jonathan byler on wed 26 may 10
I just wanted to share with people the castable recipe that we used on
top of our new soda kiln, in case that someone else can make use of
this information. it was a good way to insulate above the hardbrick
arch with minimal expense and effort, and so far has produced good
results. we used a mixture as follows:
40% fireclay
40% sand
10% portland cement
to this we added enough sodium silicate and water to make the make the
mix moist enough to apply and finish with a trowel. for inuslation we
then added crushed up fire brick (we have a few barrels of broken old
bricks) that was a variety of sizes (graded aggregate) no larger than
about 1-1/2 to 2 inches in diameter for the largest pieces.
Looking back We probably should have added saw dust in an amount
between 25% and 50% for extra insulating and to help with dry strength.
This mixture was applied to the top of the arch in an even layer about
4 inches thick. it was very workable with a trowel, much like
finishing very stiff concrete. You can shake it a bit like when
working with concrete to get the aggregate to settle a bit and get a
nice looking surface. as it dried we had about 3 major cracks form
along the length of the arch. next time I do this I am going to pre
cut cracks or form them in place to make the inevitable cracks more
uniform, but this is only a matter of looks. It dried within a day to
a surface that was strong enough to stand on, although it still would
leave marks, and was definitely not water proof.
If we had laid a layer of fiber insulation between the castable and
the hardbrick arch, I think it would have given even greater insulation.
Despite this I was able to put my hand on top of the kiln still after
it had reached ^6 for almost as long as on the sides of the kiln which
are hard brick with a soft brick shell outside. putting my hand near/
on the hard bricks that tie the two wall courses together gave a good
indication of how much insulating we were getting out of the castable
and the soft bricks.
We only got to ^6 because the blowers I had on the burners were
underpowered, and the door was only bricked up 4.5 inches thick with
softbrick. I figured this was good enough for now, since I was only
trying to cook out any water in the mortar joints and the castable
arch, and also giving the nitride bonded shelves an initial firing.
much to my surprise, I ran into a problem discussed recently about the
bottom of a downdraught kiln being hotter than the top. we
essentially have no bagwall, and the castable above the arch was still
giving off steam for much of the firing, so I figured both of these
were contributing to the problem. Despite these troubles, I was able
to bring this kiln up to ^6 in about 6.5 hours time. with the more
powerful blowers and a course of bricks on their side for a bagwall
installed I think this thing is going to fire very nicely - the kiln
god I put in seemed to be doing its job, and apparently my amateur
kiln design skills are working out too. Hopefully we will have our
initial firing with ware and soda next week.
-jon
douglas fur on sat 29 may 10
Jon
Thanks for the post. No politics or philosophy just the facts
DRB
Burien
On Wed, May 26, 2010 at 9:14 PM, jonathan byler wrote:
> I just wanted to share with people the castable recipe that we used on
> top of our new soda kiln, in case that someone else can make use of
> this information. it was a good way to insulate above the hardbrick
> arch with minimal expense and effort, and so far has produced good
> results. we used a mixture as follows:
>
> 40% fireclay
> 40% sand
> 10% portland cement
>
> to this we added enough sodium silicate and water to make the make the
> mix moist enough to apply and finish with a trowel. for inuslation we
> then added crushed up fire brick (we have a few barrels of broken old
> bricks) that was a variety of sizes (graded aggregate) no larger than
> about 1-1/2 to 2 inches in diameter for the largest pieces.
>
> Looking back We probably should have added saw dust in an amount
> between 25% and 50% for extra insulating and to help with dry strength.
>
> This mixture was applied to the top of the arch in an even layer about
> 4 inches thick. it was very workable with a trowel, much like
> finishing very stiff concrete. You can shake it a bit like when
> working with concrete to get the aggregate to settle a bit and get a
> nice looking surface. as it dried we had about 3 major cracks form
> along the length of the arch. next time I do this I am going to pre
> cut cracks or form them in place to make the inevitable cracks more
> uniform, but this is only a matter of looks. It dried within a day to
> a surface that was strong enough to stand on, although it still would
> leave marks, and was definitely not water proof.
>
> If we had laid a layer of fiber insulation between the castable and
> the hardbrick arch, I think it would have given even greater insulation.
> Despite this I was able to put my hand on top of the kiln still after
> it had reached ^6 for almost as long as on the sides of the kiln which
> are hard brick with a soft brick shell outside. putting my hand near/
> on the hard bricks that tie the two wall courses together gave a good
> indication of how much insulating we were getting out of the castable
> and the soft bricks.
>
> We only got to ^6 because the blowers I had on the burners were
> underpowered, and the door was only bricked up 4.5 inches thick with
> softbrick. I figured this was good enough for now, since I was only
> trying to cook out any water in the mortar joints and the castable
> arch, and also giving the nitride bonded shelves an initial firing.
>
> much to my surprise, I ran into a problem discussed recently about the
> bottom of a downdraught kiln being hotter than the top. we
> essentially have no bagwall, and the castable above the arch was still
> giving off steam for much of the firing, so I figured both of these
> were contributing to the problem. Despite these troubles, I was able
> to bring this kiln up to ^6 in about 6.5 hours time. with the more
> powerful blowers and a course of bricks on their side for a bagwall
> installed I think this thing is going to fire very nicely - the kiln
> god I put in seemed to be doing its job, and apparently my amateur
> kiln design skills are working out too. Hopefully we will have our
> initial firing with ware and soda next week.
>
> -jon
>
Mark Archer on tue 8 jun 10
Jon,
Try paper pulp instead of sawdust it is cheaper, lighter and a better ins=
=3D
ulator than sawdust.=3D20
As for the steaming wet top: Ancient potters have fired successfully in e=
=3D
xtremely cold and wet=3D20
environments: the problem of your uneven firing most likely has more to d=
=3D
o with the=3D20
relationship between your primary intake, the height of your bag-wall, fl=
=3D
ue/damper setting and=3D20
even the speed at which you fire (not to mention the fuel, which you leav=
=3D
e unstated), all of=3D20
which are exceedingly more relevant to how even or uneven your kiln fires=
=3D
, than the fact that it=3D20
is, or is not steaming at its top like a wet tea kettle.
Raise the bag-wall. Slow down the rate of climb. Soak it for a while. Ins=
=3D
ulate/cast a kiln with a=3D20
paper, clay, sand mixture.
Safety first. That's my advice.=3D20
Mark Archer
Ron Roy on tue 8 jun 10
Hi Paul,
I think diatomaceeous earth may be one of those materials that can
cause silicosis - it will not be hard to check out.
RR
Quoting Paul Herman :
> Hello All,
>
> Another good insulation material is diatomaceous earth, which we use
> in our insulating mud. I get it at the auto parts store where it is
> sold as grease absorbent. I don't know if it is available back east,
> but it's a great natural mineral insulation. They made the first
> insulating firebrick from diatomaceous earth I believe.
>
> best,
>
> Paul Herman
>
> Great Basin Pottery
> Doyle, California US
> www.greatbasinpottery.com/
>
>
>
>
> On Jun 8, 2010, at 12:24 PM, jonathan byler wrote:
>
>> Hi Mark,
>>
>> Thanks for the suggestion of the paper pulp. we have a ready supply
>> of free sawdust on hand already, but I will give the paper a try next
>> time we do this. Are you suggesting shredded paper like from an
>> office paper shredder, or actual pulp like you would have to make
>> paper?
>
Linda Stauffer on tue 8 jun 10
Diatomaceous earth is available at any pool supply store. It is the =3D
stuff used in pool filters
On Jun 8, 2010, at 5:22 PM, Paul Herman wrote:
> Hello All,
>=3D20
> Another good insulation material is diatomaceous earth, which we use
> in our insulating mud. I get it at the auto parts store where it is
> sold as grease absorbent. I don't know if it is available back east,
> but it's a great natural mineral insulation. They made the first
> insulating firebrick from diatomaceous earth I believe.
>=3D20
> best,
>=3D20
> Paul Herman
>=3D20
> Great Basin Pottery
> Doyle, California US
> www.greatbasinpottery.com/
>=3D20
>=3D20
>=3D20
>=3D20
> On Jun 8, 2010, at 12:24 PM, jonathan byler wrote:
>=3D20
>> Hi Mark,
>>=3D20
>> Thanks for the suggestion of the paper pulp. we have a ready supply
>> of free sawdust on hand already, but I will give the paper a try next
>> time we do this. Are you suggesting shredded paper like from an
>> office paper shredder, or actual pulp like you would have to make
>> paper?
Robert Harris on tue 8 jun 10
Not bad for dynamite either!
jonathan byler on tue 8 jun 10
Hi Mark,
Thanks for the suggestion of the paper pulp. we have a ready supply
of free sawdust on hand already, but I will give the paper a try next
time we do this. Are you suggesting shredded paper like from an
office paper shredder, or actual pulp like you would have to make paper?
as to the uneven temps, I discovered that the blowers that I was using
were not strong enough, so I got some more powerful ones and things
seem to work better now. I raised up the bagwall by about 4.5" and
adjusted how the target brick sits too. I also took some time to look
at the flame length at various air/fuel settings. we are doing our
first real firing of the kiln with ware and soda tomorrow or the next
day, so hopefully the changes work well.
On Jun 8, 2010, at 1:30 AM, Mark Archer wrote:
> Jon,
> Try paper pulp instead of sawdust it is cheaper, lighter and a
> better insulator than sawdust.
>
> As for the steaming wet top: Ancient potters have fired successfully
> in extremely cold and wet
> environments: the problem of your uneven firing most likely has more
> to do with the
> relationship between your primary intake, the height of your bag-
> wall, flue/damper setting and
> even the speed at which you fire (not to mention the fuel, which you
> leave unstated), all of
> which are exceedingly more relevant to how even or uneven your kiln
> fires, than the fact that it
> is, or is not steaming at its top like a wet tea kettle.
> Raise the bag-wall. Slow down the rate of climb. Soak it for a
> while. Insulate/cast a kiln with a
> paper, clay, sand mixture.
> Safety first. That's my advice.
> Mark Archer
Paul Herman on tue 8 jun 10
Hello All,
Another good insulation material is diatomaceous earth, which we use
in our insulating mud. I get it at the auto parts store where it is
sold as grease absorbent. I don't know if it is available back east,
but it's a great natural mineral insulation. They made the first
insulating firebrick from diatomaceous earth I believe.
best,
Paul Herman
Great Basin Pottery
Doyle, California US
www.greatbasinpottery.com/
On Jun 8, 2010, at 12:24 PM, jonathan byler wrote:
> Hi Mark,
>
> Thanks for the suggestion of the paper pulp. we have a ready supply
> of free sawdust on hand already, but I will give the paper a try next
> time we do this. Are you suggesting shredded paper like from an
> office paper shredder, or actual pulp like you would have to make
> paper?
David Woof on wed 9 jun 10
Really good insulator=3D2C economical....used with success for over 30 year=
s =3D
of kiln building.
=3D20
For each cement mixer load
=3D20
Add/Mix in the following order for good reasons.....
=3D20
5 gal water
=3D20
1 rounded shovel scoop Portland cement
=3D20
1 5 gal pail 16 grit silica sand (local contractors supply). Grit size =
=3D
is important to keep the mixer self cleaning and unclogged
=3D20
1/2 5 gal pail of ball or fire clay
=3D20
1 5 gal pail local adobe clay/dirt
=3D20
1.5 5 gal pail med/coarse sawdust
=3D20
a bit more water (to taste) if needed for mud/ram consistency
_________________________________________________Happy Mudding =3D20
=3D20
I've also applyed this over a layer of IFB scraps and pieces.
=3D20
Some folks apply bricks or castable over a layer of refractory fiber but lo=
=3D
se some the fiber's insulating quality due to the crush factor.
David Woof =3D20
=3D20
_________________________________________________________________
The New Busy is not the old busy. Search=3D2C chat and e-mail from your inb=
ox=3D
.
http://www.windowslive.com/campaign/thenewbusy?ocid=3D3DPID28326::T:WLMTAGL=
:O=3D
N:WL:en-US:WM_HMP:042010_3=3D
Paul Herman on wed 9 jun 10
Hi Linda, Robert and Ron,
Linda, I think the stuff they use for pool filters is pretty finely
ground, and I'm not sure it's as good an insulation as the more chunky
stuff. The grease absorbent comes in "fine" (about 16 mesh) and
"coarse", (about 4-6 mesh.)
Robert, I was not aware they used it in dynamite making, though seem
to remember some kind of clay being used.
Ron, diatomaceous earth (DE) is more than 90% opaline silica, from the
skeletons of the little diatoms, so yes you would certainly show the
same caution that you would use with any dry silica containing
material. From what I've read, some DE products are calcined, which
converts some of the silica to cristobalite and makes it more
dangerous to breathe. I think the grease absorbent is raw. When we
make up a batch of insulating mud for the kiln, we do it outside and
try not to breath any of the dust. After wetting it and spreading it
onto the kiln, it is no longer airborne, and no longer a threat.
From it's density and insulating qualities, the insulating mud seems
to have about the same R value as K23 soft brick.
Good firings,
Paul Herman
Great Basin Pottery
Doyle, California US
www.greatbasinpottery.com/
On Jun 8, 2010, at 5:04 PM, Linda Stauffer wrote:
> Diatomaceous earth is available at any pool supply store. It is the
> stuff used in pool filters
> On Jun 8, 2010, at 5:22 PM, Paul Herman wrote:
>
>> Hello All,
>>
>> Another good insulation material is diatomaceous earth, which we use
>> in our insulating mud. I get it at the auto parts store where it is
>> sold as grease absorbent. I don't know if it is available back east,
>> but it's a great natural mineral insulation. They made the first
>> insulating firebrick from diatomaceous earth I believe.
>>
>> best,
>>
>> Paul Herman
>>
>> Great Basin Pottery
>> Doyle, California US
>> www.greatbasinpottery.com/
>>
>>
>>
>>
>> On Jun 8, 2010, at 12:24 PM, jonathan byler wrote:
>>
>>> Hi Mark,
>>>
>>> Thanks for the suggestion of the paper pulp. we have a ready supply
>>> of free sawdust on hand already, but I will give the paper a try
>>> next
>>> time we do this. Are you suggesting shredded paper like from an
>>> office paper shredder, or actual pulp like you would have to make
>>> paper?
Edouard Bastarache on wed 9 jun 10
Diatomaceous Earth Toxicology
By Edouard Bastarache
-------------------------------------------------------------------------=
=3D
-------
Synonyms :=3D20
=3D20
Diatomite, diatomaceous silica, infusorial earth.=3D20
=3D20
Uses :=3D20
=3D20
In the production of filters, polishes, absorbents, insulators.=3D20
=3D20
Toxicity :=3D20
=3D20
Amorphous silica, natural diatomaceous earth, is usually considered to =3D
be of low toxicity; however, pure amorphous silica is rarely found. =3D
Depending on the source, it may contain a low percentage of =3D
contaminating quartz, rarely over 2%; characteristically, natural =3D
diatomite contains no measurable cristobalite.=3D20
Processing of amorphous silica by high-temperature calcining, with or =3D
without the concomitant use of fluxing agents, alters the silica from =3D
the benign amorphous to the pathogenic form (cristobalite), which causes =
=3D
lung fibrosis.=3D20
Non-flux-calcined diatomite may contain from 20% to 30% cristobalite, =3D
flux-calcined diatomite may contain as much as 60% cristobalite. =3D
Calcined diatomite can produce a severe and disabling pneumoconiose, =3D
which is attributed to its cristobalite content. Altough a form of =3D
silicosis, it characteristically produces pathologic and radiographic =3D
changes, which are different from classical quartz silicosis. Diffuse =3D
rather than nodular changes are more common.=3D20
There is no evidence to associate any form of diatomaceous earth with =3D
human cancer.=3D20
The IARC concluded that evidence is inadequate to describe amorphous =3D
silica as carcinogenic in either experimental animals or humans. The =3D
IARC concluded that crystalline silica is a probable human carcinogen.=3D20
=3D20
Quebec's exposure limit :=3D20
=3D20
VEMP (Valeur d'Exposition Moyenne Pond=3DE9r=3DE9e) =3D3D 6 mg/m=3DB3 (Tota=
l =3D
dust), if the crystalline silica content is < 1%=3D20
=3D20
=3D20
References :=3D20
1-Occupational Medicine,Carl Zenz, last edition.=3D20
2-Clinical Environmental Health and Toxic Exposures, Sullivan & Krieger; =
=3D
last edition.=3D20
3-Sax's Dangerous Properties of Industrial Materials, Lewis C., last =3D
edition.=3D20
4-Toxicologie Industrielle et Intoxications Professionnelles, Lauwerys =3D
R.R. last edition.=3D20
5-Chemical Hazards of the Workplace, Proctor & Hughes, 4th edition=3D20
=3D20
Gis,
Edouard Bastarache=3D20
Spertesperantisto=3D20
Sorel-Tracy
Quebec
http://www.flickr.com/photos/30058682@N00/
http://edouardbastarache.blogspot.com/
http://blogsalbertbastarache.blogspot.com/
http://cerampeintures.blogspot.com/
http://perso.wanadoo.fr/smart2000/index.htm
=3D20
L TURNER on wed 9 jun 10
Ron,
et. al.,
according to wikipedia: http://en.wikipedia.org/wiki/Diatomaceous_earth
"The typical chemical composition of oven dried diatomaceous earth is
80 to 90% silica, with 2 to 4% alumina (attributed mostly to clay
minerals) and 0.5 to 2% iron oxide."
So basically adding diatomaceous earth to a ceramic mix is the same as
adding silica. The primary difference will be particle size
distribution.
Regards,
Lou Turner
The Woodlands, TX
David Woof on thu 10 jun 10
Warning!!! Aviso!!! Achtung!!!.......
=3D20
Just to be sure no one misunderstands: My recipe is for insulating a cast =
=3D
or brick arch as a top coating of insulation only.
=3D20
Sorry if I wasn't clear enough.
=3D20
David Woof
=3D20
=3D20
=3D20
________________________________________________________________________
9a. Re: castable material for arch insulation/new soda kiln info
Posted by: "David Woof" woofpots@HOTMAIL.COM=3D20
Date: Thu Jun 10=3D2C 2010 9:15 am ((PDT))
=3D20
Really good insulator=3D2C economical....used with success for over 30 year=
s =3D
of kiln building.
=3D20
=3D20
=3D20
For each cement mixer load
=3D20
=3D20
=3D20
Add/Mix in the following order for good reasons.....
=3D20
=3D20
=3D20
5 gal water
=3D20
=3D20
=3D20
1 rounded shovel scoop Portland cement
=3D20
=3D20
=3D20
1 5 gal pail 16 grit silica sand (local contractors supply). Grit size is i=
=3D
mportant to keep the mixer self cleaning and unclogged
=3D20
=3D20
=3D20
1/2 5 gal pail of ball or fire clay
=3D20
=3D20
=3D20
1 5 gal pail local adobe clay/dirt
=3D20
=3D20
=3D20
1.5 5 gal pail med/coarse sawdust
=3D20
=3D20
=3D20
a bit more water (to taste) if needed for mud/ram consistency
=3D20
_________________________________________________Happy Mudding=3D20
=3D20
=3D20
=3D20
I've also applyed this over a layer of IFB scraps and pieces.
=3D20
=3D20
=3D20
Some folks apply bricks or castable over a layer of refractory fiber but lo=
=3D
se some the fiber's insulating quality due to the crush factor.
=3D20
=3D20
David Woof=3D20
=3D20
=3D20
=3D20
_________________________________________________________________
The New Busy think 9 to 5 is a cute idea. Combine multiple calendars with H=
=3D
otmail.=3D20
http://www.windowslive.com/campaign/thenewbusy?tile=3D3Dmulticalendar&ocid=
=3D3D=3D
PID28326::T:WLMTAGL:ON:WL:en-US:WM_HMP:042010_5=3D
tony clennell on thu 10 jun 10
To David's castable I would paint or preferably spray this Working
Potters ITC formula . I wrote Working mans and quickly corrected
myself. I'm learnin'! I put this over the castable in my throat arch-
a place that takes a real beating. Al Tennant has also used it on his
train kiln and the one he built for Amy Kiline at Pottery West. He
swears by it. If you know Al he swears most of the time.
Coating
2 parts Alumina Hydrate
2 parts 35 mesh Kyanite
2 parts Zirconium (Zircopax, Opax or whatever) this is the expensive part
1 part Vee gum T
I use weight and not volume
Bon feu!
Tony
On Thu, Jun 10, 2010 at 1:32 AM, David Woof wrote:
> Really good insulator, economical....used with success for over 30 years =
of kiln building.
>
>
>
> For each cement mixer load
>
>
>
> Add/Mix in the following order for good reasons.....
>
>
>
> 5 gal water
>
>
>
> 1 rounded shovel scoop Portland cement
>
>
>
> 1 5 gal pail 16 grit silica sand (local contractors supply). Grit siz=
e is important to keep the mixer self cleaning and unclogged
>
>
>
> 1/2 5 gal pail of ball or fire clay
>
>
>
> 1 5 gal pail local adobe clay/dirt
>
>
>
> 1.5 5 gal pail med/coarse sawdust
>
>
>
> a bit more water (to taste) if needed for mud/ram consistency
>
> _________________________________________________Happy Mudding
>
>
>
> I've also applyed this over a layer of IFB scraps and pieces.
>
>
>
> Some folks apply bricks or castable over a layer of refractory fiber but =
lose some the fiber's insulating quality due to the crush factor.
>
>
> David Woof
>
>
>
>
> _________________________________________________________________
> The New Busy is not the old busy. Search, chat and e-mail from your inbox=
.
> http://www.windowslive.com/campaign/thenewbusy?ocid=3DPID28326::T:WLMTAGL=
:ON:WL:en-US:WM_HMP:042010_3
--
http://sourcherrypottery.com
http://smokieclennell.blogspot.com
tony clennell on fri 11 jun 10
David: thanx for the clarification.
tc
On Thu, Jun 10, 2010 at 9:51 PM, David Woof wrote:
> Warning!!! Aviso!!! Achtung!!!.......
>
>
>
> Just to be sure no one misunderstands: My recipe is for insulating a cas=
t or brick arch as a top coating of insulation only.
>
>
>
> Sorry if I wasn't clear enough.
>
>
>
> David Woof
>
>
>
>
>
>
>
> ________________________________________________________________________
> 9a. Re: castable material for arch insulation/new soda kiln info
> Posted by: "David Woof" woofpots@HOTMAIL.COM
> Date: Thu Jun 10, 2010 9:15 am ((PDT))
>
> Really good insulator, economical....used with success for over 30 years =
of kiln building.
>
>
>
> For each cement mixer load
>
>
>
> Add/Mix in the following order for good reasons.....
>
>
>
> 5 gal water
>
>
>
> 1 rounded shovel scoop Portland cement
>
>
>
> 1 5 gal pail 16 grit silica sand (local contractors supply). Grit size is=
important to keep the mixer self cleaning and unclogged
>
>
>
> 1/2 5 gal pail of ball or fire clay
>
>
>
> 1 5 gal pail local adobe clay/dirt
>
>
>
> 1.5 5 gal pail med/coarse sawdust
>
>
>
> a bit more water (to taste) if needed for mud/ram consistency
>
> _________________________________________________Happy Mudding
>
>
>
> I've also applyed this over a layer of IFB scraps and pieces.
>
>
>
> Some folks apply bricks or castable over a layer of refractory fiber but =
lose some the fiber's insulating quality due to the crush factor.
>
>
> David Woof
>
>
>
>
>
>
>
> _________________________________________________________________
> The New Busy think 9 to 5 is a cute idea. Combine multiple calendars with=
Hotmail.
> http://www.windowslive.com/campaign/thenewbusy?tile=3Dmulticalendar&ocid=
=3DPID28326::T:WLMTAGL:ON:WL:en-US:WM_HMP:042010_5
--
http://sourcherrypottery.com
http://smokieclennell.blogspot.com
jonathan byler on fri 11 jun 10
Tony,
my understanding is the ITC is made up by mixing zirconia flour with
colloidal silica. have you tried this yet? I have been looking to
get ahold of some colloidal silica (fumed silica suspended in water)
for making castable anyway. colloidal silica is supposed to be an
excellent bonding and suspension agent and doesn't pose the same
problems that portland cement does in castable formulas. my
understanding is that the colloidal silica helps keep the ITC in
suspension in addition to helping it bond before it is fired.
best,
jon byler
On Jun 10, 2010, at 3:05 PM, tony clennell wrote:
> To David's castable I would paint or preferably spray this Working
> Potters ITC formula . I wrote Working mans and quickly corrected
> myself. I'm learnin'! I put this over the castable in my throat arch-
> a place that takes a real beating. Al Tennant has also used it on his
> train kiln and the one he built for Amy Kiline at Pottery West. He
> swears by it. If you know Al he swears most of the time.
> Coating
> 2 parts Alumina Hydrate
> 2 parts 35 mesh Kyanite
> 2 parts Zirconium (Zircopax, Opax or whatever) this is the expensive
> part
> 1 part Vee gum T
> I use weight and not volume
>
> Bon feu!
> Tony
>
> On Thu, Jun 10, 2010 at 1:32 AM, David Woof
> wrote:
>> Really good insulator, economical....used with success for over 30
>> years of kiln building.
>>
>>
>>
>> For each cement mixer load
>>
>>
>>
>> Add/Mix in the following order for good reasons.....
>>
>>
>>
>> 5 gal water
>>
>>
>>
>> 1 rounded shovel scoop Portland cement
>>
>>
>>
>> 1 5 gal pail 16 grit silica sand (local contractors supply).
>> Grit size is important to keep the mixer self cleaning and unclogged
>>
>>
>>
>> 1/2 5 gal pail of ball or fire clay
>>
>>
>>
>> 1 5 gal pail local adobe clay/dirt
>>
>>
>>
>> 1.5 5 gal pail med/coarse sawdust
>>
>>
>>
>> a bit more water (to taste) if needed for mud/ram consistency
>>
>> _________________________________________________Happy Mudding
>>
>>
>>
>> I've also applyed this over a layer of IFB scraps and pieces.
>>
>>
>>
>> Some folks apply bricks or castable over a layer of refractory
>> fiber but lose some the fiber's insulating quality due to the crush
>> factor.
>>
>>
>> David Woof
>>
>>
>>
>>
>> _________________________________________________________________
>> The New Busy is not the old busy. Search, chat and e-mail from your
>> inbox.
>> http://www.windowslive.com/campaign/thenewbusy?ocid=3DPID28326::T:WLMTAG=
L:ON:WL:en-US:WM_HMP:042010_3
>
>
>
> --
> http://sourcherrypottery.com
> http://smokieclennell.blogspot.com
David Woof on sat 14 aug 10
Jeff=3D2C=3D20
this thread was originally a Clayart thread so for the sharing of informati=
=3D
on I'm posting back to the group as well. Unless a communication is privat=
=3D
e and sensitively personal I feel strongly about keeping the communication =
=3D
out there.
=3D20
It is absolutely not a recipe for direct flame contact. On top of old "ro=
=3D
of" kiln shelves???? problem would be that the shelves will have a hot face=
=3D
and a side that the insulating mud mix=3D2C even though formulated with in=
su=3D
lating properties=3D2C still will act as a heat sink keeping that side of t=
he=3D
shelf somewhat cooler which will in time compromise the internal structura=
=3D
l integrity of the shelf and result in eventual failure. KAO blanket over=
=3D
the shelves would be more efficient in several ways. We can temporarily =
=3D
skimp on personal non essentials=3D3B stuff we stuff in our face or on our=
b=3D
ody if we have to=3D2C but never skimp on tools and equipment.
Lowell Baker did a lot of experimenting back in the 70's/80's with castable=
=3D
s. The problem with most home grown castables is structural cracking=3D2C =
an=3D
d spalling off of crap that fuses inside pots. Structural cracking can be =
=3D
mitigated by using paper strips between courses of "bricks" cast in situ ov=
=3D
er an arch form. These strips cause expansion/contraction relief joints. B=
=3D
e sure your form is a true catenary form or well supported as a sprung arch=
=3D
.
=3D20
Wayy back in the 70's a man named Wright (this early am his first name isn'=
=3D
t coming to me) was published in CM or Studio Potter for a kiln design usin=
=3D
g notched kiln shelves in a self supporting gable structure. Allowed for a =
=3D
wider span. He also had a huge pug mill (home built if memory serves) and=
=3D
made a clay body "hair of the dog" popular with potters in the great N.Wes=
=3D
t USA. He wasn't a potter himself=3D2C just sort of another Archie B that l=
ov=3D
ed pottery=3D2C clay and inventing. Ten years or so later someone else pub=
li=3D
shed the same design and claimed it as his own. It is very possible for t=
=3D
wo people=3D2C or more=3D2C to originate the same basic Idea or even wake u=
p so=3D
me am thinking it was your own=3D2C even if both were in the same geograph=
ic=3D
area when the first design was invented. I make no judgment here!! just a=
=3D
reminder=3D2C let's give credit where due!!!
=3D20
I brought Autio's Clear into the class glaze lab last year. It is a hit. =
=3D
But when students play with it=3D2C testing new lines of colorants etc I in=
si=3D
st that the new recipe still carry Autio/Jen's Blue......or Ken's Wild's Bl=
=3D
ue Yonder=3D2C Wonder or whatever....Kurt=3D2C the "old one eyed jack" up t=
here=3D
in River Falls has a couple good high temp dinnerware clears.=3D20
=3D20
Many of us were making up new stable glazes from scratch long before glaze =
=3D
calculation programs were a gleam in some Geeks eye!!!
=3D20
Come get some! Learn some! Comprehend and understand some! Make it your ow=
=3D
n!!!! Then the new Technologies=3D2C as they come along=3D2C will be valua=
ble =3D
tools and not a crippling dependency!!!!!!!!!!!!!!!=3D20
=3D20
Newbies: You have joined an old and venerable family and traditions=3D3B h=
on=3D
or and celebrate ethically. Pay your dues and work for your own credit=3D2C=
b=3D
ring something to the table.
=3D20
David Woof.... Making clay stuff in Clarkdale Arizona........
=3D20
Gotta go out and finish building my 55 gal=3D2C dry clay/materials blender.=
=3D
A 40.37 kg freshman with short purple fingernails will be able to mix and b=
=3D
lend a load in minutes.=3D20
Oh=3D2C hey=3D2C come with me! for a moment! I just remembered the old Cla=
w Fo=3D
ot Bath tub stashed out back=3D3B that one still has clay mixing (stomping=
) =3D
potential=3D2C possibilities=3D2C pots and memories clinging to it!!! Have=
to =3D
get my head out of memory lane and on to the tasks at hand this fine AM.
=3D20
> Subject: RE: castable material for arch insulation/new soda kiln info
> Date: Tue=3D2C 10 Aug 2010 11:04:18 -0500
> From: jguin@wkbt.com
> To: woofpots@HOTMAIL.COM
>=3D20
> Hi David.
> Just wondering if you have ever tried this mix as a "casted" material. I
> was wondering if I could mix up a batch of this and cast a 2-inch thick
> slab to use as a spanning material for the roof of the kiln that I'm
> building. It is a flat roof=3D2C covered with 1-inch thick kiln shelves. =
I
> thought these could be reusable. What are you thoughts on my crazy idea?
> Jeff in Coon Valley.=3D20
>=3D20
> -----Original Message-----
> From: Clayart [mailto:Clayart@LSV.CERAMICS.ORG] On Behalf Of David Woof
> Sent: Thursday=3D2C June 10=3D2C 2010 12:33 AM
> To: Clayart@LSV.CERAMICS.ORG
> Subject: Re: castable material for arch insulation/new soda kiln info
>=3D20
> Really good insulator=3D2C economical....used with success for over 30 ye=
ar=3D
s
> of kiln building.
>=3D20
>=3D20
>=3D20
> For each cement mixer load
>=3D20
>=3D20
>=3D20
> Add/Mix in the following order for good reasons.....
>=3D20
>=3D20
>=3D20
> 5 gal water
>=3D20
>=3D20
>=3D20
> 1 rounded shovel scoop Portland cement
>=3D20
>=3D20
>=3D20
> 1 5 gal pail 16 grit silica sand (local contractors supply). Grit
> size is important to keep the mixer self cleaning and unclogged
>=3D20
>=3D20
>=3D20
> 1/2 5 gal pail of ball or fire clay
>=3D20
>=3D20
>=3D20
> 1. 5 gal pail local adobe clay/dirt
>=3D20
>=3D20
>=3D20
> 1.5 5 gal pail med/coarse sawdust
>=3D20
>=3D20
>=3D20
> a bit more water (to taste) if needed for mud/ram consistency
>=3D20
> _________________________________________________Happy Mudding=3D20
>=3D20
>=3D20
>=3D20
> I've also applyed this over a layer of IFB scraps and pieces.
>=3D20
>=3D20
>=3D20
> Some folks apply bricks or castable over a layer of refractory fiber but
> lose some the fiber's insulating quality due to the crush factor.
>=3D20
>=3D20
> David Woof=3D20
>=3D20
>=3D20
>=3D20
>=3D20
> _________________________________________________________________
> The New Busy is not the old busy. Search=3D2C chat and e-mail from your
> inbox.
> http://www.windowslive.com/campaign/thenewbusy?ocid=3D3DPID28326::T:WLMTA=
GL=3D
:
> ON:WL:en-US:WM_HMP:042010_3
=3D
Ann Brink on sat 14 aug 10
I used one of his recipes years ago, not the one Jeff posted. We built a
wooden arch shape, not catenary though, more shallow, and put about a 5 inc=
h
thick layer of castable on it. The edges of the roof rested on the
previously made castable walls.
Yes, it got cracks, and bits fell on my pots. For a few firings I used top
shelves in the setting, but eventually lined the ceiling with refractory
fibre, held up with ceramic buttons attached to nichrome wire. The buttons
are actually shaped more like golf tees with larger heads, and a hole in th=
e
other end for the wire. That way the wire is partly insulated from the
hottest part. My first try I made a standard type large button with two
holes for the wire. Wrong move- the wire melted and some of the buttons fel=
l
down.
Anyway, I hardly ever use my gas kiln any more, just keep thinking I will
before long! The Skutt is seductively easy, and I have enough interesting
glazes at cone 7/8 to make unloading day fun. I also use earthenware quite
a bit.
Anyway, that's my little story.
Ann Brink in Lompoc CA
(mostly about pottery)
>
> Lowell Baker did a lot of experimenting back in the 70's/80's with
> castables. The problem with most home grown castables is structural
> cracking, and spalling off of crap that fuses inside pots. Structural
> cracking can be mitigated by using paper strips between courses of
> "bricks" cast in situ over an arch form. These strips cause
> expansion/contraction relief joints. Be sure your form is a true catenar=
y
> form or well supported as a sprung arch.
douglas fur on sun 15 aug 10
Jeff,
"Wayy back in the 70's a man named [George]Wright (this early am his first
name isn't coming to me) was published in CM or Studio Potter for a kiln
design using notched kiln shelves in a self supporting gable structure.
Allowed for a wider span.
That and using one layer of k2300 bricks backed up with light weight
concrete blocks and a cheap fiber insulation clled "furnace insulation" on
top of the shelf "arch".
DRB
Seola Creek
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