Jeff Lawrence on wed 27 mar 02
Les H was recommending the 50:50 kaolin:silica recipe
for kiln wash
Hi Les,
I applaud your application method but this recipe is a
poor choice for long firings. I also find that sooner or
later it always flakes, whether thin or thick.
Ian Currie diagnosed a problem in my crystalline
glaze firings where beautiful platters would leave half
their footring behind on the shelves, freshly washed
with the warhorse 50:50 recipe. Apparently the silica
in the wash can and did react with the clay in the footrings.
This problem disappeared when I went to a silica-free recipe,
alumina hydrate:kaolin 80:20 per a Ron Roy (?) suggestion.
The zircon flour mix ought to be even more stable, since
it has less kaolin and no hydrate to burn off. Des's comment
about his shelfs made it sound like it doesn't flake off
at all.
If there's one thing I hate more than grinding wash off
old shelves, it's finding a flake embedded in the glaze of
an otherwise nice pot.
Jeff Lawrence
jml@cybermesa.com
Les Haworth on wed 27 mar 02
Susan, Being a lab tech at a local college for three years gave me some
great experiences. One of my first lessons was to make up kiln wash. The
recipe is 50% EPK. 50% Silica 200 mesh. My way of application may not go
over too well with some potters but it works for me. I like to mix my kiln
wash Very, Very thin. A bit thinner than cream to be exact. After allowing
the kiln wash to slake for a day I remix and adjust as needed to
consistency. At this point I line up my shelf's and get out my super fast
kiln wash applicator. (a paint roller and pan!) I apply a thin coat in the
vertical direction. wait till dry (no longer than 5 min.) Then apply a coat
in the horizontal direction. Allow to dry 5 min. If wash does not dry in 5
min. then you've put it on too thick. Remove wash with water and allow to
dry then start over. Either thin out wash or apply thinner coats. The key is
a thin coat in one direction and another thin coat in the opposite
direction. Take a moist sponge and clean all kiln wash from the sides of
your shelf's, then your done. Try this old standard instead of using zircon
flower. It works!!! Les H.
Lester R. Haworth III
Sales and Technical Support
Laguna Clay Co.
14400 Lomitas ave
City of Industry, CA 91746
1(800) 4-LAGUNA ext. 229
(626)330-0631 ext. 229
les@lagunaclay.com
www.lagunaclay.com
"The title of Artist is self-proclaimed!" Les H.
-----Original Message-----
From: Ceramic Arts Discussion List [mailto:CLAYART@LSV.CERAMICS.ORG]On
Behalf Of SusanRaku@AOL.COM
Sent: Monday, March 25, 2002 10:44 AM
To: CLAYART@LSV.CERAMICS.ORG
Subject: Re: [CLAYART] : kiln wash recipe
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
>
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Les Haworth on thu 28 mar 02
Your probably using silica 325 mesh in your kiln wash recipe instead of 200
mesh. Also if your concerned about flakes add 10% Alumina hydrate to the
recipe and that should take care of the problem. Les H.
Lester R. Haworth III
Sales and Technical Support
Laguna Clay Co.
14400 Lomitas ave
City of Industry, CA 91746
1(800) 4-LAGUNA ext. 229
(626)330-0631 ext. 229
les@lagunaclay.com
www.lagunaclay.com
"The title of Artist is self-proclaimed!" Les H.
-----Original Message-----
From: Ceramic Arts Discussion List [mailto:CLAYART@LSV.CERAMICS.ORG]On
Behalf Of Jeff Lawrence
Sent: Wednesday, March 27, 2002 9:23 PM
To: CLAYART@LSV.CERAMICS.ORG
Subject: Re: [CLAYART] :The best kiln wash recipe
Les H was recommending the 50:50 kaolin:silica recipe
for kiln wash
Hi Les,
I applaud your application method but this recipe is a
poor choice for long firings. I also find that sooner or
later it always flakes, whether thin or thick.
Ian Currie diagnosed a problem in my crystalline
glaze firings where beautiful platters would leave half
their footring behind on the shelves, freshly washed
with the warhorse 50:50 recipe. Apparently the silica
in the wash can and did react with the clay in the footrings.
This problem disappeared when I went to a silica-free recipe,
alumina hydrate:kaolin 80:20 per a Ron Roy (?) suggestion.
The zircon flour mix ought to be even more stable, since
it has less kaolin and no hydrate to burn off. Des's comment
about his shelfs made it sound like it doesn't flake off
at all.
If there's one thing I hate more than grinding wash off
old shelves, it's finding a flake embedded in the glaze of
an otherwise nice pot.
Jeff Lawrence
jml@cybermesa.com
____________________________________________________________________________
__
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
melpots@pclink.com.
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