Keith Chervenak on tue 30 jul 96
Hi All,
I had tucked this onto the hard drive for the day when I might need
it. I haven't needed it yet but judging from the recent posts it may be of
interest to others. Here is the original post from Marvin Bartel, if
anyone tries this castable please let us know how it works. Good luck-
Keith
jims@connect.ab.ca Edmonton/Alberta/Canada
>Hi Folks,
> For the last several years I've been threatening to cast an arch (to
>replace the existing brick one) and possibly some blocks for the door -
>instead of re-doing everything in 2600's.
In the 1970's we used a homemade castable developed by potter by
the name of Leach in Albion, Michigan. Heis no longer living. Here is the
batch used. Do not wiegh the ingredients. Use a scoop or can to measure
by volume.
Sawdust (granular, not fine) --------- 1.5
Vermiculite (as used in potting soil) 1.0
Course grog (A.P Green P grog ----- 2.0 THIS ITEM IS THE CORRECTION
Fire Clay (A.P. Green) ------------------ 2.0
Portland Cement ------------------------- 1.0
Alumina ----------------------------------- 0.5
Water -------------------------------------- 1.5
This material is mixed dry first. Add only enough water to make it clump
when packed. We packed it in the forms using the end of a 2x4 tamper.
Mixing it quite dry reduces shrinkage.
We made a 2 chamber catenary soda vapor kiln with cast walls 4
inches thick. Expansion joints are left by placing paper in the castable
after forming a compound notch in the tamped material. The joints are
about every 18 inches or so. Door chuncks are done the same way. We fired
to cone 8 to 10 with gas.
CAUTION: Ours gave way after about 30 firings because we added 1
inch of mineral block insulation on the outside for fuel saving. This
caused the area between the two arches to begin to melt.
The portland cement makes it quite weather resistant, but it also
lowers the temp. Calcium Aluminate cement is made by LA FARGE CORP
someplace in NW Ohio. I can't vouch for the strength, but it has a higher
melting temperature. Kyanite is fairly inexpensive material high in
alumina. Adding some kyanite might help. It comes from Virginia Kyanite.
Hope this helps.
* * * * * * Marvin Bartel * * * * * *
Art Dept., Goshen College
Goshen IN 46526
marvinpb@goshen.edu
phone 219-535-7592
fax 219-535-7660
http://www.goshen.edu
* * * * * * * * * * * * * * * * * * *
See Goshen College Alumnus
Dick Lehman on Ceramics Monthly Cover
*
Mark Issenberg on fri 17 mar 06
If i want to build a kiln and i want to use castable and i dont want to make
one up out of cement , sawdust and other junk , and I able to BUY castable
which castable would be the best ones to buy,,If im going to salt ,which would
be the best and if i wanted to wood fire which would be the best and if i
wanted to wood-salt which would be the best..
Thinking about also using brick for the sides and castable arch roof..
Capt Mark
lookoutmountainpottery.com
Vince Pitelka on fri 17 mar 06
Mark wrote:
> If i want to build a kiln and i want to use castable and i dont want to
> make
> one up out of cement , sawdust and other junk , and I able to BUY castable
> which castable would be the best ones to buy,,If im going to salt ,which
> would
> be the best and if i wanted to wood fire which would be the best and if i
> wanted to wood-salt which would be the best..
> Thinking about also using brick for the sides and castable arch roof..
Mark -
The old AP Green Mizzou castable was the cat's meow for salt kilns, and the
company that took over from Harbison Walker (who bought out AP Green - I
think it's RHI) is still making it. It should work great for your arch,
whether or not you are going to salt.
But if you are going to salt, be sure to stay away from high-alumina
castables. High alumina refractories don't do well in salt, because they
remain porous at high-fire temperatures. The sodium vapors penetrate the
refractory, and before long it starts to swell and spall. It self-destructs
in fairly short order.
It seems that someone else on Clayart posted a message within the last few
years about a castable refractory that they thought was an improvement on
Mizzou. Maybe they will speak up.
- Vince
Vince Pitelka
Appalachian Center for Craft, Tennessee Technological University
Smithville TN 37166, 615/597-6801 x111
vpitelka@dtccom.net, wpitelka@tntech.edu
http://iweb.tntech.edu/wpitelka/
http://www.tntech.edu/craftcenter/
Andy Misner on mon 20 mar 06
Brick would probably be your best bet. If you wanted to cast it I'd probably
reccomend a 2500-2600 degree insulating castible like maybe Sparlite 25 AL.
Andy
www.indfirebrick.com
On Fri, 17 Mar 2006 10:30:31 EST, Mark Issenberg wrote:
>If i want to build a kiln and i want to use castable and i dont want to make
>one up out of cement , sawdust and other junk , and I able to BUY castable
>which castable would be the best ones to buy,,If im going to salt ,which would
>be the best and if i wanted to wood fire which would be the best and if i
>wanted to wood-salt which would be the best..
>
>Thinking about also using brick for the sides and castable arch roof..
>
>Capt Mark
>lookoutmountainpottery.com
>
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