Tracey Dobbins on sun 23 aug 98
-------------------
Who has a favorite white crackle raku glaze that they'd like to share as one=
of
the all time best white crackles??? What temp and consistancy? Am trying a
bunch of test glazes and wonder if there's any out there that I haven't =
tried
yet=21=21=21=21 Ha=21
Much thanks...
Marvin S. Flowerman on tue 25 aug 98
You ought to try this Barium White Crackle at cone 08:
Gerstley Borate (in absence of colemanite) 60 grams
Buckspar (K-200) 50 grams
Barium Carbonate 22 grams
Silica 16 grams
This was originally one of the studio glazes at the Raritan Valley Community
College in Somerville, New Jersey; it works consistantly well with good
crackle and good crackle difinition.
Let me know how it works for you please.
Marvin Flowerman
William Q Hynes on tue 25 aug 98
Here's my favorite raku crackle white, used here at Shippensburg U.
8 lbs. Gerstley Borate
2 lbs. Custer Feldspar
add to the above 10 lb. batch: 10% Zircopax
We fire this glaze to 1850 F. in a two burner gas raku kiln. Very
consistant results. Nice crackles....
hope this helps,
cookie
On Sun, 23 Aug 1998, Tracey Dobbins wrote:
> ----------------------------Original message----------------------------
> -------------------
> Who has a favorite white crackle raku glaze that they'd like to share as one o
> the all time best white crackles??? What temp and consistancy? Am trying a
> bunch of test glazes and wonder if there's any out there that I haven't tried
> yet!!!! Ha!
>
> Much thanks...
>
Milton Markey on tue 25 aug 98
Hi Tracey!
The following are two recipies Alan Meisel, a Professor, Dept. Chairman (now
retired), and for me, a role model, in the art of ceramics, created for the
raku class at Laney College, in Oakland, CA. If you want a white crackle
glaze, don't add Copper Carbonate to the M. Blue mixture. You may want to
experiment with the opacifier, to produce a "whiter" white (sounds like a
laundry detergent commercial!).
Meisel Blue (Raku)
Frit 3110 100% (Note: this is correct!)
Tin Oxide 10%
Kaolin 5%
add: Copper Carbonate 1%
Notes: This glaze coagulates quickly. If a batch of it is allowed to stand for
a long time, let the contents dry completely, then add 1-2% bentonite, then
introduce water. Be sure to stir this glaze well before applying. When firing,
be sure the ware is "white hot" before pulling it from the kiln. Smoke the
ware thoroughly (10-15 minutes). Do not place the ware in water to facilitate
a "quick cool-down" after reduction smoking.
Also, Alan provided the Raku students with this white crackle glaze:
Meisel White Raku Glaze
Frit 3110 100% (Try it, you'll like it!)
Kaolin 5%
Gerstley Borate 10%
CMC Gum 1%
ZircoPax 10%
Note: Although I tested this glaze on a chip, I never applied it to a pot
(white is not a personal color of choice). Let me know what your results are!
By the way, Alan inspired the students by challenging us to improve upon his
glazes, and experiment, test, and experiment and test once more! I guess I got
my knack for experimenting and trying unorthodox combinations of glazes and
raw materials from him. The first thing he'd ask me, when I arrived at the
studio, is "do you want the coffee grounds (from the studio perculator)?" I
usually answered, with a grin, "this may be grounds for dismissal!"
There you go!
Milton MiltonsLin@AOL.COM
MRS SANDRA L BURKE on wed 26 aug 98
Meisel,
I was wondering if it is possible to get a crackle glaxe in an
electric kiln. I've tried several variations but no luck yet.
Anyone else have any sugestions?
Sandy Burke
Judith Enright on thu 27 aug 98
>----------------------------Original message----------------------------
>Meisel,
>I was wondering if it is possible to get a crackle glaxe in an
>electric kiln. I've tried several variations but no luck yet.
>Anyone else have any sugestions?
>Sandy Burke
I haven't tried this one myself, but it was published on Clayart sometime
in '97. Recipe says it's good for oxidation or redux:
Cornwall stone 85 %
Whiting 15%
Good luck!
Judith Enright @ Black Leopard Clayware
Charlie and Linda on thu 27 aug 98
MRS SANDRA L BURKE wrote:
>
> ----------------------------Original message----------------------------
> Meisel,
> I was wondering if it is possible to get a crackle glaxe in an
> electric kiln. I've tried several variations but no luck yet.
> Anyone else have any sugestions?
> Sandy Burke
Dear Sandy
I frequently use Middlebrooks Crackle White in the electric kiln. Pull
at 06-04 and then reduce. It will be REALLY crackled if you spray a
little compressed air on it. (I just use my air from the spray booth.
My mustash is in better shape now that I'm not trying to blow on the hot
pots!)
Charlie Riggs
Judith Enright on thu 27 aug 98
As an addendum to the Cornwall Stone/Whiting recipe (oxid. or redux) for the
clear crackle I posted earlier: This is a ^9-10 glaze, and should be applied
thickly.
Judith
----------
From: "MRS SANDRA L BURKE"
Sent: Wednesday, August 26, 1998 9:27 AM
To:
Subject: Re: Favorite raku white crackle?
----------------------------Original message----------------------------
Meisel,
I was wondering if it is possible to get a crackle glaxe in an
electric kiln. I've tried several variations but no luck yet.
Anyone else have any sugestions?
Sandy Burke
This email may contain confidential and privileged material for the sole use of
Tom Buck on thu 27 aug 98
Sandy B: Most of us try to avoid crackle on our foodware, and often
the reason we do get crackle stems from too much sodium oxide in the
recipe. You do not mention the cone you fire to, I'm assuming midfire, so
to get crackle on a pot, use your current recipe and add Ferro Frit 3110
in increasing amounts til you get crackle.
You could use Soda Ash to obtain the Sodium Oxide but then face
its recyrstallization in the glaze mix, and would therefore have to
fresh-mix a new glaze batch weekly. Also, to use Soda Ash you may have to
bisque to a higher cone, and thereby lower the porosity so less Soda Ash
goes into the claybody.
Good tests.
Tom Buck ) tel: 905-389-2339
& snailmail: 373 East 43rd St. Hamilton ON L8T 3E1 Canada
(westend Lake Ontario, province of Ontario, Canada).
On Wed, 26 Aug 1998, MRS SANDRA L BURKE wrote:
> ----------------------------Original message----------------------------
> Meisel,
> I was wondering if it is possible to get a crackle glaxe in an
> electric kiln. I've tried several variations but no luck yet.
> Anyone else have any sugestions?
> Sandy Burke
>
Andrew Buck on thu 27 aug 98
Sandy,
Glazes crackle due to the glaze shrinking, as the pot cools, more than the
clay that the glazed item is made of. The type of kiln the piece is fired
in should not make any difference. In an electric kiln though, there is
not the reducing atmosphere required to darken the clay through the
crackles. You may be getting crackles in the glaze and not seeing them.
Try rubbing some ink on the pots, and if there are crackles, the ink may
darken them when it is rubbed off the surface.
Andy Buck
Raincreek Pottery
Port Orchard, Washington, USA
On Wed, 26 Aug 1998, MRS SANDRA L BURKE wrote:
> ----------------------------Original message----------------------------
> Meisel,
> I was wondering if it is possible to get a crackle glaxe in an
> electric kiln. I've tried several variations but no luck yet.
> Anyone else have any sugestions?
> Sandy Burke
>
Charlie and Linda on fri 28 aug 98
Andrew Buck wrote:
>
> ----------------------------Original message----------------------------
> Sandy,
>
> Glazes crackle due to the glaze shrinking, as the pot cools, more than the
> clay that the glazed item is made of. The type of kiln the piece is fired
> in should not make any difference. In an electric kiln though, there is
> not the reducing atmosphere required to darken the clay through the
> crackles. You may be getting crackles in the glaze and not seeing them.
> Try rubbing some ink on the pots, and if there are crackles, the ink may
> darken them when it is rubbed off the surface.
>
> Andy Buck
> Raincreek Pottery
> Port Orchard, Washington, USA
>
> On Wed, 26 Aug 1998, MRS SANDRA L BURKE wrote:
>
> > ----------------------------Original message----------------------------
> > Meisel,
> > I was wondering if it is possible to get a crackle glaxe in an
> > electric kiln. I've tried several variations but no luck yet.
> > Anyone else have any sugestions?
> > Sandy Burke
> >
Mr. Buck is correct about no difference in glaze firing in electric
kilns vrs gas kilns.......if you gas kiln fires in a neutral atmosphere
at all times. My raku kilns don't. Unlike most, they are in oxidation
until 1700F. Many of my friends kilns fire in reduction atmosphere due
to excess fuel or too small of a flue or.....
Many raku glazes will violently boil if fired in certain levels of
reduction or oxidation(in my case, too much oxidation) which can cause a
glaze to have pin holes, cratering, or mottling of the color.
Though I uses this effect to achieve certain styles there are many other
times when a smooth unbroken surface and uniform color is desired.
Instead of constantly monitoring a gas kiln to keep in in "neutral" I
use an electric kiln and obtain consistant results.
Contrary to what I thought in the past, the electric kiln survives quite
a long time if used to raku. I purchase and old used kiln and rakued
hundreds of times with little deterioration and never replaced the
elements(yes it began to slow down a bit toward the end....firing to 06
went from 1:15 to 1:30 elapsed time in a 5 cu. foot kiln.) I then gave
the kiln to a student who continued using it to fire to cone 6.
My new Skutt 1027 arrived yesterday in the middle of hurricane Bonnie
and is awaiting it's first round of electric raku firing. Can you guess
what I've named it? Why you are right!!! How did you guess!!? It's
going to be know as "Frank". No offence to the Bonnie's of the world.
Have fun electric rakuing. Please be cautious. Always turn the kiln
off or you just might kill yourself if you bump the elements with those
metal tongs!!! 240 volts can teach you to jig if you live through it.
Charlie Riggs
In Carthage where Bonnie was all talk and NO action.(thank goodness)
MRS SANDRA L BURKE on fri 28 aug 98
Tom,
I wanted to use the crackle glaze on some sculptural pieces, so I'm
not concerned with food contamination. I tied several glazes at cone
04 and a few at cone 6. All were supposed to be crackle formulas.
Some of them were very nice white to off white, but none of them
crackled. I even tried pulling them while the kiln was still hot.
Sandy
MRS SANDRA L BURKE on fri 28 aug 98
Judith,
What cone do you fire this to?
Thanks
Sandy B
Joy Holdread on sat 29 aug 98
> I wanted to use the crackle glaze on some sculptural pieces, so I'm
> not concerned with food contamination. I tied several glazes at cone
> 04 and a few at cone 6. All were supposed to be crackle formulas.
> Some of them were very nice white to off white, but none of them
> crackled. I even tried pulling them while the kiln was still hot.
> Sandy
>
You may have crackles but you don't see them. With Raku the smoke works it's
way in. Heat the pot up in an oven or outdoors in the sun, about too hot to
handle, brush on India ink or a thinned latex paint, rub off the surface & let
us know what you find.
Joy in Tucson.
MRS SANDRA L BURKE on sun 30 aug 98
Joy,
I did try that, unfortunately it didn't work---there just aren't any
cracks to show up.
Possibly the rate of fire??????? I do fire the kilns VERY slowly as
it is filled mostly with student work.
Sandy Burke
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