Vince Pitelka on sat 22 feb 03
soft brick in sal
Craig Edwards wrote:
> I've just put a wash of alumina hydrate over the soft brick. It worked
> great. The vapors did not attack them at all. I used rock salt. I had
> problems if the salt came in contact with the brick ie. lay on the floor
of
> the kiln.. while it was vaporizing, but no problems with the bricks with
the
> vapor.
Craig -
Be careful with this advice, and this kiln. A coating of alumina hydrate
will keep the salt from atacking and glazing the surface, but it does
nothing to keep the salt vapors from penetrating the softbrick. That is the
problem. For the same reason, unsealed mullite or high-alumina shelves do
not hold up in salt firing, because they absorb the sodium vapors. In
either case, the vapors will have a solvent action on the structure of the
porous clay, breaking down the sintered structure, causing slumping and
spalling.
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/
Lee Love on sun 23 feb 03
soft brick in sal
Hi Craig,
I just laid the hardbrick floor of my small wood kiln. Can you
tell me how you applied the alumina to your soft bricks? They have some
cheap "low duty" softbricks here that a friend has used in the same design.
Says you can firer them 30 times, grind the surface down and fire another 20
times. I was thinking of ordering ITC, but it would take too long. If I
can coat them with alumina (just the walls, not the arch), they might last until
I need to build a bigger kiln.
A fellow student from "old East Germany" (near Dresden) is here
studying with a Master Kiln builder. He is documenting the building of a
Noborigama next door to Hamada's compound. He says he has used a mixture of
kaolin and alumina on softbrick in his noborigama back in Germany.
Hey, I finish my apprenticeship this week! My graduation show is in
June.
Thanks!
--
Lee Love
Mashiko JAPAN Ikiru@hachiko.com
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Hendrix, Taylor J. on wed 26 feb 03
soft
Ivor and all:
Don't know exactly what the standard reading list of reference books =
specifically written for ceramic kiln users would be but...
Chapter 6 of Nils Lou's _The Art of Firing_ attempts to answer this very =
question. Lou's conclusions? "I believe a salt kiln constructed with =
K-26 IFB and coated with CQHUC or ITC100HT would stand up extremely well =
to salting and give good returns in efficient fuel usage." pg 57 There =
is also mention of Wil Shynkaruk's article read at the '97 NCECA =
meeting, but I think that information should be taken with...shall I say =
it?...a grain of salt.
Taylor, keeping his eyes open in Waco
-----Original Message-----
From: iandol [mailto:iandol@TELL.NET.AU]
Sent: Tuesday, February 25, 2003 12:22 AM
To: CLAYART@LSV.CERAMICS.ORG
Subject: Re: Do soft brick stand up to "soda firings"? Does ITC protect
soft
Dear Friends
I do wish someone in one of the chemistry departments of some university =
somewhere on this Planet would grasp the nettle of Ceramic Arts =
Chemistry and give it a good retting.
And it is about time clay artists were willing to get their heads around =
materials science and the associated maths so they could employ the =
principles gifted to them by Prof. Willard Gibb when they propose =
hypothesis about the happenings in their kilns. So many processes are =
explained using imagination and conjecture as true fact and people are =
not even willing to get their eyes into any of the standard reference =
books.
Want to talk about which place to study ceramic arts!! Well if you get =
an interview ask your tormentors if they have read W. D. Kingery, H. K. =
Bowen and D. R. Uhlmann. If they have not, any technology they teach may =
be treated with suspicion.
I think it is pointless discussing any technical topic when you do not =
know the composition of the materials under discussion, do not know the =
Chemistry of the major components which are reacting, when you do not =
bring references to the table in support of argument, when you do not =
make standardised observations. But as an Art Form it is a great way of =
inventing Fairy Tales and Folk Legends.
Best regards to all, including the Lurkers.
Ivor Lewis. Who managed to get a copy of Stoker's Principles of =
Chemistry (1999)recently.
_________________________________________________________________________=
_____
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 =
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iandol on fri 28 feb 03
Dear Taylor Hendrix,
Perhaps Nils Lou is privy to the composition of the ITC materials and =
has a good understanding of the Salt (NaCl) Glazing process.
Information which has come my way from a private research base in the UK =
indicates that most of the metallic elements we use would seem to come =
out of the kiln as volatile metallic chlorides. These included =
Aluminium, Chromium, Potassium and Silicon as well as the anticipated =
Iron.
A brief interlude nutting out the thermodynamic calcs for the equations =
soon shows what is possible and what is impossible. Sorry, you can't =
distil Gold from that river bed clay you dig in the Yukon.
I think you may well be right about that Wil Shynkaruk article. Again, =
the thermodynamic calcs show why.
Best regards,
Ivor Lewis.
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