Hank Murrow on thu 27 jul 06
On Jul 27, 2006, at 3:19 PM, mariannekmilks@aim.com wrote:
> Great. Thank you!
> Clarification: Do I start with the first-mentioned four, then add
> parts of the following to small amts of the first mix and test
> those/each? If not, it seems like a super overload of ingredients to
> me, in comparison to recipes I have been reading. Am I correct in
> that?
> I don't know what a Curie Grid tile is, but i will find out through
> Clayart archieves or internet.
The Currie grid tile is discussed at this web site:
http://www.ian.currie.to
Basically, one creates a C corner glaze containing the fluxes to be
studied, then one mixes three additional cups of glaze with varying
amounts of silica and kaolin to see how they melt in relation to those
varying amounts. A typical C corner set of fluxes might be whiting,
feldspar, and dolomite. Say, 30, 30, 40.
>
> How come some glazes are almost exclusively made up of fluxes??
> Example: Slate Blue K-15 Modified by Shannon Nelson. ^6, ox
> neph sy, Dolomite, Silica, EPK, Bone Ash, Lit.Carb, Zinc Oxide.
No wonder you are confused, as the neph sye is not only a flux, but
also includes alumina(stiffener) and silica(glass former), while bone
ash is calcium(a flux) and phosphorus(a glass former).
> Things like this confuse me greatly.
The single thing that will straighten this out in your mind is to think
of all glaze materials as rocks containing minerals which are usually
combinations of elements. Some elements are fluxes, while others are
stiffeners, and still others are glass formers. For most cone 5 glazes,
you will need to balance these materials to come up with a molecular
ratio of 1 flux, to 1/2 to 1 stiffener, to 3 and up to 6 glass former.
What helped me a lot in the early days of my study of glaze was to mark
the buckets of glaze material with a graphic representation of their
molecular composition. I used deep red for the alkaline fluxes, orange
for the alkaline earths, yellow for stiffeners, and blue for the glass
formers. I further represented the molecular ratios for each material
by using colored tape to denote each category. So whiting was a 1"
strip of orange, corresponding to its molecular weight of 100, and its
place as an alkaline earth. Bone ash was represented by an orange strip
2.6" long and a blue strip 1" long to indicate its complement of
calcium (alkaline earth flux) and phosphorus (glass former). Feldspar
was a 1" strip of deep red, a 1" strip of yellow, and a 3.6" strip of
blue. And so on. Just looking at the ice cream containers with their
labels often gave me ideas for combining them, and really helped in my
effort to teach this complex subject. One needs all the help one can
arrange.
cheers, Hank
www.murrow.biz/hank
Hank Murrow on thu 27 jul 06
On Jul 27, 2006, at 8:17 AM, mariannekmilks@aim.com wrote:
>
> My first question still remains: I want to bake a cookie no-one has
> invented.......
> If I would want to make my own unique glaze, which ingredients/group
> do you suggest would be a "must"?
OK Marianne;
First, it is very unlikely that anyone will come up with a glaze that
is new. As many have been forgotten as have ever been invented. That
said, why don't you start with some common materials, add a couple of
ringers for interest, and make some Currie Grid tiles?
My list would include G200 feldspar, nepheline syenite, a kaolin, and
silica. Add the fluxes whiting, dolomite, barium and strontium, and
include the ringers like Low Melt spodumene, petalite, wollastonite,
and a frit or two(suggest an alkaline one and an alkaline earth one).
perhaps zinc and tin as spices and you are good to go. the Currie Grid
tile will let you see the relation between alumina and silica and each
flux or group of fluxes, while revealing several useful glazes on each
tile. I can think of at least twenty likely recipes for C corners that
would yield a lifetime of happy testing(let alone glazing).
Hope you can try it,
Hank
www.murrow.biz/hank
Hank Murrow on fri 28 jul 06
On Jul 28, 2006, at 10:13 AM, Gay Judson wrote:
> Hank, Thanks for the beautiful hint for learning about glaze
> materials (pun
> intended!) Several years ago someone made a similar suggestion--that I
> should label my materials containers so I could learn about the
> materials--but no hint about what the labels should say! So at first
> I had
> the name only. Then added the chemical formula. Then miscellaneous
> notes:
> colorant; feldspar; etc. But it really has not helped me much. But I
> think
> the visual representation using the colored tapes of representative
> lenghts
> will be a great learning tool--if I can figure out how to translate
> molecular weight to length!!
100 mw = 1" worked for me. I had different blue hues for the glass
formers, so boron was light blue, silica was medium blue, and
phosphorus was dark blue.
> A question from an earlier post. You suggested learning to spiral
> wedge
> by closing your eyes while wedging. Dale mentioned that to me earlier
> but I
> don't know what my hands are supposed to be doing--can you put that
> into
> words for me? A verbal message to my hands while wedging.
I suggest pushing forward with the palms and then pulling back with the
fingertips, while keeping the two hands close together.
> Thanks for your many generous contributions to the list!
Aw shucks...............thanks for noticing.
Cheers, Hank
www.murrow.biz/hank
John Post on fri 28 jul 06
Hi Hank,
I believe that Glazchem2 (search google for dinoclay to find glazechem2)
from Robert Wilt will allow you to graph out the components in your
glazes this way. If you wanted to mark you glaze material buckets, all
you would have to do is create a glaze that is 100% Neph Sy. and then
print it in graph form. Then you could tape this on the bucket with
clear mailing tape.
Your idea would make a great teaching tool in a community studio or at
glaze workshops.
John Post
Sterling Heights, Michigan
> What helped me a lot in the early days of my study of glaze was to mark
> the buckets of glaze material with a graphic representation of their
> molecular composition. I used deep red for the alkaline fluxes, orange
> for the alkaline earths, yellow for stiffeners, and blue for the glass
> formers.
Gay Judson on fri 28 jul 06
Hank, Thanks for the beautiful hint for learning about glaze materials (pun
intended!) Several years ago someone made a similar suggestion--that I
should label my materials containers so I could learn about the
materials--but no hint about what the labels should say! So at first I had
the name only. Then added the chemical formula. Then miscellaneous notes:
colorant; feldspar; etc. But it really has not helped me much. But I think
the visual representation using the colored tapes of representative lenghts
will be a great learning tool--if I can figure out how to translate
molecular weight to length!!
A question from an earlier post. You suggested learning to spiral wedge
by closing your eyes while wedging. Dale mentioned that to me earlier but I
don't know what my hands are supposed to be doing--can you put that into
words for me? A verbal message to my hands while wedging.
Thanks for your many generous contributions to the list!
Gay Judson in San Antonio, TX
Lee Love on fri 28 jul 06
On Jul 27, 2006, at 8:17 AM, mariannekmilks@aim.com wrote:
>
> My first question still remains: I want to bake a cookie no-one has
> invented.......
> If I would want to make my own unique glaze, which ingredients/group
> do you suggest would be a "must"?
The best way to make a glaze now one else has every made is by
digging around your neighborhood. Use ash from your fireplace or
the fire place of your neighbors.
Natural materials, instead of ones refined for industry, are
always going to be more "unique."
I am using some Goto Maki and Mogusa clay, clays that were
tradtionally used for shino and oribe. Both of these clays have a
lot of organic material. Even green, they are lighter than pots made
of "normal" clay. When they are fired, the organics fire out and
they become lighter and porous. We asked how "open" Goto Maki was
and the guy at Akechi said: "It will leak after it is fired."
Mogusa is the same name given to the plant used in moxibustion.
If you find some native clay, just screen out the rocks and use
it as it is. It will be unique compared to refined materials.
Lee in Mashiko, Japan
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