Lois Ruben Aronow on mon 27 dec 99
I am begging the good graces of clayarters and the glaze gurus on this
one. Can anyone help me bring this glossy clear ^9 ox down to a ^6? I
have tried with Insight, but am probably not experienced enough with
this task. I have tested and tested to no avail.
Happy hols to all....Lo
Custer feldspar 20
Nepheline syenite 15
Whiting 20
Talc 10
China clay 15
Quartz 20
Frit 3195 10
Bone ash 2
Manganese dioxide 0.15
Red iron oxide 0.8
Edouard Bastarache on tue 28 dec 99
------------------
Hello,
Hal McWhinnie( i hope i spelled it right) wrote in
Ceramics Monthly many years ago that you can
lower a c/9-10 glaze to c/6 by:
1-Substituting for Potash Spar by Nepheline/Syenite,
2-Adding 10=25 Gerstley Borate
I hope the extra B2O3 will not cause any glaze flaw.
There is nothing like testing.
Later,
Edouard Bastarache
edouardb=40sorel-tracy.qc.ca
http://www.sorel-tracy.qc.ca/=7Eedouardb/
-----Message d'origine-----
De : Lois Ruben Aronow =3Cgilois=40earthlink.net=3E
=C0 : CLAYART=40LSV.UKY.EDU =3CCLAYART=40LSV.UKY.EDU=3E
Date : 27 d=E9cembre, 1999 19:48
Objet : Cone 9 glaze into a cone 6: Can you help?
=3E----------------------------Original message----------------------------
=3EI am begging the good graces of clayarters and the glaze gurus on this
=3Eone. Can anyone help me bring this glossy clear =5E9 ox down to a =5E6? =
I
=3Ehave tried with Insight, but am probably not experienced enough with
=3Ethis task. I have tested and tested to no avail.
=3E
=3EHappy hols to all....Lo
=3E
=3ECuster feldspar 20
=3ENepheline syenite 15
=3EWhiting 20
=3ETalc 10
=3EChina clay 15
=3EQuartz 20
=3EFrit 3195 10
=3EBone ash 2
=3EManganese dioxide 0.15
=3ERed iron oxide 0.8
Ron Roy on wed 29 dec 99
Hi Lois,
You will need to test these of course cause I'm making it up again. I used
frit 3134 for good reason. 3195 has a lot of alumina - 3134 has none so I
can get more clay into the bucket - a good idea when you are using neph sy.
Do 500 grams of each - plus your colours - apply them to two sets of tiles
or pots and fire both sets in the same kiln but in different locations -
with large cone 6's beside them. Mix variation A with C to get B.
Revision A
Custer - 17.0
Neph Sy - 8.0
Whiting - 17.0
Talc - 9.0
EPK - 19.0
Silica - 17.0
F3134 - 11.0
Bone Ash - 2.0
MnO2 - 1.3
Red Iron - 0.7
Total 102.0
Expansion is about the same as the origional but I guess you are going to
be using a cone 6 clay so you will need to keep an eye open for any fit
problems.
Ratio is about the same as well so I guess this may be about the same gloss.
Revision C
Custer - 15.0
Neph Sy - 7.0
Whiting - 15.0
Talc - 8.0
EPK - 20.0
Silica - 15.0
F3134 - 18.0
Bone Ash - 2.0
MnO2 - 1.3
Red Iron - 0.7
Total 102.0
Again the expansion and ratio are about the same as the original - letme know
If they work - if they don't I can do more but I need to see the test tiles
so you will have to send them to me.
How long did this take me? About half an hour - if it was my first one it
would have taken half a day I guess.
RR
>----------------------------Original message----------------------------
>I am begging the good graces of clayarters and the glaze gurus on this
>one. Can anyone help me bring this glossy clear ^9 ox down to a ^6? I
>have tried with Insight, but am probably not experienced enough with
>this task. I have tested and tested to no avail.
>
>Happy hols to all....Lo
>
>Custer feldspar 20
>Nepheline syenite 15
>Whiting 20
>Talc 10
>China clay 15
>Quartz 20
>Frit 3195 10
>Bone ash 2
>Manganese dioxide 0.15
>Red iron oxide 0.8
Ron Roy
93 Pegasus Trail
Scarborough
Ontario, Canada
M1G 3N8
Evenings 416-439-2621
Fax 416-438-7849
Paul Taylor on thu 30 dec 99
Dear Ruben
What is frit 3195.
I will suppose it to be a borax fritt.
I am going to deal with this using dead reckoning because I lack exact info.
Do not forget that not only are you using a different body, or not
fluxing the one you normally use as much, the glaze body layer will not be
the same. It is also easy to imagine that just adding more flux will melt a
glaze. This is not necessarily so. Some chemicals only preform well at cone
8 + and the reactivity of chemicals changes expidentually as the temperature
climes. Cone 8-10 seems to be a temperature that a lot of ceramics like.
Stepping away from this temperature the rules change ;so that although
trying to adjust a glaze down is not difficult, the caricaturistics of the
glaze may be lost due to different fluxes becoming predominant.
Firstly I will tidy the recipe into % with the coloring oxides left
out.
Feld 18
N syenite 13.
whiting 18
Talk 9
cc 13.
Quarts 18
frit 9
bone 2
The first thing to increase is the fritt since it is a fair bet that it
melts well and will not upset the balance of the glaze. Be generous.
make fritt 18 -try that first it may be enough.
But here is your difficulty. Calcium and magnesium tend to form mats -
depending on amounts and then run all over the place after a certain temp.
So Increasing the calcium or the talk will probably not have the desired
effect at cone six. Even the amounts you have may tend not to flux to a
clear glaze, but into a mat crystal at cone 6. So you may have to decrease
the amount of talk and or calcium. Calcium does strange things at amounts
greater than 12 % it is either mat or all over the kiln shelves. Talk makes
nice smooth mats at just a little above the quantity you are using.
Increasing the soda and (potash) by increasing the N syenite to 20
and decreasing the feld by 10 will help flux the glaze but will probably
craze it. As an alternative to that I would use Lithia in the form of
Petalite or spodemine instead ( but that may poison a few. I am not
convinced, but there is a discussion on it in the archive) I would
substitute a lithium feldspar for some of the custer.
You could loose 3 parts of the china clay with out doing much harm
Have you noticed how complicated this is getting. How many variables
there are in this balancing act to deal with? Is this glaze worth it? What
are it's special qualities are they that important that a published cone 6
glaze won't do? So many constituents of this glaze will need changing to get
near the right effect. You could do better starting again adding the bone
ash and coloring oxides .
The coloring oxides may not behave quite the same at cone 6 but you
are better to
leave them as they are.
So try this----- dose not add up to 100 but it fits with the coloring
oxides.
N syenite 15
Custer 9
petelite/spodemine 6
Whiting 18
talk 9
cc 13
Quarts 18
Fritt 18
bone 2
+ coloring oxides
After deliberating over the changes and doing a couple of half
hearted test I would probably give up , or find out what exactly is in that
fritt and try substitutions on a chemical level . There are people on this
list that like to deal with glazes this way and seem to be very good.
Going down three cones is more complicated than it seems. And it
is a bit much to expect to take your glazes with you. Because of the high
temperatures it is difficult to believe that such a small difference can not
be made up for, so who can blame us for trying .
Paul T
----------
>From: Lois Ruben Aronow
>To: CLAYART@LSV.UKY.EDU
>Subject: Cone 9 glaze into a cone 6: Can you help?
>Date: Tue, Dec 28, 1999, 12:54 am
>----------------------------Original message----------------------------
>I am begging the good graces of clayarters and the glaze gurus on this
>one. Can anyone help me bring this glossy clear ^9 ox down to a ^6? I
>have tried with Insight, but am probably not experienced enough with
>this task. I have tested and tested to no avail.
>
>Happy hols to all....Lo
>
>Custer feldspar 20
>Nepheline syenite 15
>Whiting 20
>Talc 10
>China clay 15
>Quartz 20
>Frit 3195 10
>Bone ash 2
>Manganese dioxide 0.15
>Red iron oxide 0.8
Lawrence Ewing on thu 30 dec 99
Hi Lois,
I am currently working on some tutorials for users of Matrix Glaze
Calcuation Software and am about to start on a tutorial dealing with the
task of changing the maturing temperature of a glaze.
Would you mind if I used the glaze you published with a request for help in
lowering the maturing temperature?
I would call the glaze Lois's C.9 to preserve your anonimity.
All of the Matrix tutorials are accessible by everyone on the internet so
you could have a look at the tutorial when it is finished.
Looking forward to hearing from you, Happy New Year
Lawrence Ewing
Senior Lecturer
Ceramics Department
School of Art
Otago Polytechnic
Dunedin
New Zealand
email: lewing@clear.net.nz
MATRIX URL's:
http://www.tekotago.ac.nz/art/matrixgoweb/default.htm
http://home.clear.net.nz/pages/Matrix2000
GLAZETEACH URL:
http://home.clear.net.nz/pages/GlazeTeach
MATRIX TUTORIALS:
http://home.clear.net.nz/pages/lewing/MatrixTutorials
-----Original Message-----
From: Ceramic Arts Discussion List [mailto:CLAYART@LSV.UKY.EDU]On Behalf
Of Lois Ruben Aronow
Sent: Tuesday, December 28, 1999 1:54 PM
To: CLAYART@LSV.UKY.EDU
Subject: Cone 9 glaze into a cone 6: Can you help?
----------------------------Original message----------------------------
I am begging the good graces of clayarters and the glaze gurus on this
one. Can anyone help me bring this glossy clear ^9 ox down to a ^6? I
have tried with Insight, but am probably not experienced enough with
this task. I have tested and tested to no avail.
Happy hols to all....Lo
Custer feldspar 20
Nepheline syenite 15
Whiting 20
Talc 10
China clay 15
Quartz 20
Frit 3195 10
Bone ash 2
Manganese dioxide 0.15
Red iron oxide 0.8
Lois Ruben Aronow on fri 31 dec 99
> Hi Lois,
>
> I am currently working on some tutorials for users of Matrix Glaze
> Calcuation Software and am about to start on a tutorial dealing with the
> task of changing the maturing temperature of a glaze.
>
> Would you mind if I used the glaze you published with a request for help in
> lowering the maturing temperature?
>
> I would call the glaze Lois's C.9 to preserve your anonimity.
I'd like to give credit where credit is due. This glaze comes from Takeshi
Yasuda, and was published in Ceramics Review about 1994 or 5. My only hand in
it was changing the chemicals from british to American, as it originally called
for FFF Feldspar and P2957 frit.
I am a big fan of Mr. Yasuda's work, particularly the sansai influenced. This
particular clear has a nice glow and moderate crazing, and I am hoping to get
something similar to use on my ^6 grolleg porcelain. The glaze is usually used
on stoneware, so this is an interesting exercise for me in testing, etc.
Since posting this, I have received much help from the clayarters (MUCH
THANKS!!) and have learned alot about the glaze and the way it works. I am
deeply grateful for the generosity of those here.
Merry Millennium all, and may the kiln gods and goddesses be with those who are
firing tonight.
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