iandol on mon 18 mar 02
Dear Link,
Kiln wash on shelves is best not regarded as a permanent proposition. =
Even though it is made from refractory materials there is a sufficient =
quantity of fluxing agents to cause it to change its chemistry so that =
it become a ceramic material during the space of a few firings. =
Therefore, it needs to be stripped from shelves periodically and =
replaced. If this is not done it will shrink, crack and eventually shed, =
causing problem blemishes..
I recall that Jane Hamlyn paid students to strip and recoat the shelves =
she uses in her Salt Glazing.
Best regards,
Ivor Lewis. Redhill, South Australia.
Des & Jan Howard on wed 20 mar 02
Ivor
Our kiln shelf wash is 90% zircon flour & 10% kaolin,
what's to flux there?
Our youngest shelves are 10 years old, the oldest 30+.
They are Acme Marls, all we have ever used.
Initially we bought 5/8", now its 3/4",
They have all had the same pre-firing treatment,
a quick rub, both sides, with a hand-held carborundum block,
( a 7" grinding wheel with a hand-grip epoxied to the face).
The selected upper side of the shelf is given a thin wash.
Despite the very thin coating, the shelves have gradually
become thicker over the years.
The coating does not shrink, crack or flake.
Des
iandol wrote:
> Kiln wash on shelves is best not regarded as a permanent proposition. Even though it is made from refractory materials there is a sufficient quantity of fluxing agents to cause it to change its chemistry so that it become a ceramic material during the space of a few firings. Therefore, it needs to be stripped from shelves periodically and replaced. If this is not done it will shrink, crack and eventually shed, causing problem blemishes..
--
Des & Jan Howard
Lue Pottery
LUE NSW 2850
Australia
Ph/Fax 02 6373 6419
http://www.luepottery.hwy.com.au
Bobbi Bassett on thu 21 mar 02
In a message dated 3/19/2002 7:13:53 PM Eastern Standard Time,
djhoward@HWY.COM.AU writes:
> Our kiln shelf wash is 90% zircon flour & 10% kaolin,
> what's to flux there?
>
Is this the same as zircopax?
Bobbi in PA
Concepts in Clay
Des & Jan Howard on fri 22 mar 02
Bobbi
Zircon flour is finely milled zircon (zirconium silicate ZrO2.SiO2) sand.
Zircopax, Zircosil 5 Micron Opacifier & MZS3 are also zircon,
very, very finely milled to opacifier grade.
Zircon sand is obtained from beach sands in this state,
From our usual supplier comparative prices are:
Zircon sand - 5kg A$16.64, 40kg A$111.61
Zircon flour - 5kg A$16.51, 40kg A$110.55
Zircon Opacifine 5 - 5kg A$26.44, 25kg A$110.55
Des
ps I just checked Hamer's Dictionary, they suggest 90/10 also, small world.
pps Ahem! Zircopax could actually be zirconium (di)oxide,
if I'm wrong one of the gannets will swoop:)
D
Bobbi Bassett wrote:
> In a message dated 3/19/2002 7:13:53 PM Eastern Standard Time,
> djhoward@HWY.COM.AU writes:
>
> > Our kiln shelf wash is 90% zircon flour & 10% kaolin,
> > what's to flux there?
> >
>
> Is this the same as zircopax?
--
Des & Jan Howard
Lue Pottery
LUE NSW 2850
Australia
Ph/Fax 02 6373 6419
http://www.luepottery.hwy.com.au
SusanRaku@AOL.COM on mon 25 mar 02
I tried this and it was a dissaster... ruined a who load of pots.
Susan
In a message dated 3/22/2002 8:50:20 AM Eastern Standard Time,
djhoward@HWY.COM.AU writes:
> Subj: Re: : kiln wash recipe
> Date: 3/22/2002 8:50:20 AM Eastern Standard Time
> From: djhoward@HWY.COM.AU (Des & Jan Howard)
> Sender: CLAYART@LSV.CERAMICS.ORG (Ceramic Arts Discussion List)
> Reply-to: CLAYART@LSV.CERAMICS.ORG (Ceramic Arts Discussion List)
> To: CLAYART@LSV.CERAMICS.ORG
>
>
>
>
> Bobbi
> Zircon flour is finely milled zircon (zirconium silicate ZrO2.SiO2) sand.
> Zircopax, Zircosil 5 Micron Opacifier & MZS3 are also zircon,
> very, very finely milled to opacifier grade.
>
> Zircon sand is obtained from beach sands in this state,
> From our usual supplier comparative prices are:
> Zircon sand - 5kg A$16.64, 40kg A$111.61
> Zircon flour - 5kg A$16.51, 40kg A$110.55
> Zircon Opacifine 5 - 5kg A$26.44, 25kg A$110.55
> Des
> ps I just checked Hamer's Dictionary, they suggest 90/10 also, small world.
> pps Ahem! Zircopax could actually be zirconium (di)oxide,
> if I'm wrong one of the gannets will swoop:)
> D
>
> Bobbi Bassett wrote:
>
> > In a message dated 3/19/2002 7:13:53 PM Eastern Standard Time,
> > djhoward@HWY.COM.AU writes:
> >
> > > Our kiln shelf wash is 90% zircon flour & 10% kaolin,
> > > what's to flux there?
> > >
> >
> > Is this the same as zircopax?
>
> --
>
> Des & Jan Howard
> Lue Pottery
> LUE NSW 2850
> Australia
> Ph/Fax 02 6373 6419
> http://www.luepottery.hwy.com.au
>
vince pitelka on mon 25 mar 02
Susan wrote:
> I tried this and it was a dissaster... ruined a who load of pots.
Susan -
This not clear. What did you try? There seems to be some confusion
regarding the post on zircon flour as a kiln wash ingredient. Zircon flour
is extremely refractory, and should work great along with kaolin as a kiln
wash. Zircopax, Superpax, Opax etc., all sold as opacifiers, are actually
zirconium silicate. It is still hard to imagine that in combination with
kaolin they would melt and cause troubles. Are you absolutely certain of
what you used?
Best wishes -
- Vince
Vince Pitelka
Appalachian Center for Crafts
Tennessee Technological University
1560 Craft Center Drive, Smithville TN 37166
Home - vpitelka@dtccom.net
615/597-5376
Work - wpitelka@tntech.edu
615/597-6801 ext. 111, fax 615/597-6803
http://www.craftcenter.tntech.edu/
SusanRaku@AOL.COM on tue 26 mar 02
In a message dated 3/25/2002 10:42:40 PM Eastern Standard Time,
vpitelka@DTCCOM.NET writes:
> Are you absolutely certain of
> what you used?
>
Hi Vince. Although I cannot claim I am absolutely certain I did question the
contents to make sure that I was using the correct form based on the
recommendation from Australia. My pots stuck to the shelves as if there was
nothing there and many of the bottoms ripped off when I tried to remove them.
Susan
Anne Wellings on wed 27 mar 02
This is getting confusing. In this thread, several different forms of
zirconium silicate are mentioned. Could they all be expected to work in
kiln wash? Why would one person have a disaster with this? My supplier
sells milled zircon. Is that the same as zircon flour? I hope someone can
clarify this, as if this is a good kiln wash, I would like to try it. (My
supplier sells a kiln wash called Z-Tec, and I'm wondering if it's similar.)
Anne
On Tue, 26 Mar 2002 21:10:31 EST, SusanRaku@AOL.COM wrote:
>In a message dated 3/25/2002 10:42:40 PM Eastern Standard Time,
>vpitelka@DTCCOM.NET writes:
>
>
>> Are you absolutely certain of
>> what you used?
>>
>
>Hi Vince. Although I cannot claim I am absolutely certain I did question
the
>contents to make sure that I was using the correct form based on the
>recommendation from Australia. My pots stuck to the shelves as if there
was
>nothing there and many of the bottoms ripped off when I tried to remove
them.
>
>Susan
>
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Tom Buck on thu 28 mar 02
anne w:
ZIRCON is the mineral name for the chemical compound zirconium
silicate, ZrO2.SiO2 (aka ZrSiO4) a crystalline substance. ZIRCON is
sometimes called zircon sand (zircon beach sand). industry wants the
zircon in specific particle sizes, hence the pulverizing and screening
into "flour" etc.
zircopax, ultrox, are tradenames for high-purity zirconium
silicate and they are offered in different size ranges.
if you want a good kiln wash recipe that brushes on smoothly and
lasts, and glaze drips can be removed without too much chipping:
Tom Buck's kiln wash
35 EPKaolin (or any k)
32 Alumina hydrate (trihydrate, Al[OH]3 or Al2O3.3H2O)
17 Kyanite (any mesh, coarser is better)
16 Silica sand (50 mesh or smaller).
mix with water to a coffee cream consistency, and use three brush coats,
one after the other, immediately.
or this one works too:
Rob Tetu's kiln wash
50 alumina hydrate
25 silica sand
25 EPK (or any k)
I use the Kyanite because it is available in 33-35 mesh (like a coarse
grog), and it provides some "roller bearing" action for larger pots.
good pots. Peace. Tom B.
Tom Buck ) tel: 905-389-2339
(westend Lake Ontario, province of Ontario, Canada).
mailing address: 373 East 43rd Street,
Hamilton ON L8T 3E1 Canada
SusanRaku@AOL.COM on thu 28 mar 02
In a message dated 3/28/2002 12:57:03 PM Eastern Standard Time,
Tom.Buck@HWCN.ORG writes:
> Tom Buck's kiln wash
> 35 EPKaolin (or any k)
> 32 Alumina hydrate (trihydrate, Al[OH]3 or Al2O3.3H2O)
> 17 Kyanite (any mesh, coarser is better)
>
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