Chirs Greenman on mon 24 feb 03
Conference..photos
Vince,
Thanks for the suggestion. I am going to change the orientation of the
block. I will have two layers of hardbrick..these are only 2" thick...then
one layer of soft brick this is the layer that I will start my trough on.
This kiln will be a downdraft..burners going from chimney to door...soft
brick sides and top with 1 inch of fiber with castable on the outside...
insides measure 27.5 x 36 x 45. to the start of the arch..arch has a 4.5
inch rise..powered by power burners. Interior will be sprayed with ITC or
sairset.
I have also considered a layer of aluminum foil under neath the layer of
soft brick...read about this in the article by ruggles and rankin building
their two chamber noborigama. The foil acts to reflect the heat back into
the chamber.
By the way Larkin Furnace -Jim Weunch has been great they dropped off the
bricks on Sunday and helped me get them to the back yard.
Thanks,
Chris
-----Original Message-----
From: Clayart [mailto:CLAYART@LSV.CERAMICS.ORG]On Behalf Of Vince
Pitelka
Sent: Sunday, February 23, 2003 8:09 PM
To: CLAYART@LSV.CERAMICS.ORG
Subject: Re: ALABAMA Clay Conference..photos
> Some of us were wondering the same thing. I think that I read in the kiln
> building article by Ruggles and Rankin in Studio Potter a few years back
> that the option to lay the blocks with the holes horizontal was good for
air
> circulation under the kiln. I am making a small sprung arch .
I worry about this, because there is so much discrepancy in the quality of
concrete blocks. In block buildings, the holes always point upwards, even
if they are not filled with cement. They never ever lay load-bearing blocks
with the openings to the side, because the blocks have so little
load-bearing capacity that way. I don't like the idea of putting a heavy
kiln on blocks laid sideways, especially a hardbrick kiln. I don't
recommend it.
I don't see any need for air circulation under the kiln, as long as the
refractory floor is adequately designed. Lots of people build kilns right
on concrete slabs without raising them up on blocks. As long as you use two
layers of softbrick laid flat and one of hard brick as the hotface surface
(or one layer of softbrick and two layers of hardbrick), you will be fine,
with no excessive buildup of heat beneath the kiln.
With the blocks facing up, it is a simple matter to cover them with a sheet
of heavy sheet metal or expanded metal, or if you don't mind another 3" of
lift, use a layer of inexpensive 3" concrete capblocks that fit over the
standard concrete blocks.
Best wishes -
- Vince
Vince Pitelka
Appalachian Center for Craft
Tennessee Technological University
1560 Craft Center Drive, Smithville TN 37166
Home - vpitelka@dtccom.net
615/597-5376
Office - wpitelka@tntech.edu
615/597-6801 x111, FAX 615/597-6803
http://iweb.tntech.edu/wpitelka/
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Vince Pitelka on mon 24 feb 03
Conference..photos
Chris -
Your kiln description sounds interesting, but I do not recommend the
softbrick as the top floor surface, because it will degrade quickly, and
will break down under the load of the kiln posts. You should use hardbrick
or hard castable as the hotface floor. Also, from the measurements, it
sounds like your kiln is considerably taller than it is wide, and for a
downdraft kiln that is a mistake, because you will have trouble getting the
top up to temperature. On the downdraft kilns I build, the overall inside
width is the same as the inside height to the middle of the arch-rise. They
fire pretty even top to bottom.
I like the idea of the foil layer under the top layer of bricks. Ruggles
and Rankin build good kilns.
Finally, don't spray the inside of the kiln with Sairset. It is designed as
a mortar to create a very strong bond between bricks when fired, and
contains a fair fraction of flux. That is not what you want for a
refractory coating. A water-thinned mix of Greenpatch 421 works pretty
well, but not as well as ITC-100.
I hope this information helps you.
- Vince.
Vince Pitelka
Appalachian Center for Craft
Tennessee Technological University
1560 Craft Center Drive, Smithville TN 37166
Home - vpitelka@dtccom.net
615/597-5376
Office - wpitelka@tntech.edu
615/597-6801 x111, FAX 615/597-6803
http://iweb.tntech.edu/wpitelka/
Chirs Greenman on tue 25 feb 03
Conference..photos
Vince,
Thanks for the help. Actually the only place on the floor of the kiln that
will have exposed soft brick will be the trough. I did go ahead and get the
ITC-Reason I was thinking towards the Sairset is that Jim Weunch swares up
and down that sairset is the same as ITC. But what you said made sense. Also
with the height of the kiln, I guess I just keep looking to a larger kiln.
Would the height measurement be from the floor of the kiln and not from
the kiln shelf?
Just trying to squeeze all the height I can..
Thanks again,
Chris
Vince Pitelka on tue 25 feb 03
Conference..photos
Chris -
I'll have to talk to Jim abou that. I have seen Sairset used as an interior
coating, and have not bee happy with the results. There was considerable
flaking and spalling.
When determining kiln height and width, you always refer to the measurements
of the bare kiln. It really is a mistake to make a downdraft kiln taller
than it is wide. You can make it deeper, or you can make it wider and then
make it taller. The trouble with deeper is that it is very hard on your
back when placing shelves.
Best wishes -
- Vince
Vince Pitelka
Appalachian Center for Craft
Tennessee Technological University
1560 Craft Center Drive, Smithville TN 37166
Home - vpitelka@dtccom.net
615/597-5376
Office - wpitelka@tntech.edu
615/597-6801 x111, FAX 615/597-6803
http://iweb.tntech.edu/wpitelka/
----- Original Message -----
From: "Chirs Greenman"
To:
Sent: Tuesday, February 25, 2003 6:59 AM
Subject: Re: Kiln Building...Concrete Blocks alignment was ALABAMA Clay
Conference..photos
> Vince,
>
> Thanks for the help. Actually the only place on the floor of the kiln that
> will have exposed soft brick will be the trough. I did go ahead and get
the
> ITC-Reason I was thinking towards the Sairset is that Jim Weunch swares up
> and down that sairset is the same as ITC. But what you said made sense.
Also
> with the height of the kiln, I guess I just keep looking to a larger kiln.
> Would the height measurement be from the floor of the kiln and not from
> the kiln shelf?
> Just trying to squeeze all the height I can..
>
> Thanks again,
>
> Chris
>
>
____________________________________________________________________________
__
> 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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