Hanne Bjorklund on sun 25 apr 99
Re: Tests glazes.
Reply to Margaret Arial.
The key to a successful glaze test lies in precision and an accurate set of
test scales. To be out by one gram is not important in a 10 kg batch, but
in a 100 gr. test it can either spell disaster, or give a misleading
result.
When I began testing, a zillion years ago, I used Weight-watcher scales and
sieved the tests through a fine mesh tea strainer. Don't laugh, I didn't
know any better. When I made up larger amounts, like a whole kilo for my
first little bowls, the fired results were nowhere near the tests I had
made. I found glazing to be totally frustrating, and stopped potting a few
times because there seemed to be no end to my glaze failures.
I have now invested (heavily) in a very accurate set of electronic test
scales, and made myself a great little 100-mesh test sieve from some
plastic pipe connectors and stainless steel mesh.
The scales weigh down to 1/10 of a gram, and there is no more guesswork as
to whether I will be adding I, 1.2 or 1.5 grams of for example cobalt to
a test. I
also use them for weighing out the coloring oxides for 5kg amounts, and
see very little difference between the tests and the pieces I glaze from a
bucket.
I just love my newfangled electronic miracle, it is worth every cent I paid
for it, and wish I had had it 16 years ago.
HANNE
bjorklund@clear.net.nz
Cindy Strnad on sun 28 may 00
Hello everyone.
I just unloaded some glaze tests from the kiln. and was pleasantly rewarded
by all of them, which is definitely a first! Let me share them with you:
I fire to ^6 on a medium speed setting, then soak for 45 minutes. I use a
medium brown ^6 stoneware clay with manganese flecks.
Xavier's Warm Jade Green ^6
Ferro Fr. 3124 9 (I used 3134, but will order some 3124 soon.)
Custer Spar 40
Whiting 16
Talc 9
EPK Kaolin 10
Flint 16
Rutile 6
Add:
Copper Carb 4
Glaze by Heidi Haugen, contributed to Clayart by John Hesselberth
I wouldn't call this glaze a jade green, though jade comes in many colors,
including this one. For me, it produced a beautiful, pale variegated
green-turquoise where thin, and a non-variegated version where thicker. I
liked the thin bits best. Dipping a rather too-large test bowl in a rather
too-small test glaze container makes for a lot of variegations in thickness,
and this added to the interest of the finished surface.
According to the tests John submitted with this glaze recipe, it is
unusually stable for a copper-containing glaze.
Gibby's Wild Rose Tenmoku ^6
This glaze is high on alumina and low on silica. It's also high in lithium.
I wouldn't think it would be suitable for food--it doesn't even look like
something I'd want to eat food from, but it's gorgeous.
Lithium Carb 9.5
Bone Ash 9.5
Neph Syenite 55.7
EPK 15.8
Red Iron Ox. 9.5
Wild Rose fires to a variegated black and metallic copper surface.
Absolutely stunning.
Old Gold Albany
This one is based on a glaze of Marty Anderson, modified, I assume, by Ababy
(who submitted it to Clayart). Another beautiful surface which may not be
food-safe. It's high in lithium and I'm considering having it tested. It
would be nice if it were to pass.
Lithium Carb. 10.0
Zircopax 12.0
Redart 56.2
Whiting 7.8
Custer Spar 6.2
Talc 3.9
EPK 3.9
This glaze turned out satiny matte with areas of dark gold-brown edged by
areas of lighter tan-gold. A lovely smooth, waxy surface. Thanks, Ababy.
Candle Satin Matte, revised.
Chris Schafale shared this glaze, and I've been meaning to try it for quite
some time. I changed it a bit to suit the materials I had on hand. She uses
G-200 spar, I (since I live about 2 miles from Pacer's Custer feldspar mine)
use Custer spar. She uses Frit 3124. I thought I had some of that, but all I
could find was 3134, so I modified the recipe--keeping it as close to the
analysis of her original as I could manage.
Talc 8
Dolomite 8
EPK 23
Silica 6
Custer 37
3134 18
This was advertised as a clear satin matte. Of course, there's no such thing
as a truly clear matte. The very nature of matteness makes this impossible.
It's like a clear frosted window in that regard. It does allow light to come
through, but it obscures what is beyond (or in this case, what is
underneath).
At any rate, it's a beautiful glaze, and may be just what I wanted as a
surface for over-glaze painting. Applied thinly, it's more matte and more
translucent. I'm looking forward to trying out some variations of this
glaze. Thanks bunches, Chris.
Cindy Strnad
earthenv@gwtc.net
Earthen Vessels Pottery
RR 1, Box 51
Custer, SD 57730
Mike Gordon on tue 30 may 00
Cindy,
Are you talking electric? or gas? oxidation or reduction? Mike
Cindy Strnad on fri 20 oct 00
Hi everybody
I've done a bunch of ^10 oxidation glaze tests I'd like to share with =
you. If you think you'll be following this thread, please keep this post =
for reference. There are 30 tests, and, in the interest of keeping =
things as short as possible, I don't want to keep repeating this =
information with each batch of glazes.
First, you'll need to keep all the posts, because the second half of the =
glazes are mixtures of the first half. I may not include recipes for =
this second half. I may just say, this is #16: it's a half and half =
mixture of #s 12 and 7.
Second, each tea bowl (my testers) was incised with an image of a bison =
in the interest of seeing how the glaze would react over carving. So I =
will note something like: Bison fair, bison excellent, bison poor. It =
doesn't mean the glaze is bad, just that it obscured the carving.
If I don't see crazing, pinholing, or crawling, I will note: NVF, which =
is my shorthand for "no visible flaws". I didn't consider slight =
dripping as a flaw, but have noted it in each case where it occurred. I =
haven't tested these glazes yet for crazing under thermal stress, but am =
only making observations of the glaze as it appears shortly after =
cooling from the kiln. These pieces were removed from the kiln at =
approximately 300 degrees F., which is, yes, a little hot, but I had to =
see them, you know.
I'll put up the recipes in batches of five and there are, as I said, 30 =
glazes in all. I haven't yet experimented with additions of color not =
called for in the original recipes.
Cindy Strnad
Earthen Vessels Pottery
RR 1, Box 51
Custer, SD 57730
USA
earthenv@gwtc.net
http://www.earthenvesselssd.com
Cindy Strnad on sat 21 oct 00
Here's another installment in my ^10 glazes. Like the set yesterday, I =
fired
these to ^10 in 9.09 hours in an electric Paragon Viking kiln, which was
allowed to cool naturally to around 300 degrees F. with all holes =
plugged.
They were applied on a blond ^10 stoneware clay.
H GK 92 ^9
Zakin
#6
Custer Feldspar 44
Spodumene 16
EPK 8
Dolomite 18
Zircopax 14
Si:Al 5.61
SiB:Al 5.61
Expansion 6.56
This is an opaque white glaze with a nice fat look. The surface features =
a
soft gloss, almost satin finish. I notice a slight over-all froth which
doesn't quite grade into pinholing. Bison poor.
Gateville Stone 92 ^9
Zakin
#7
Custer Feldspar 30
Spodumene 10
Goldart 30
Dolomite 20
Gerstley 10
Si:Al 4.67
SiB:Al 4.93
Expansion 7.06
For those of you who have Zakin, you may notice I've substituted Custer =
spar
anywhere he calls for any kind of spar. Because of past experiences, I =
doubt
this makes much difference, and as I live in Custer, I feel there's a
certain loyalty issue. Besides, they give me the stuff--as much =
as I
ask for.
Anyway, this glaze surprised me. It was supposed to be stony, and it's =
not.
It called for stoneware clay, and I used Goldart. I thought that was a
stoneware, but maybe I'm mistaken? Or maybe it was underfired at Zakin's
suggested ^9, and mature at ^10.
The glaze is badly crazed, and it would be interesting to know if it was =
my
substitutions that caused the crazing and the (attractive) glossy =
surface.
I'll have to check in Insight. There are tiny bubbles sprinkled =
throughout,
but none of them have reached the surface to cause pinholes or dimples.
Bison prominent.
Gateville R 92 ^9
Zakin
#8
Dolomite 30
Redart 40
Custer Spar 20
Spodumene 10
Si:Al 6.39
SiB:Al 6.39
Expansion 7.12
Beautiful brown to green coloring with lots of downward motion, though =
it
does not seem to be runny--at least not in my moderate application. =
Badly
crazed. Bison prominent.
Franklin R 92 ^9
Zakin
#9
Silica 8
Custer spar 32
Ball clay 8
Redart 22
Dolomite 30
Iron Ox. Red 8
Si:Al 7.16
SiB:Al 7.16
Expansion 7.69
Extremely glossy dark reddish brown to black, breaks a lighter red-brown
with a satin-matte surface at ridges and rim. Attractive blond speckles
throughout. Bison good. NVF.
The amazing thing to me about this glaze is that it hasn't crazed yet. =
I'll
run it through some freeze-boil tests, because I love it, but the =
expansion
is quite high. Even if it doesn't craze, I predict this glaze will never =
be
a big seller because of its dark color. It will also be very difficult =
to
photograph. However, I can use it on some things for myself and my =
friends
and the occasional discerning customer.
Conquest R 92 ^9
Zakin
#10
Spodumene 10
Custer spar 20
Redart 44
Dolomite 6
Gerstley 20
Si:Al 6.57
SiB:Al 7.22
Expansion 7.10
Glossy, variegated dark amber to greenish. NVF. This is a nice glaze, =
but,
to me, boring.
Cindy Strnad
Earthen Vessels Pottery
RR 1, Box 51
Custer, SD 57730
USA
earthenv@gwtc.net
http://www.earthenvesselssd.com
Lewis Crittenden on fri 13 apr 01
It would be helpful if those of you who do a lot of glaze tests would give
a brief description of the type of test tiles you use and an the way you go
about making them. It takes so long to roll clay with a rolling pen and then cut
tiles to the same size. Surely, there must be a simple way of doing it.
Thank you.
--- Lewis Crittenden
--- theoblue44@earthlink.net
--- EarthLink: It's your Internet.
Ababi on fri 13 apr 01
Hello Lewis
I use some kind of test tiles.
To make easier to explain I added a beautiful sketch to my site under
utilities.
1) Is the most favorite you can test the behaving of the glaze in different
structures, there is place to write and it is easy to remove instead , the
glaze floated too much.
2) Is the shape for the extruder.
3)A small saucer, usually done throughing, or hand builders, in a small
disposable plastic saucer. With the kind I use you can make it without
nylon to avoid sticking .
4) This one is the easiest to make, there is a lot of place to write. You
can score it with a fork for texture.
5) This one for raku. the number is scored while preparing. The special
shape is for seeing the behavior of the glaze inside and outside. All the
raku test tiles are one a "carrier, out of Raku claybody with chrome nickel
wires. This way I don't have to remove each test tile alone
6) broken workesׁ
Ababi Sharon
ababisha@shoval.ardom.co.il
http://members4.clubphoto.com/ababi306910/
----- Original Message -----
From: "Lewis Crittenden"
To:
Sent: Friday, April 13, 2001 7:00 AM
Subject: Glaze Tests
> It would be helpful if those of you who do a lot of glaze tests would give
> a brief description of the type of test tiles you use and an the way you
go
> about making them. It takes so long to roll clay with a rolling pen and
then cut
> tiles to the same size. Surely, there must be a simple way of doing it.
>
>
>
> Thank you.
>
>
>
> --- Lewis Crittenden
>
> --- theoblue44@earthlink.net
>
> --- EarthLink: It's your Internet.
>
>
____________________________________________________________________________
__
> 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.
>
debby on fri 13 apr 01
I have been reading clayart for awhile. Now I can share something I
learned!
For test tiles, I make a large pie plate with straight sides about 3 inches
high. I make the bottom part of the wall fairly thick but the rest of the
wall I make my usual pot thickness. I sometimes add finger marks or grooves
in the wall to see how the glaze runs over this. When the clay is leather
hard I slice the plate into 1",2" or 3" pie slices. I cut away the center
of each slice and make sure that each piece has a wide base that can support
it standing up. Then I let these dry and bisque fire them. I try to
always have test tiles around. This is any easy way to get 12 or more at a
time depending on the size of the pie plate you throw.- Debby
>
> It would be helpful if those of you who do a lot of glaze tests would give
> a brief description of the type of test tiles you use and an the way you go
> about making them. It takes so long to roll clay with a rolling pen and then
cut
> tiles to the same size. Surely, there must be a simple way of doing it.
>
>
>
> Thank you.
>
>
>
> --- Lewis Crittenden
>
> --- theoblue44@earthlink.net
>
> --- EarthLink: It's your Internet.
>
> ______________________________________________________________________________
> 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.
Chris Clarke on sat 14 apr 01
Hey,
I throw a wide low cylinder with no bottom to the edge of a bat. Leave a
fat area at the bottom of the cylinder so the tiles stand up. Then to one
side I add rings and texture and the other side I smooth and add a ring of
slip. When it's leather hard I scratch through the slip. Cut the whole
thing up, it makes about twenty five nice wide mice as we called them.
When I'm ready the test, first I put three brush strokes of oxide, cobalt,
copper, and red iron on the back. After I dip it in the glaze I add the
brush strokes to the front on top of the glaze.
No kiln load is without at least one test, I'm obsessed : ) chris
chris@ccpots.com
www.ccpots.com
----- Original Message -----
From: Lewis Crittenden
To:
Sent: Thursday, April 12, 2001 10:00 PM
Subject: Glaze Tests
> It would be helpful if those of you who do a lot of glaze tests would give
> a brief description of the type of test tiles you use and an the way you
go
> about making them. It takes so long to roll clay with a rolling pen and
then cut
> tiles to the same size. Surely, there must be a simple way of doing it.
>
>
>
> Thank you.
>
>
>
> --- Lewis Crittenden
>
> --- theoblue44@earthlink.net
>
> --- EarthLink: It's your Internet.
>
>
____________________________________________________________________________
__
> 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.
Ababi on fri 1 feb 02
In my site, my humble site, I added resolutes of some tests. See if you
like any. There are some recipes too. Page 3 is about one glaze,a
concept, still
working on it
Ababi Sharon
Kibbutz Shoval- Israel
Glaze addict
ababisha@shoval.org.il
http://members4.clubphoto.com/ababi306910/
http://www.milkywayceramics.com/cgallery/asharon.htm
http://www.israelceramics.org/
Sue Clayton on sun 2 mar 03
Thanks for responding, Clayarters.
Ok, I tested three glazes over the pink and purple engobe stains, and a
few other colors. All three -- glossy base 2, glaze B (page 158 Mastering
Cone 6...) and glossy clear liner passed the "fit" test, ie, no crazing, but
the winner in color retention is glaze B. I was surprised. Both glossy
base 2 and glossy clear liner were slightly opaque over the colors, with
glossy clear liner being more opaque than the other. All three caused the
"leaf green" engobe to run, but I did have that on a bit thick.
I subbed wollanstonite for talc in the glossy base 2 recipe, and subbed
custer spar for G-200 in the glossy clear liner. The glaze B did not apply
as smoothly as the other two, but that may have been my application
technique, not the glaze.
I guess the next step is to mix up a bigger batch of glaze B and see what
it does.
-- Sue in snowy Vermont
Ron Roy on mon 3 mar 03
Hi Sue,
Note - glaze "B" is very high in CaO (0.849 in the Seger unity formula) -
that is the part to concentrate on - also see Raspberry - CaO is 0.791.
Sounds like you could develop some limit formulas to get the most out of
your experiments - then you could make those type of glazes out of a
variety of materials.
Be careful now - this sort of thing can be addictive.
RR
>Thanks for responding, Clayarters.
> Ok, I tested three glazes over the pink and purple engobe stains, and a
>few other colors. All three -- glossy base 2, glaze B (page 158 Mastering
>Cone 6...) and glossy clear liner passed the "fit" test, ie, no crazing, but
>the winner in color retention is glaze B. I was surprised. Both glossy
>base 2 and glossy clear liner were slightly opaque over the colors, with
>glossy clear liner being more opaque than the other. All three caused the
>"leaf green" engobe to run, but I did have that on a bit thick.
> I subbed wollanstonite for talc in the glossy base 2 recipe, and subbed
>custer spar for G-200 in the glossy clear liner. The glaze B did not apply
>as smoothly as the other two, but that may have been my application
>technique, not the glaze.
> I guess the next step is to mix up a bigger batch of glaze B and see what
>it does.
> -- Sue in snowy Vermont
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Phone: 613-475-9544
Fax: 613-475-3513
Randy McCall on fri 6 aug 04
I recently fired some Amaco Glazes on Ellen Clay from Highwater to Cone =
6 small cone in a 1027 Skutt. Quick firing with 1 hour on low, 1 hour =
on medium, and 4 hours on high. Cone 05 bisque. Cone sitter just =
shutoff. No slow cool.
PC-20 Blue Rutile=20
Applied 4 coats to each piece.
Got a shiny dull blue, similar to a floating blue but not as nice. =
Nothing that looked like the advertisement. Floating blue, and Opal =
Glazes look better.
PC-30 Tenmmoku
Applied 4 coats to each piece.
Got a black semi gloss opaque with small gold flecks. Nice smooth =
glaze. I like this one. Looked more like a black teadust glaze to me.
PC-35 Oil Spot
Applied 4 coats to each piece.
Got a semi transparent brown glaze that only looked good on a tectured =
piece but where the piece was smooth it was not very impressive.
PC-50 Shino
Brushed on 4 coats as the others, which came out a brownish orange =
fairly opaque. Not impressed by itself, but where it was layered over a =
coat of nutmeg, PC-50, and then a coat of a cream breaking red got a =
nicely variation of browns, reddish brown, and whitish tan colors. Has =
possibilities where layered, but not nice by itself.
PC-60 Salt Buff
Applied one coat out of the jar which was still to thick. Need to cut =
thickness of glaze in half or cut very thin, but has possibilities.
Pompeian Ash Glaze PA 20 Dark Blue
Applied one coat out of the jar, but this was also too thick. Need to =
cut thickness of glaze in half or cut very thin, but has possibilities.=20
Keep in mind your firing schedule may have different results.
Randy McCall
Randy McCall
Rick Bonomo on wed 5 oct 05
October 5, 2005
Click on link or paste URL into address window:
http://www.ricks-bricks.com/images/DiptnSprayed.jpg
Finally got the spray gun hooked up:
(all on Standard 259 at Cone 10 Electric)
From the left:
Best Barium Blue from John Britt's book " High Fire Glazes" - shoulda =
been thicker
A bowl dipped in Nuka glaze =20
Bailey's Red - Had to fire it three times to get the red to come out
After seeing Stephen Hill's pot on the cover of Britt's book I had to =
try it
It's Reitz Green sprayed over Rhodes Stony Matt over John Jelf's Ochre =
Ash 8.5 " tall
That purple thing below it is Perkins Red artificially reduced with =
Silicon Carbide in the glaze
It woulda been redder if I had put a white slip under it as in the small =
test plate
The small brown vase form in the back is John Jelf's Ochre Ash =
artificially reduced
Rick Bonomo
http://www.ricks-bricks.com/recent.htm
http://www.ricks-bricks.com/GlazeRecipes.htm
sacredclay on mon 6 nov 06
I have been doing a few glaze tests. I don't understand what's
happening and unfortunately, I don't have a digital camera to show the
results, so bear with me, please. recipe is as follows
Clear base ^5-6 Oxidation in electric kiln
spodumene----25
F-4----------25
flint--------25
Laguna borate (berstley borate sub--25
add
tit. oxide---4
Three tests done
A) additional tin oxide--1.9 results is a yellowish speckled
rutile-------------------4.9 semi-matte glaze. The granular Illeminte
granular illeminite------1.9 has sunk to the bottom, creating
metallic specks. I really like this glaze and want to develop it more.
B)Red Iron Oxide--14% Nice!surface movements of black/brown/red semi-
gran. Illeminte-1.9 glossy opagque glaze. Almost like Mystic Moss.
C)MaO--2% clear, warm toast and runny. a little white where thick.
My question is, why does gran illemite settles so easily, other than
that it's a heavy compound? It didn't do that in test B.Is it the
rutile that's creating the surface movement?Then can gran. Ille. do the
same? What if I add rutle to test B also? Will it disrupts it more? I'm
trying to understand how the colorants affects the base recipes. I know
that tin is a opacifiersIf I add that to the test C, will it stop it
from being so runny? And how come I don't see anybody use gran illem.
in their recipes, only in clay? Any other comments will be greatly
appreciated. This base recipe is also called L.L. Green, LL.Black, etc.
I don't know what the L.L. stands for. Warmest regards to all, Kathryn
in NC where the trees still glows with colors.
Alisa Liskin Clausen on mon 6 nov 06
On Mon, 6 Nov 2006 14:04:15 -0000, sacredclay wrote:
>I have been doing a few glaze tests. I don't understand what's
>happening and unfortunately, I don't have a digital camera to show the
>results, so bear with me, please. recipe is as follows
>Clear base ^5-6 Oxidation in electric kiln
>spodumene----25
>F-4----------25
>flint--------25
>Laguna borate (berstley borate sub--25
>add
>tit. oxide---4
> Three tests done
>A) additional tin oxide--1.9 results is a yellowish speckled
>rutile-------------------4.9 semi-matte glaze. The granular Illeminte
>granular illeminite------1.9 has sunk to the bottom, creating
>metallic specks. I really like this glaze and want to develop it more.
>
>B)Red Iron Oxide--14% Nice!surface movements of black/brown/red semi-
> gran. Illeminte-1.9 glossy opagque glaze. Almost like Mystic Moss.
>
>C)MaO--2% clear, warm toast and runny. a little white where thick.
> My question is, why does gran illemite settles so easily, other than
>that it's a heavy compound? It didn't do that in test B.Is it the
>rutile that's creating the surface movement?Then can gran. Ille. do the
>same? What if I add rutle to test B also? Will it disrupts it more? I'm
>trying to understand how the colorants affects the base recipes. I know
>that tin is a opacifiersIf I add that to the test C, will it stop it
>from being so runny? And how come I don't see anybody use gran illem.
>in their recipes, only in clay? Any other comments will be greatly
>appreciated. This base recipe is also called L.L. Green, LL.Black, etc.
>I don't know what the L.L. stands for. Warmest regards to all, Kathryn
>in NC where the trees still glows with colors.
>
Dear Kathryn,
I think if you look at the recent glaze tests I posted, you will get an
idea of how colorants affect a clear base.
Obviously, depending on the base, results will be different, but at least
you will see what influences several oxides have on the tested translucent
base of Brian Gartside.
The only surprise was what that the Tin Ox. produceded a harder white than
Zircopax did, which I find to be opposite of the most common results of
these two opacifying oxides when used to whiten a glaze.
Speaking in terms of cone 6 oxidation, how Tin effects your glaze can only
be seen by firing your tests, depending on the percent used, and if other
coloring oxides are present. If you have Chrome present, for example, you
may produce a Chrome Tin Pink if the proportions are conducive to it.
Opacifiers can be tricky, because although we may think of them as
opacifiers and stiffeners, they can also act as fluxes in the same glaze.
You have to work it out in your base.
Rutile often gives movement and a disfussed white "shell" because of it's
Iron and Titanium content. Titanium is good for creating small
crystals.
I think on of the best ways to understand materials is to fire a lot of
tests and record what you are doing. Coloring bases is a solid start to
see how these oxides influence color and surface.
Best regards, Alisa in Denmark
Ron Roy on wed 8 nov 06
Hi Kathryn,
I don't know what MaO is by the way.
That glazes has a realy low expansion - I suggest you try
F4 spar at 53.5
Laguna Borate - at 25.0
Silica at 19.0
Old Mine 4 at 2.5
Total 100 - the expansion will be a much safer level.
If it still runs add clay 5% at a time till it stops.
Illmanite does not work on balanced glazes - they would need to be short of
silica to melt the illamite. - this is not that kind of glaze - leave it
out.
Boron and titanium (Rutil) give that broken look by the way.
Let me know if you have questions.
RR
>I have been doing a few glaze tests. I don't understand what's
>happening and unfortunately, I don't have a digital camera to show the
>results, so bear with me, please. recipe is as follows
>Clear base ^5-6 Oxidation in electric kiln
>spodumene----25
>F-4----------25
>flint--------25
>Laguna borate (berstley borate sub--25
>add
>tit. oxide---4
> Three tests done
>A) additional tin oxide--1.9 results is a yellowish speckled
>rutile-------------------4.9 semi-matte glaze. The granular Illeminte
>granular illeminite------1.9 has sunk to the bottom, creating
>metallic specks. I really like this glaze and want to develop it more.
>
>B)Red Iron Oxide--14% Nice!surface movements of black/brown/red semi-
> gran. Illeminte-1.9 glossy opagque glaze. Almost like Mystic Moss.
>
>C)MaO--2% clear, warm toast and runny. a little white where thick.
> My question is, why does gran illemite settles so easily, other than
>that it's a heavy compound? It didn't do that in test B.Is it the
>rutile that's creating the surface movement?Then can gran. Ille. do the
>same? What if I add rutle to test B also? Will it disrupts it more? I'm
>trying to understand how the colorants affects the base recipes. I know
>that tin is a opacifiersIf I add that to the test C, will it stop it
>from being so runny? And how come I don't see anybody use gran illem.
>in their recipes, only in clay? Any other comments will be greatly
>appreciated. This base recipe is also called L.L. Green, LL.Black, etc.
>I don't know what the L.L. stands for. Warmest regards to all, Kathryn
>in NC where the trees still glows with colors.
>
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Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
sacredclay on fri 10 nov 06
Dearest Ron, I want you to live forever!You are, as well as others, are
providing me with the knowledge that I am looking for. I suspect that
the MaO is manganese dioxide or something like that. You will see in my
later post why I say that. I will subsitute this glaze for the other
one I was doing. So you're saying that a glaze with too low of an
expansion is not safe or stable/ When I leave out the titanium and
just 3% CuCo3, I'd get this beautiful trasparent glossy green that
hasn't given me any problems in the past.No pitting, no scumming, just
a nice durable glaze that's one of my favorite, especially when it has
iron wash under it. And how did you calculate this recipes amount as
well as what materials to use.I wouldn't be pestering you with all of
these questions, but I've found that quite a few of my ceramic and
glaze books have been borrowed after I took them all home.so boron can
be found in what? And it does what? How does it interacts with rutile?
Did the gran. ille. created the surface variegation with RIO in test B?
No, I'm not some puppy out of college. I'm 45 years old woman having a
midlife crisis and glaze explorations is my answer.Induldge me,please!
With the warmest regards, Kathryn in NC enjoying her vanilla hazelnut
tea. No, there's nothing else in it!
Neal on mon 9 apr 07
I mentioned about two weeks ago the test glazes
in my upcoming firing. One was Amaco's Pompeian
ash. I should have looked at the archives
before firing. The glaze was too thick. I'll thin
it before trying it again.
The tests I mixed up were two crawl glazes. I did
not have enough nepheline syenite to do the two
real recipes I had found. So I ended up making just
one of them--Lana Wilson's textured crawl. I subbed
OM4 ball clay for the Kentucky ball.
60 nepheline syenite
22 magnesium carbonate
18 Kentucky ball clay
Lacking enough neph sye for the other recipe, I
ended up adding magnesium carbonate to another
test batch on hand--Tony Hansen's 20x5 clear. I
added magnesium carbonate to prepared glaze.
Lana's glaze was great--just the texture and look
I wanted. It formed small white glassy beads. The
other test wasn't as successful. The glaze crawled
nicely but the beads were dry and looked underfired.
I fire to cone 6 in an electric kiln. All the test
glazes were brushed on. I'll try to take some photos
of the results later.
Neal O'Briant
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