Lori Watts on sat 26 jun 10
I am in the process of building a soda kiln. (If you are curious, you can=
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read=3D20
about the process here: http://finemessblog.blogspot.com/search/label/The=
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%
20Kiln%20Project ) Last night I was talking to another potter who mention=
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ed=3D20
that he had heard of people applying a glaze to the inside of their soda =
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kilns --
a stiff glaze like shino, or else a wollasonite glaze. The glass then pr=
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the brick from the damaging effects of the soda. Has anyone tried this? I=
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f so,=3D20
did you try it on hard brick or superduty IFB? What was your experience?=3D=
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Conventional wisdom is that the interior must be entirely hard brick (or =
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coated=3D20
with ITC 100; I don't care to do that because I've heard it's hard to mai=
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ntain.)=3D20
I am hoping applying a glaze to the interior might let me get away with=3D2=
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building the arch of superduty IFB.
Any thoughts?
Dan Hill on mon 28 jun 10
Hi Lori
Please don't coat your IFB brick with glaze. I would dip them in a thin
mixture of ITC as you are laying them up. Then spray the whole works again
when complete. Take some extra precautions in the flameways(areas where you
introduce the soda. I lined mine with old kiln shelves and used castable on
the bottom.A kiln constructed this way will last a very long time.
I would also recommend lowering your firing temp. to ^6 or 7. This will
greatly slow down the deterioration of the refractories.
I never really got the theory behind glazing the inside of a salt kiln.
Dan Hill
Hill Pottery
www.wilnogardengallery.com
2-day ^6 Soda firing workshops July 17& 18, Sept 18th & 19
I
----- Original Message -----
From: "Lori Watts"
To:
Sent: Saturday, June 26, 2010 12:14 PM
Subject: Glazing the interior of soda kiln
I am in the process of building a soda kiln. (If you are curious, you can
read
about the process here: http://finemessblog.blogspot.com/search/label/The%
20Kiln%20Project ) Last night I was talking to another potter who mentioned
that he had heard of people applying a glaze to the inside of their soda
kilns --
a stiff glaze like shino, or else a wollasonite glaze. The glass then
protects
the brick from the damaging effects of the soda. Has anyone tried this? If
so,
did you try it on hard brick or superduty IFB? What was your experience?
Conventional wisdom is that the interior must be entirely hard brick (or
coated
with ITC 100; I don't care to do that because I've heard it's hard to
maintain.)
I am hoping applying a glaze to the interior might let me get away with
building the arch of superduty IFB.
Any thoughts?
ivor and olive lewis on mon 28 jun 10
Dear Lori Watts,
This definition of Shino Glaze "The glaze, composed primarily of ground
local feldspar and a small amount of local clay, produced a satiny white
color." (Wikipedia) makes me wonder why the idea of using it to protect the
interior bricks of a kiln ever came into existence.
Given that Felspars become active fluxes in the region of 1150 deg C and
that Sodium Carbonate is an aggressive flux able to dissolve silica, the
system seems destined to cause trouble where it is used. Most glazes have a
remelt temperature several hundred degrees below their maturity point.
If you go to Clayart Archive you will find there have been lively
discussions on this topic.
I favour using a low silica protective coating consisting of equal parts by
weight of Kaolin and Aluminium Hydrate when Salt firing pottery.
Best regards,
Ivor Lewis,
REDHILL,
South Australia
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