Jeff Tsai on fri 24 may 02
Russel Wrote:
"WHAT IS THIS GLAZE and where do those crystals come from."
here's the site:
http://www.billboydceramics.com/blue_crackle_bowl_blowup.htm"
Since there was no question mark, I don't know if Russel's question was
rhetorical or not, but I know I've seen similar glazes, so I looked it up.
As
far as I can tell, it looks like a extremely high feldsepathic glaze.
A very similar glaze is pictured in Ian Currie's book "Using the Grid
Method"
on page 83. I'd give the recipe, but I don't know if there's copyright
infringment or not, but the recipe is in that same book on page 82. It's
pretty simple and is mostly feldspar.
-Jeff
Russel Fouts on fri 24 may 02
I was cleaning out mail and ran across an old email from Rod & Erin"
<2rediron@home.com> that included a like to Canadian Bill Boyd's site.
This is the best closeup picture I've ever seen of this glaze.
http://www.billboydceramics.com/blue_crackle_bowl_blowup.htm
To revive the a discussion from Nov of 2001
I've seen this glaze occasionally, actually included an example by
Shimizu Uichi on my site a while ago to show what it looks like.
WHAT IS THIS GLAZE and where do those crystals come from.
Shore is purdy!
Ru
--
Russel Fouts
Mes Potes & Mes Pots
Brussels, Belgium
Tel: +32 2 223 02 75
Mobile: +32 476 55 38 75
Email: Russel.Fouts@Skynet.be
Http://www.mypots.com
http://www.Japan-Net.ne.jp/~iwcat
"There is a theory which states that
if ever anyone discovers exactly what
the universe is for and why it's here,
it will instantly disappear and be
replaced by something even more bizzarly
inexplicable."
"There is another theory which states
that this has already happened!"
Douglas Adams' The Hitch Hiker's Guide to the Galaxy
Jocelyn McAuley on fri 24 may 02
Hi Russel,
This is exactly the crackle patter we get from our "Chinese Crackle" glaze
at University of Oregon:
Cone 10 Chinese Crackle
Kingman 83%
Whiting 9%
Silica 8%
--------------
100
zircopax 10%
This glaze really settles out, so I'd definitly add 2% bentonite. It
yields a milky white feldsparic crackle (circular rosette patterns) that
seems really popular as a glaze on chinese import ceramics right now.
I think it would accept colorants well. The zircopax is for if you want
white.
Enjoy!
--
Jocelyn McAuley ><<'> jocie@worlddomination.net
Eugene, Oregon http://www.ceramicism.com
Russel Fouts on sat 25 may 02
Jocelyn,
That sort of fits with what en evasive potter here said when I asked him
about a very similar glaze. He would only say that it was a very high
feldspar glaze. High is right. ;-)
Anybody have any idea what is happening in this glaze? Why the
"crystals" form the way they do?
Russel
Jocelyn McAuley wrote:
>
> Hi Russel,
>
> This is exactly the crackle patter we get from our "Chinese Crackle" glaze
> at University of Oregon:
>
> Cone 10 Chinese Crackle
>
> Kingman 83%
> Whiting 9%
> Silica 8%
> --------------
> 100
> zircopax 10%
>
> This glaze really settles out, so I'd definitly add 2% bentonite. It
> yields a milky white feldsparic crackle (circular rosette patterns) that
> seems really popular as a glaze on chinese import ceramics right now.
> I think it would accept colorants well. The zircopax is for if you want
> white.
>
> Enjoy!
>
> --
> Jocelyn McAuley ><<'> jocie@worlddomination.net
> Eugene, Oregon http://www.ceramicism.com
--
Russel Fouts
Mes Potes & Mes Pots
Brussels, Belgium
Tel: +32 2 223 02 75
Mobile: +32 476 55 38 75
Http://www.mypots.com
http://www.Japan-Net.ne.jp/~iwcat
"There is a theory which states that
if ever anyone discovers exactly what
the universe is for and why it's here,
it will instantly disappear and be
replaced by something even more bizzarly
inexplicable."
"There is another theory which states
that this has already happened!"
Douglas Adams' The Hitch Hiker's Guide to the Galaxy
Lee Love on sat 25 may 02
----- Original Message -----
From: "Jeff Tsai"
> http://www.billboydceramics.com/blue_crackle_bowl_blowup.htm"
> on page 83. I'd give the recipe, but I don't know if there's copyright
> infringment or not, but the recipe is in that same book on page 82. It's
> pretty simple and is mostly feldspar.
Boycott copyrighted glaze recipes. ;^)
If you look at the first shino at this page, a nezumi (blue/gray) shino,
you'll
see the same quartz crystals: http://www1.ocn.ne.jp/~ikiru/jshino.html
This
bowl makes me think that some chuns and blue shinos are very similar. We
know
they were both primarily made of feldspar.
If you apply the chun below thickly, and cool slowly (on a white body), you
get
similar crystals. Use this glaze. It won't look the same as when I use
it.
Paul's Chun Cone 10 & higher. Reduction.
Custer 80
Whiting 7
Flint 7
Softwood ash 4
Bone Ash 2
Yellow Ochre 1
Bentonite 1
For purple splash: 3% copper slip on raw body.
Lee in Mashiko
"The lyfe so short, the craft so long to learne." - Geoffrey Chaucer
(c.
1340-1400).-
._____________________________________________
| Lee Love ^/(o\| Practice before theory.
|
| Ikiru@hachiko.com |\o)/v - Sotetsu Yanagi - |
`~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~'
"All weaves one fabric; all things give
Power unto all things to work and live." - Goethe -
Jeff Tsai on sat 25 may 02
Hi Russel,
If you meant me, I wasn't trying to be evasive, I've learned to be careful
though.
If you had been standing in the room next to me, I would've opened the book,
written down the recipe and given it to you, but, ya know, recent talks
about
glaze copyrights make me sketchy on doing that over the internet now.
I don't know why the glaze forms such interesting crystal patterns and
crazes, but in Curries book, the glaze is called a "guan or Kuan glaze" What
that means, GOt me. is it helpful, again, got me. But it's a place to start
looking. Hamer's dictionary has no listing for these types of glazes (at
least not under the two names I've seen). Maybe a serach of the internet
might bring up more information.
-jeff
iandol on sun 26 may 02
Though I can' remember reading the original post on this one, the idea =
of "Quartz Flake" rang a bell when I read the recipe.
First, Quartz Flake. There is a Mine up in the Caldbeck Fells in the =
North of England which exploited the mineralisation of a massive quartz =
vein. All the waste quartz was pure white and translucent. Larger =
cobbles of the stuff could be "Knapped" as in striking a "Flint" so it =
was possible to tap thin super sharp flakes.
There is an illustration In Greg Daly's glaze book of a pot which had =
been fired with a very thick coating of felspar as the only glaze =
ingredient. This has the same white translucent character and superb =
crackle. No actual crystals.
In the recipe which is given, it is possible for the silica and whiting =
to combine creating Wollastonite, if it is a fact that there are =
discrete crystals in the glaze. This can be a solid state reaction which =
will happen before felspar gets hot enough to commence working as a =
solvent flux. If firing is prolonged, some crystals can grow larger at =
the expense of smaller crystals.
Interesting stuff. I wonder where it fits on an Ian Currie Grid?
Ivor Lewis=20
iandol on sun 26 may 02
Dear Jeff Tsai,
Lots of discussion over several months about giving recipes. One point =
which came out was that, in general, a recipe carries no copyright =
prohibition.
About Guan Glazes. Ch 4 of "Chinese Glazes" by Nigel Wood gives the good =
oil and excellent illustrations together with sample recipes. These seem =
to Celadons with wide crazing.
Best regards,
Ivor Lewis
Lee Love on sun 26 may 02
----- Original Message -----
From: "Jeff Tsai"
> , the glaze is called a "guan or Kuan glaze" What
> that means, GOt me. is it helpful, again, got me. But it's a place to
start
> looking. Hamer's dictionary has no listing for these types of glazes (at
> least not under the two names I've seen). Maybe a serach of the internet
> might bring up more information.
My post might have given a clue. :^) Look up Chun in
Hamer's.
Lee in Mashiko
"The lyfe so short, the craft so long to learne." - Geoffrey Chaucer
(c.
1340-1400).-
._____________________________________________
| Lee Love ^/(o\| Practice before theory.
|
| Ikiru@hachiko.com |\o)/v - Sotetsu Yanagi - |
`~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~'
"All weaves one fabric; all things give
Power unto all things to work and live." - Goethe -
iandol on tue 28 may 02
Dear Ian,=20
Thanks for confirming my suspicions. I suspect these work better at =
higher temperatures. I saw something similar to your description in one =
of the new Home and Kitchen supply stores and wondered about the regular =
periodic circular medallion structure of the crazing which had a much =
closer structure than the glazes shown on the illustrations in Nigel =
Wood's book. Thought they might have induced it via thermal shock with =
an oxy torch.
Great to have you back writing for us again.
Best regards,
Ivor
Lee Love on tue 28 may 02
There is a potter here in Mashiko and all his work is done in this type of
glaze
(except it is brown and not blue.) He calls the effect rice grain
crystals.
He fires the work using the yohen method, which means heavy recduction using
charcol. I don't know if he pours the charcol in at the end of the firing
or
if he fires in saggars, with the work packed in charcol.
--
Lee In Mashiko, Japan Ikiru@hachiko.com
"We can only wait here, where we are in the world, obedient to its
processes,
patient in its taking away, faithful to its returns. And as much as we may
know, and all that we deserve of earthly paradise will come to us."
Wendell Berry , Full Quote: http://www1.ocn.ne.jp/~ikiru/berry.html
Ian Currie on tue 28 may 02
> Interesting stuff. I wonder where it fits on an Ian Currie Grid?
> Ivor Lewis
Hi Ivor
I've not heard this term before, Quartz Flake Crackle, but I think I know
what it is, going on what I've picked up from this thread. I suspect the
name is slightly confusing, as the glaze is usually mostly feldspar or
nepheline syenite... 80 to 90%. There is usually some whiting and some
silica - e.g. 10% of each.
I have heard this glaze called Lux Flake... I call it Snowflake Crackle (see
photo and details on pages 82, 83 of "Revealing Glazes" (available from my
web site below). There is also a Kuan experiment in my other book,
"Stoneware Glazes - A Systematic Approach" that picks up these glazes near
the high feldspar corner. See page 180
It is essentially a Kuan or Guan type glaze. But on the clay bodies we use,
instead of the 2 or 3 dramatic craze lines typical of the old Chinese Guan,
there are masses of concentric crackles. The effect requires that the
glaze be applied THICKLY, or you just get fairly normal crazing. I also
suspect it is fired a bit higher and quicker than the Chinese Guan... and is
not quite so opaque.
And regarding its location of the grid Ivor, it's close to or actually
Corner C (glaze 31) in most high feldspar sets, as long as the glaze is
applied thickly enough. There is usually no kaolin or other clay in the
glaze and if there is 10% of silica that puts it into glaze 32 or very
close.
I suspect the "quartz flake" terminology might come from the fact that the
glaze (like most or all glass?) has a conchoidal fracture (shell-like)...
convex chips that when making up the body of a crazed glaze give that
interesting 3-D depth typical of this glaze.
Regards
Ian
http://ian.currie.to/
Ian Currie on sat 1 jun 02
Hi Lee
I found your posting (below) interesting. Especially the bit about the
"rice grain crystals". If we are still talking of Kuan or Guan type glazes
I might have something here. Bearing in mind all the usual disclaimers,
especially when trying to imagine a glaze from a romantic Japanese name...
After fossicking around through my old tests I pulled out the sets used for
Chapter 22 "Kuan Glazes" in my book "Stoneware Glazes - A Systematic
Approach". I found a couple of granular crystalline glazes there. Not the
ones that give the "snowflake crackle" I mentioned in the last post I made
on this thread. The crystals need more whiting. At least 20% in this
experiment.
And the most granular texture was on a tile that was overfired. Most of the
glazes were too transparent to be called Kuan.
The sample that was most granular had 70% Potash feldspar, 20% Whiting, 10%
Silica. A simple glaze recipe but there are LOTS of qualifications... the
glaze must be VERY thick, fired relatively high (please don't ask! local
fauna sometimes make inroads into precious stuff... but around cone 10 in a
long firing.) And if you don't get it right you have another boring
overfired high feldspar glaze. However the granular crystals show some
promise, and would probably require slow cooling.
Can't comment on the place of the yohen firing.
Regards
Ian
http://ian.currie.to/
> From: Lee Love
> Reply-To: Lee Love
> Date: Tue, 28 May 2002 06:30:05 +0900
> To: CLAYART@LSV.CERAMICS.ORG
> Subject: Re: Quartz Flake Crackle
>
> There is a potter here in Mashiko and all his work is done in this type of
> glaze
> (except it is brown and not blue.) He calls the effect rice grain
crystals.
> He fires the work using the yohen method, which means heavy recduction
using
> charcol. I don't know if he pours the charcol in at the end of the
firing
> or
> if he fires in saggars, with the work packed in charcol.
>
> --
> Lee In Mashiko, Japan Ikiru@hachiko.com
>
> "We can only wait here, where we are in the world, obedient to its
processes,
> patient in its taking away, faithful to its returns. And as much as we
may
> know, and all that we deserve of earthly paradise will come to us."
> Wendell Berry , Full Quote: http://www1.ocn.ne.jp/~ikiru/berry.html
>
>
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