the wording above is that he is recommendin=
g
that you DO try to afford it . I often see the word "cheap" attached =
to
searches for materials by potters. I can't remember if it was anywhere o=
n
the early part of this thread.....but I think it was. "Cheap" is a two
edged sword.
Quite often in the pursuit of "cheap", some potters tend to make short te=
rm
CHEAP decisions that are long term EXPENSIVE decisions. A "cheap"
castable now can often result in more frequent kiln replacement / down ti=
me
/ firing defects that show up later. That is a REAL cost of the cheap
castable (or other material) that can be a hidden cost that isn't
considered at the construction time. Also, the labor used to rebuild the=
kiln more often than necessary is another real hidden cost...... your tim=
e
is worth money.
It is certainly fun to make homemade castables and bricks and build kilns=
out of them. And a valuable learning experience. But don't generally
expect these homemade variations to stand up to heavy use and time like
their commercial counterparts. If longevity, durability, and high
performance are criteria for the design of a kiln, it is hard to beat
commercial grade refractories. No....they're not cheap.....but they get
the job done. There is a reason that these professional companies make
this kind of stuff and that industry then uses it, not homemade stuff >.
=
The more experience you have in ceramic chemistry and kiln building, the
better the likelyhood that a homemade material you will come up with and
fabricate on site will preform well in the long term. Sort of like any
other aspect of ceramics..... the more you know the better you tend to do=
.
So..... I think a potter might want to be careful in evaluating
construction materials when building kilns. Sometimes the most expensive=
material to buy now is actually the cheapest material to use in the long
run.
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
"Earth, Water, and Fire Noborigama Woodfiring Workshop August 18-27,
2000"
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