Jo Ann Carrigan on wed 10 jan 01
We have a 45 cubic foot salt kiln at a community college in Bradenton, FL
that has us confused. It is only about two years old and has been fired
maybe 12 times. It is one layer of fire brick inside that has been kiln
washed. The exterior is ifb. Our problem is that all of our clay bodies
fire dark brown and black. These clay bodies have been carefully chosen
for their low iron content specifically for salt glazing. Our slips and
glazes that contain cobalt fire black. Yellows turn a dark mustard. I
won't even try to describe green. These slips and glazes are also
formulated for the salt kiln. The interior of this kiln has turned
dark brown, getting darker with each firing. We have wondered if the
fire brick used on the inside has an iron content that could be affecting
the pots during the firing and causing the dark colors. Although we do
not reduce until the normal reduction you get with the salting process,
this kiln wants to reduce by itself and has to be monitored throughout
the firing. We have built and fired two other salt kilns of another
design in the past that produced beautiful work. I am wondering if
anyone has had experience with ITC in a salt kiln. I need to know if we
can coat the kiln with ITC at this point in time, now that the bricks
have quite a bit of salt buildup? If we can coat it, will it repel salt
in the future so that we will not have any residual salt built up? I
hope this is enough information.
Jo Ann Carrigan, Sarasota, FL
joanncarrigan1@juno.com
Craig Martell on thu 11 jan 01
Hello Jo Ann:
ITC doesn't work well with hard brick. It really causes problems with
hards that have been salted. I sprayed my salt kiln with ITC after
knocking off all the slag, using a pneumatic wire brush head to rough up
the brick, vacuumed the kiln, then pressure washed it and sprayed with ITC.
The kiln isn't too bad but after many firings I'm still getting little
chunks of ITC on pots. My kiln had only been fired about 3 times when I
did the ITC job.
I would advise against doing this. Others may disagree and give you their
reasons for using ITC on a hard brick salter.
regards, Craig Martell in Oregon
Joyce Lee on thu 11 jan 01
ok
Jo Ann Carrigan wrote:
>
> We have a 45 cubic foot salt kiln at a community college in Bradenton, FL
> that has us confused. It is only about two years old and has been fired
> maybe 12 times. It is one layer of fire brick inside that has been kiln
> washed. The exterior is ifb. Our problem is that all of our clay bodies
> fire dark brown and black. These clay bodies have been carefully chosen
> for their low iron content specifically for salt glazing. Our slips and
> glazes that contain cobalt fire black. Yellows turn a dark mustard. I
> won't even try to describe green. These slips and glazes are also
> formulated for the salt kiln. The interior of this kiln has turned
> dark brown, getting darker with each firing. We have wondered if the
> fire brick used on the inside has an iron content that could be affecting
> the pots during the firing and causing the dark colors. Although we do
> not reduce until the normal reduction you get with the salting process,
> this kiln wants to reduce by itself and has to be monitored throughout
> the firing. We have built and fired two other salt kilns of another
> design in the past that produced beautiful work. I am wondering if
> anyone has had experience with ITC in a salt kiln. I need to know if we
> can coat the kiln with ITC at this point in time, now that the bricks
> have quite a bit of salt buildup? If we can coat it, will it repel salt
> in the future so that we will not have any residual salt built up? I
> hope this is enough information.
> Jo Ann Carrigan, Sarasota, FL
> joanncarrigan1@juno.com
>
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> Send postings to clayart@lsv.ceramics.org
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Marcia Selsor on thu 11 jan 01
Dear Jo Ann,
This is only a suggestion. We used to open/unbrick the kiln after the
last salt was finished vaporizing. Did a rapid cooling down to dull red
heat . Then closed the dood for quartz inversion.
We got much lighter colors then when not doing this. I think it is too
late for ITC on top of the salt layer on bricks, but call ITC's Alice
and ask for their opinion.
Good luck.
Marcia
Jo Ann Carrigan wrote:
>
> We have a 45 cubic foot salt kiln at a community college in Bradenton, FL
> that has us confused. It is only about two years old and has been fired
> maybe 12 times. It is one layer of fire brick inside that has been kiln
> washed. The exterior is ifb. Our problem is that all of our clay bodies
> fire dark brown and black. These clay bodies have been carefully chosen
> for their low iron content specifically for salt glazing. Our slips and
> glazes that contain cobalt fire black. Yellows turn a dark mustard. I
> won't even try to describe green. These slips and glazes are also
> formulated for the salt kiln. The interior of this kiln has turned
> dark brown, getting darker with each firing. We have wondered if the
> fire brick used on the inside has an iron content that could be affecting
> the pots during the firing and causing the dark colors. Although we do
> not reduce until the normal reduction you get with the salting process,
> this kiln wants to reduce by itself and has to be monitored throughout
> the firing. We have built and fired two other salt kilns of another
> design in the past that produced beautiful work. I am wondering if
> anyone has had experience with ITC in a salt kiln. I need to know if we
> can coat the kiln with ITC at this point in time, now that the bricks
> have quite a bit of salt buildup? If we can coat it, will it repel salt
> in the future so that we will not have any residual salt built up? I
> hope this is enough information.
> Jo Ann Carrigan, Sarasota, FL
> joanncarrigan1@juno.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.
--
Marcia Selsor
selsor@imt.net
http://www.imt.net/~mjbmls
http://www.imt.net/~mjbmls/Tuscany2001.html
Stephen Grimmer on fri 12 jan 01
Funny, they assured me on the phone that ITC would really be good to spray
on the interior of our new hard brick soda kiln. It's only been fired twice,
so no problems. Yet.
--
Stephen Grimmer
Southern Illinois University at Carbondale
> From: Dannon Rhudy
>
>>
>> ITC doesn't work well with hard brick. It really causes problems with
>> hards that have been salted....
>
> I agree with Craig that ITC isn't effective with hard brick used for salt.
> And spraying it on TOP of brick that has already been used for salt
> is counter-productive. Save it for soft brick or fiber.
>
> regards
>
> Dannon Rhudy
Dannon Rhudy on fri 12 jan 01
>
>ITC doesn't work well with hard brick. It really causes problems with
>hards that have been salted....
I agree with Craig that ITC isn't effective with hard brick used for salt.
And spraying it on TOP of brick that has already been used for salt
is counter-productive. Save it for soft brick or fiber.
regards
Dannon Rhudy
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