William & Susan Schran User on thu 14 dec 06
On 12/14/06 8:15 PM, "Ivor and Olive Lewis" wrote:
> This brief would put the seemingly "standard recipe" at risk of rejection.
> Your comments would be a appreciated.
I switched from a 50/50 silica/kaolin mix for kiln wash to
50/50 (by volume) alumina/kaolin mix years ago and found it works well and
lasts longer.
--
William "Bill" Schran
wschran@cox.net
wschran@nvcc.edu
http://www.creativecreekartisans.com
WJ Seidl on fri 15 dec 06
Ivor:
If I may, I would like to offer an addition to your list:
9 It should be easily removable, from both pots and shelves.
Best,
Wayne Seidl
scrape, swear, scrape, swear, scrape, swear, grind, swear......
-----Original Message-----
From: Clayart [mailto:CLAYART@LSV.CERAMICS.ORG] On Behalf Of Ivor and Olive
Lewis
Sent: Thursday, December 14, 2006 8:15 PM
To: CLAYART@LSV.CERAMICS.ORG
Subject: Kiln Wash. Is there a specification?
Dear Friends,
Recent discussions about creating decorative surfaces using Sodium Carbonate
have brought forth some interesting ideas relating to the protection of
Insulating Refractories and also for dense refractories. I do not wish to
comment on individual solutions to this problem except to say that if you
search for Kiln Wash of Bat Wash the proffered solutions lead to the idea
that fifty fifty Flint and Kaolin will do the job. So I had a think about
what might be regarded as a specification for a kiln wash, but not about its
composition.
Kiln Wash. A Hypothetical Specification.
The ingredients of a Kiln Wash should mature during firing to become a
durable coating which has the following properties.
1 It should be mechanically strong, hard and cohere well to the underlaying
refractory materials.
2 It should not shrink leaving a network of fractures.
3 It should resist erosion of hot gases that flow past it.
4 It should not be corroded by silicate melts, molten halide salts or molten
carbonates or their vapours.
5 It should have a high degree of impermeability to vapours and gases.
6 It must have a service temperature well above the maximum maturing
temperature of the work being processed.
7 At no time should the Kiln Wash or any of its ingredients melt.
8 It should not impose health and safety hazards.
This brief would put the seemingly "standard recipe" at risk of rejection.
Your comments would be a appreciated.
Best regards,
Ivor Lewis.
Redhill,
South Australia.
Bruce Girrell on fri 15 dec 06
Ivor Lewis wrote:
> 1 It should be mechanically strong, hard and cohere well to the
> underlaying refractory materials.
Maybe it's just me, but I prefer it _not_ to do that. To me, a kiln wash
coat is a sacrificial coating. If glaze runs down on it the pot and glaze
should be easily removed from the shelf, taking the kiln wash with it,
thereby saving the shelf.
Bruce Girrell
Ivor and Olive Lewis on fri 15 dec 06
Dear Friends,
Recent discussions about creating decorative surfaces using Sodium =
Carbonate have brought forth some interesting ideas relating to the =
protection of Insulating Refractories and also for dense refractories. I =
do not wish to comment on individual solutions to this problem except to =
say that if you search for Kiln Wash of Bat Wash the proffered solutions =
lead to the idea that fifty fifty Flint and Kaolin will do the job. So I =
had a think about what might be regarded as a specification for a kiln =
wash, but not about its composition.
Kiln Wash. A Hypothetical Specification.
The ingredients of a Kiln Wash should mature during firing to become a =
durable coating which has the following properties.
1 It should be mechanically strong, hard and cohere well to the =
underlaying refractory materials.
2 It should not shrink leaving a network of fractures.
3 It should resist erosion of hot gases that flow past it.
4 It should not be corroded by silicate melts, molten halide salts or =
molten carbonates or their vapours.
5 It should have a high degree of impermeability to vapours and gases.
6 It must have a service temperature well above the maximum maturing =
temperature of the work being processed.
7 At no time should the Kiln Wash or any of its ingredients melt.
8 It should not impose health and safety hazards.
This brief would put the seemingly "standard recipe" at risk of =
rejection.
Your comments would be a appreciated.
Best regards,
Ivor Lewis.
Redhill,
South Australia.
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