marianne kuiper milks on wed 19 jul 06
Dear Hank,
What a gift you all are. Wayne added much to what I didn't get, but this is what I have been looking for most. It makes sense-at least in the way my mind works. (slowly, with many gyrations)
I am going to start playing and writing and calculating and not be afraid to "do it wrong". Now I have a tangible start.
Thank you so much! I'm sure more questions will come forth...
Marianne
Hank Murrow wrote: On Jul 19, 2006, at 10:14 AM, marianne kuiper milks wrote:
> OK. Have a good laugh.
> I took Glaze Calculation at Alfred last year from Bill Carty. Learned
> a TON.
> Read. Studied the manual. Took a glaze class (GlazeMaster) from John.
> Lili has answered MANY, many questions.
> But there is still one very basic one I do not understand and it is
> driving me (more) crazy.
>
> HOW does one know WHICH ingredients?
> Why use G200 instead of whatever?
Oh my God, Marianne;
I have been waiting for this question for years! Well, it all depends
upon what you are looking for in a glaze. For example, if you are
looking for green from copper, there must be some barium or strontium
in the glaze, and probably some talc for the magnesia, and a mix of
potassium and sodium feldspars (your G200 and Neph Sye). And you will
likely need small amounts of zinc, whiting, gerstley Borate and clay.
Add 2.5% copper carbonate for the color. Copper just won't likely make
that lovely green color unless it is in a base such as I have
described. Now for copper blues, you will want that G200 spar
again(perhaps 60%), with lots (30%) of barium, and some clay (kaolin,
so the color will be pure) and zinc (I find that zinc helps to promote
the oxidized form of the copper). Say, 5% each. throw in 3_4% copper
carbonate and you are on your way. Even copper yellow is not
unreachable if you can fire to cone 10 Oxidation. Start with Neph Sye
at 75%, and add 5% each of Dolomite and Whiting, another 5% kaolin, 2%
zinc (see above), and round it out with 8% silica. Finally add 1.5%
copper carb for the elusive color. Must be on a very white body and not
too thick, and not too thin....touchy thing this copper yellow.
So you can see how as the base changes, the color response from copper
will change. Now throw in the atmosphere in the kiln.......all those
glazes are likely to go livery or red, depending on how melty they
are........ no greens or blues, let alone yellow.
If you were looking for a durable surface for dinnerware, your search
would concentrate on whiting, potassium feldspar, kaolin, and silica,
perhaps some talc as well. Wollastonite would be a good addition. What
you are looking for will drive your choices.
I know you are probably asking by now, "But Hank, how do you know what
makes these colors/changes/surfaces?" My answer is, "the collective
experience/theorizing/speculation of generations of potters and
chemists, some of whom have written their results down........ leavened
(since you have a gift for metaphor) with my own considerable
experience trying to achieve these colors and others."
And that's the Truth, as I see it.
Cheers, Hank
www.murrow.biz/hank
www.murrow.biz/hank
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Hank Murrow on wed 19 jul 06
On Jul 19, 2006, at 3:15 PM, marianne kuiper milks wrote:
> Dear Hank,
>
> What a gift you all are. Wayne added much to what I didn't get, but
> this is what I have been looking for most. It makes sense-at least in
> the way my mind works. (slowly, with many gyrations)
> I'm sure more questions will come forth...
Dear Marianne;
My teacher, Robert James, used many metaphors to try to bridge the gap
between glass theory and the experiences college students might have
had. Among them were the cooking ones, which are especially happy ones.
You know of course, of the marvellous marriages of basil/tomato,
fennel/halibut, chocolate/late harvest grenache, lamb/rosemary, etc.
Well, glaze colors are like that too. Among potters, one never hears of
turquoise, one hears of 'copper' blue, nor indian red but iron red, nor
shiny red but copper red. Chuns betray their Chinese origins in the
name, and are also called iron blues. Maija Grotell used to say(to my
teacher, "You can get any color that an oxide is in nature to make that
color at any temperature with that oxide in a glaze." I don't know
about any temperature, but I am pretty sure she was correct at cone 10.
The colors I have seen, sometimes in error, often surprise me; and
would never have surprised her. My teacher studied with her.
Write your questions down on 3x5 cards and keep them near your laptop.
Cheers, Hank
www.murrow.biz/hank
Jacqueline Miller on wed 19 jul 06
Marianne: So glad you asked this question. I am testing the base which
is just 85% cornwall stone and 15% whiting. Couldn't be easier unless
you could find one with only one ingredient (I think they call it
Amaco). On my porcelain at cone 10 gives a very nice feeling
translucent gloss surface. I have no idea about "stability" it just
seems to fit the body well. On a cone6 body it crazes and gives nice
crazing effects for none food-use items.
I am starting to add colorants to see what I get. I will post some
tests when they are done. Jackie
On 7/19/06, Hank Murrow wrote:
> On Jul 19, 2006, at 3:15 PM, marianne kuiper milks wrote:
>
> > Dear Hank,
> >
> > What a gift you all are. Wayne added much to what I didn't get, but
> > this is what I have been looking for most. It makes sense-at least in
> > the way my mind works. (slowly, with many gyrations)
> > I'm sure more questions will come forth...
>
> Dear Marianne;
>
> My teacher, Robert James, used many metaphors to try to bridge the gap
> between glass theory and the experiences college students might have
> had. Among them were the cooking ones, which are especially happy ones.
> You know of course, of the marvellous marriages of basil/tomato,
> fennel/halibut, chocolate/late harvest grenache, lamb/rosemary, etc.
> Well, glaze colors are like that too. Among potters, one never hears of
> turquoise, one hears of 'copper' blue, nor indian red but iron red, nor
> shiny red but copper red. Chuns betray their Chinese origins in the
> name, and are also called iron blues. Maija Grotell used to say(to my
> teacher, "You can get any color that an oxide is in nature to make that
> color at any temperature with that oxide in a glaze." I don't know
> about any temperature, but I am pretty sure she was correct at cone 10.
> The colors I have seen, sometimes in error, often surprise me; and
> would never have surprised her. My teacher studied with her.
>
> Write your questions down on 3x5 cards and keep them near your laptop.
>
> Cheers, Hank
> www.murrow.biz/hank
>
> ______________________________________________________________________________
> 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.
>
--
Jackie Miller
JackieAMiller@gmail.com
Ivor and Olive Lewis on thu 20 jul 06
Dear Hank Murrow ,
I was taken by this quotation <<... Maija Grotell used to say(to my =
teacher), "You can get any color that an oxide is in nature to make that =
color at any temperature with that oxide in a glaze."...>>
So, have you ever encountered a bright vivid Pink when using one of the =
manganese chemicals in a glaze. I ask because I have worked with two =
Manganese minerals, Rhodonite and Rhodocrosite. I have achieved a violet =
hue but more frequently the colour in stoneware glazes is yellow ochre =
to a deep rich golden honey. Recently I have attained what might be =
termed a rich dark weak Red Umber. But so far, no Pink.
As for Marianne's question. I'm still thinking about what she asks.
Best regards,
Ivor Lewis.
Redhill,
South Australia.
Hank Murrow on thu 20 jul 06
On Jul 20, 2006, at 12:12 PM, Ivy Glasgow wrote:
> There are so many variables
> that go into a glaze .......snip.......... really, why can't I have=20
> one base glaze for all colors and all seasons??
For the same reason that basil tastes great on tomatoes, but is not the=20=
best choice for sweet potatoes. Use an analogy from your own=20
experience. For example, cobalt in modest amounts in a high magnesia=20
matt glaze will yield fine magenta-pinks, but get more silica in the=20
glaze to gloss it out and the cobalt will be shiny strong blue. Or=20
switch the flux to sodium and boron and the blue will turn a greenish=20
blue. Just the way glaze develops color. We don't complain about all=20
the variables of green when trees start to leaf out, so why should=20
colors in glazes and glass be all the same?
>
> For instance, copper. Hank posted a great analysis, but some of the=20
> things
> in it conflict with the info I have, or what I have observed. For=20
> example-
> My references state that barium or strontium in copper glaze add a =
blue
> color, and that for the deepest greens it is necessary to use lead=20
> (I'm not
> gonna go there) or zinc.
And I say that those examples are at very different temperatures and I=20=
was talking only about matt glazes fired in oxidation at cone 10.
> But no explanation of the glaze chemistry beyond
> that... Yet, other references state that a copper glaze high in sodium=20=
> will
> be bluer, and one high in magnesium will be faded... How does it all =
go
> together???
When magnesia is introduced to a matt copper blue, it goes towards=20
green......jade green, not Oribe green. Interestingly, when you break=20
open one of those matt copper blues, it is copper red just under the=20
surface. So you can see why we go a little crazy at times trying to=20
understand. Yet, like the mountains, we try because they are there.
>
> , but, gees, shouldn't that be in the book?
> Yes!
> I also think that there's no point in twisting a formula so far out
> of stability that it will yield a copper yellow- isn't that what iron,
> rutile, and yellow stains are for?? Why can't I have one base glaze=20
> for all
> colors and all seasons??
I did not twist a recipe to create copper yellow. Nor do I overvalue=20
'stable' glazes. This one appeared sporadically among the copper reds I=20=
was working with, and I finally tried it in oxidation and Voil=E0! There=20=
it was. It is very touchy, and worth the trouble to me. There is no=20
combination of iron and/or titanium that has given me this color,=20
that's why I called it copper yellow instead of pumpkin, or some such.=20=
You may see it here:
http://www.murrow.biz/hank/images/b-pix/b010.jpg and here:
http://www.murrow.biz/hank/images/b-pix/b021.jpg
No need to tear out your hair Ivy, just take good notes and spend as=20
much time looking at your results as you do mixing and firing them.
Cheers, Hank
www.murrow.biz/hank
Elizabeth Priddy on thu 20 jul 06
For instance, copper. Hank posted a great analysis,
but some of the
things
in it conflict with the info I have, or what I have
observed. For
example-
My references state that barium or strontium in copper
glaze add a blue
color, and that for the deepest greens it is necessary
to use lead (I'm
not
gonna go there) or zinc. But no explanation of the
glaze chemistry
beyond
that... Yet, other references state that a copper
glaze high in sodium
will
be bluer, and one high in magnesium will be faded...
How does it all go
together???
_____________________________
Add this component into your equation. The presence
or lack of oxygen during firing is another chemistry
component, as in raku copper glazes. That wild
flashing color only happens at just the right
temperature and just the right amount of oxygen
allowed before reduction occurs. The difference
between oxidation firings and reduction firings is all
about the chemistry of how oxygen comes into play and
when.
So the AIR, just the plain old air, will affect the
surface results of a copper flashing glaze. The green
raku baskets are the same glaze as the bowl raku 1-4
on my init pics page. And the olny difference is the
order I pulled them from the firing and the amount
they cooled down before they hit identical reduction
chambers.
Good thing that glaze is cool no matter what it turns
out as and I don't get hung up on what to expect out
of raku.
The dark blue crawly glaze there on the blue pots is
the same glaze as the blue on the grid plates. Just a
matter of thickness of application, pulled within a
minute of each other and into identical reduction
chambers. I kept notes and can repeat it at will, as
long as I hold my tongue at just the right angle, but
I am amazed at the variegation I got from basicly five
glazes in the whole body of crit work. I used a raku
blue, a raku copper flashing, a white a black and
clear.
So no kidding, there are micro-factors that affect
glazes such that to demand that they be codified in a
book rather than in an artists personal memory is
asking a bit more than the format allows.
But an architect just might be the person for the job.
Still not ready to devote a lifetime to glaze
chemistry, too much else to do first.
E.
Elizabeth Priddy
Beaufort, NC - USA
http://www.elizabethpriddy.com
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Hank Murrow on thu 20 jul 06
On Jul 19, 2006, at 11:48 PM, Ivor and Olive Lewis wrote:
>
> I was taken by this quotation <<... Maija Grotell used to say(to my
> teacher), "You can get any color that an oxide is in nature to make
> that color at any temperature with that oxide in a glaze."...>>
>
> So, have you ever encountered a bright vivid Pink when using one of
> the manganese chemicals in a glaze.
No Ivor, I seldom use Manganese, yet I wonder what atmosphere prevails
in your fires for pink. Usually, I try for pink with cobalt.
Cheers, Hank
www.murrow.biz/hank
Ivy Glasgow on thu 20 jul 06
I'm with Marianne in the confused department. There are so many variables
that go into a glaze and it seems like so many of them are not completely
documented or the documents are contradictory. I have spent a lot of this
year in wrist braces, so I using my down time to read glaze books, over and
over again. I am using my up time on glaze testing. And I STILL don't get
it! Like, really, why can't I have one base glaze for all colors and all
seasons??
For instance, copper. Hank posted a great analysis, but some of the things
in it conflict with the info I have, or what I have observed. For example-
My references state that barium or strontium in copper glaze add a blue
color, and that for the deepest greens it is necessary to use lead (I'm not
gonna go there) or zinc. But no explanation of the glaze chemistry beyond
that... Yet, other references state that a copper glaze high in sodium will
be bluer, and one high in magnesium will be faded... How does it all go
together???
Here's another example. I mixed up an approximation of MC6G's "Spearmint"
color, but didn't like the hue of yellow-green that resulted (dirty
rutile!). So I thought I'd add a little chrome. An unexpected muddy brown
resulted, apparently from the chrome reacting with titanium... I searched to
find a reference to support this and found almost nothing. In one of my
glaze books, I finally found a picture of an orangy-brown test tile that
states it contains chrome and titanium, but does not document the base glaze
or the amount of chrome added. The adjacent tile says it is a chrome
opacified with tin. No pink at all, just a muddy green. Why? It's a
*mystery*?! We can't learn anything from this without the base glaze
formula. I'll email the author and see if he can help, but, gees, shouldn't
that be in the book?
My personal opinion? I think that there's very little "mystery" in glaze
colors that could not be solved with some careful experimentation and
documentation. Transportability be darned, chemistry is still chemistry, the
world around. I also think that the artists who write these books seem to
have very little concept of scientific method, and treat chemistry like
voodoo. I also think that there's no point in twisting a formula so far out
of stability that it will yield a copper yellow- isn't that what iron,
rutile, and yellow stains are for?? Why can't I have one base glaze for all
colors and all seasons??
And if that rant signs me up to write the darn book, well, then, so be it.
In the meantime I will be in my dungeon testing, testing, testing, testing,
testing, and alternately tearing out my hair.
Ivy G., still thinking like an architect
Ivor Lewis wrote:
I was taken by this quotation <<... Maija Grotell used to say(to my teacher),
"You can get any color that an oxide is in nature to make that color at any
temperature with that oxide in a glaze."...>>
So, have you ever encountered a bright vivid Pink when using one of the
manganese chemicals in a glaze. I ask because I have worked with two Manganese
minerals, Rhodonite and Rhodocrosite. I have achieved a violet hue but more
frequently the colour in stoneware glazes is yellow ochre to a deep rich golden
honey. Recently I have attained what might be termed a rich dark weak Red Umber.
But so far, no Pink.
As for Marianne's question. I'm still thinking about what she asks.
Ivor and Olive Lewis on fri 21 jul 06
Dear Hank Murrow,=20
Sorry to disappoint you but I have never recorded Pink from a manganese =
glaze. Only once have I had a Violet and that came out of a Seger Cone 8 =
electric kiln at Sunderland College of Art. At that time I was not =
making glazes, we used the ready mades and just added colouring oxides.
But if Maija Grotell was correct in her assertion then Pink must be =
possible since there are pink Manganese Minerals. Yes, there is a Pink =
Cobalt mineral.
Best regards,
Ivor Lewis.
Redhill,
South Australia.
John Hesselberth on fri 21 jul 06
On Jul 20, 2006, at 3:12 PM, Ivy Glasgow wrote:
> I think that there's very little "mystery" in glaze
> colors that could not be solved with some careful experimentation and
> documentation. Transportability be darned, chemistry is still
> chemistry, the
> world around. I also think that the artists who write these books
> seem to
> have very little concept of scientific method, and treat chemistry
> like
> voodoo. I also think that there's no point in twisting a formula so
> far out
> of stability that it will yield a copper yellow- isn't that what iron,
> rutile, and yellow stains are for?? Why can't I have one base glaze
> for all
> colors and all seasons??
Hi Ivy,
First be my/our guest at being the person to sort all this out and
turn it into hard reproducible science. Lots of very smart people
have spent decades of their lives over the last century or two trying
to do just this and weren't able to complete the job. It wasn't for
lack of trying or for lack of understanding and using the scientific
method. But hopefully you will succeed.
What I think you are missing is the complexity of the system. For
example we are not dealing with simple chemistry. It is extremely
complex chemistry. But even worse it is not 'just chemisty'-- is a
combination of chemistry and physics. Color depends on the
reflectance and transmittance of light and that in turn depends not
just on chemistry but crystal forms, crystal sizes, thickness of the
light path, and probably several more things I have skipped over.
Then there is the impurity of our raw materials. We are not dealing
with simple college chemistry lab systems. And of course there are
other variables in the system that are not totally controllable
without using systems so expensive we could not afford them.
Those of us who have a scientific or engineering background usually
enjoy sorting through all these variables and learning bits and
pieces about how they work together (or not). But if your frustration
level gets too high I would suggest switching to using stains--they
are a bit more predictable (though also more 'uninteresting' in my
opinion). They are manufactured materials where quality and
consistency has been controlled to a significant degree. And they
have been put into a form where they interact less with the glaze
'soup'. In a simplified way they are just particles of color
suspended in the glass. Or if your frustration gets really high maybe
you should taking up oil painting. There you can mix blue and yellow
and get green. Sorry, you can't do it with glazes.
In the meantime good luck on your quest. We will enjoy hearing of
your progress.
Regards,
John
Alisa Liskin Clausen on fri 21 jul 06
>
>Here's another example. I mixed up an approximation of MC6G's "Spearmint"
>color, but didn't like the hue of yellow-green that resulted (dirty
>rutile!). So I thought I'd add a little chrome. An unexpected muddy brown
>resulted, apparently from the chrome reacting with titanium... I searched
to
> >
>My personal opinion? I think that there's very little "mystery" in glaze
>colors that could not be solved with some careful experimentation and
>documentation. Transportability be darned, chemistry is still chemistry,
the
>world around. >
>And if that rant signs me up to write the darn book, well, then, so be it.
>In the meantime I will be in my dungeon testing, testing, testing,
testing,
>testing, and alternately tearing out my hair.
>
>Ivy G., still thinking like an architect
>
>
Dear Ivy
Unfortunately, choosing to work in ceramics does not entitle one to hard
and fast, undisbutable knowledge.
Why does Chrome become brown with an opacifier, or why does Nikkel and
Zinc produce pinks and blues, or, or. There are absolutely (chemistry)
reasons for why they will but there are absoulutely reasons for why they
will not. Sometimes the reason for why they did not require more
understanding than the reason for why they succeeded.
And yes, that has to do with other materials they are reacting with.
Which ones, how much, kiln atmosphere. I do not think you should be
frustrated that it is not all in black and white. How could it be? There
are always variations, exceptions, one-offs and it is not voodoo.
I am personally offended by the following comment as it is shafes my
tolerance for bad behavior and arrogance. John Britt, John Hesseberth, Ian
Currie, Ron Roy, Tom Buck, Hamer and Hamer, etc. are not witch doctors.
You are eager to learn but also seem to want promised results in the form
of written instructions.
you wrote:
I also think that the artists who write these books seem to
>have very little concept of scientific method, and treat chemistry like
>voodoo. I also think that there's no point in twisting a formula so far
out
>of stability that it will yield a copper yellow- isn't that what iron,
>rutile, and yellow stains are for?? Why can't I have one base glaze for
all
>colors and all seasons??
One base glaze for all seasons? In a sense you can. You just need to
learn how to adjust it, and by adjusting it for all seasons, you will
learn all of the chemicals and all of their effects and relationships they
have with all of the other materials, in all of your kiln atmospheres, on
all of your clay types. Along the way, you will also learn to adapt for
different batches of the same chemical perhaps coming from different
sources in the world. After you are reasonably comfortable with all of
that, you can try to begin to work with effects not expected or ever
encountered before, but it did happen and cannot necessarily be repeated.
Nothing voodoo, but for instance you had a crystal of glaze in your bucket
because the glaze got cold, that you did not notice and it gave you an
interesting effect on your glaze surface. Not too big of a job for
anyone! I suppose all this is part of the reason there are a lot of
people writing a lot of books. I, honestly, look forward to yours.
Best regards from Alisa
Ivy Glasgow on fri 21 jul 06
Hey, I've just learned more from these messages than from a stack of
glaze books. Thanks a million, Clayarters. I still don't completely
get it but the light might be beginning to appear. Thanks John for
reminding me that color is not just chemistry, it's crystals and
reflectance and refraction. Thanks Hank for leading me to the photos
of your awesome "copper yellow" glaze. I might not call it yellow
myself but it is breathtakingly lovely! And thanks E for the
explanation & links to your raku work. Lots to think about, lots more
real world stuff to take into account.
Come to think of it, my dad is a retired ceramics engineer. I am sure
I got my mindset of looking for the "logical, repeatable, stable, no-mystery"
glaze from him. Perhaps I can sic him on the glaze color issues. He is
always looking for something to occupy humongous amounts of his time
and his mind, show off his knowledge, drive him to distraction, and
amaze friends and family. My FIL is a soon to be retired engineer
who focuses on exotic alloy experiments. So if we can get them together,
mwahahaha...
Meanwhile, it's back to the dungeon for me. Test, test, test, and come
up for air. To see what I got in the last round, check out my blog
at ivyglasgow.com. For this round, I have acquired a very
"mysterious" secret formula for an Egyptian Blue glaze that was used
commercially in the 20's and 30's by a prominent art pottery.
Formula looks kinda weird to me, but, the photos are beautiful,
so I'll try to be philosophical and say, what do I know at this point. I
wasn't going
to mess with it, but in the spirit of me being more openminded, why not throw a
few grams of materials at it and see what happens? I am curious to see
what the glaze gurus here think of this formula, too.
Here it is as it came to me:
Egyptian Blue
Soda ash 62
Whiting 21
Feldspar 111
Silica 24
Add Copper Oxide 18
I believe it is supposed to be a cone 04 formula.
The dungeon calls...
-Ivy G.
> On Jul 20, 2006, at 3:12 PM, Ivy Glasgow wrote:
>
> > I think that there's very little "mystery" in glaze
> > colors that could not be solved with some careful experimentation and
> > documentation. Transportability be darned, chemistry is still
> > chemistry, the
> > world around. Why can't I have one base glaze
> > for all
> > colors and all seasons??
Hank Murrow wrote:
>For the same reason that basil tastes great on tomatoes, but is not >the
>best choice for sweet potatoes. Use an analogy from your own
>experience. For example, cobalt in modest amounts in a high magnesia
>matt glaze will yield fine magenta-pinks, but get more silica in the
>glaze to gloss it out and the cobalt will be shiny strong blue. Or
>switch the flux to sodium and boron and the blue will turn a greenish
>blue. Just the way glaze develops color. We don't complain about all
>the variables of green when trees start to leaf out, so why should
>colors in glazes and glass be all the same?
--- In clayart@yahoogroups.com, John Hesselberth wrote:
> What I think you are missing is the complexity of the system. For
> example we are not dealing with simple chemistry. It is extremely
> complex chemistry. But even worse it is not 'just chemisty'-- is a
> combination of chemistry and physics. Color depends on the
> reflectance and transmittance of light and that in turn depends not
> just on chemistry but crystal forms, crystal sizes, thickness of the
> light path, and probably several more things I have skipped over.
> Then there is the impurity of our raw materials. We are not dealing
> with simple college chemistry lab systems. And of course there are
> other variables in the system that are not totally controllable
> without using systems so expensive we could not afford them.
>
> Those of us who have a scientific or engineering background usually
> enjoy sorting through all these variables and learning bits and
> pieces about how they work together (or not).
E wrote:
>The dark blue crawly glaze there on the blue pots is
>the same glaze as the blue on the grid plates. Just a
>matter of thickness of application, pulled within a
>minute of each other and into identical reduction
>chambers. I kept notes and can repeat it at will, as
>long as I hold my tongue at just the right angle, but
>I am amazed at the variegation I got from basicly five
>glazes in the whole body of crit work. I used a raku
>blue, a raku copper flashing, a white a black and
>clear.
Ivy Glasgow on fri 21 jul 06
--- In clayart@yahoogroups.com, Alisa Liskin Clausen wrote:
> Dear Ivy
> Unfortunately, choosing to work in ceramics does not entitle one to hard
> and fast, undisbutable knowledge.
>
> I am personally offended by the following comment as it is shafes my
> tolerance for bad behavior and arrogance. John Britt, John Hesseberth, Ian
> Currie, Ron Roy, Tom Buck, Hamer and Hamer, etc. are not witch doctors.
> You are eager to learn but also seem to want promised results in the form
> of written instructions.
Let me clarify my rant: I may not be working from the best books, and I
would certainly appreciate recommendations! I don't intend any slam on
authors who carefully document their work and present it in a sensible way.
My complaint is with the outright sloppiness of method & presentation that
I have observed in several of the books I'm working with. Things like
showing a picture of a glaze, with no formula. Or throwing out a bunch of
formulae without having tested them or photographed them. Or calling a
formula "food-safe" without test results or instructions as to limits
of the oxides that can be put into it. Showing a test tile of an
obviously unintentionally crawling or crazed glaze and calling it a
great glaze. If I am paying for a book that someone has taken the time
and effort to publish, I *do* expect better "written instructions" than
that, and I think everyone should!
That being said, I haven't read any of the authors you mention except for JH
and RR's MC6G. That's a mighty fine book, and my only problem with it is
that there's not enough of it. Hey guys, how about a volume 2, with a focus
on color development?
I am so far working with:
Rhodes' "Clay and Glazes for the Potter" 3rd ed.
Burleson's "Ceramic Glaze Handbook" 2nd ed.
Bailey's "Glazes Cone 6"
Cooper's "The Potters Book of Glaze Recipes"
Robin Hopper's "The Ceramic Spectrum"
and "Mastering Cone 6 Glazes".
Any suggestions for more enlightening resources would be greatly
appreciated. Even at $40 a pop, if it saves a couple hours of
hair-tearing, it's more than worth it.
-Ivy G.
Daniel Semler on fri 21 jul 06
Hi Ivy,
Books. Hmmm... I have a bunch on glazing.
>
> I am so far working with:
> Rhodes' "Clay and Glazes for the Potter" 3rd ed.
> Burleson's "Ceramic Glaze Handbook" 2nd ed.
> Bailey's "Glazes Cone 6"
> Cooper's "The Potters Book of Glaze Recipes"
> Robin Hopper's "The Ceramic Spectrum"
> and "Mastering Cone 6 Glazes".
>
I have four of these and a bunch of others. The thing about the books is that
they concentrate on one aspect or another to a greater or lesser extent. John
Britt's (The Complete Guide to High-Fire Glazes) book for example, has a great
deal on cone 10 firing for glazes that I've not seen elsewhere. While I don't
dispute that some work appears, and is, sloppy incomplete etc. etc. if one
takes the time one can gather the threads. I believe a truly
comprehensive work
on glazes would be very scary to confront :) But of course I'd buy it ! If you
want some interesting info from a book with an industrial bent try Richard
Eppler's and Mimi Obstler's Understanding Glazes. The treatment of colour is
very interesting.
As to photos ... well I'm not sure anymore what I think. A decent or half
decent description with notes on the body would suffice. Colour,
surface, gloss
and so on are such subtle things. But a photo does give an idea I
guess. The way
I'm looking at it now more and more, is that if I can pull the
principles out of
the books I have and the testing I do, I should be able to develop my
own glazes
for my own bodies and firing to achieve what I want. I am one hell of a
long way
from this, but ....
One thought just scurried across my mind. Hopper's book contains a ton of
information. It needs a little mining. Perhaps that's an interesting task.
Thanx
D
Alex Solla on fri 21 jul 06
Ivy-
All of the books you mention were written for potters. Like it or not, potters arent all scientists. If you want the fun stuff, read Cullen Parmelee's Ceramic Glazes. Mighty fun stuff. If you'd like, email me off list and I can give you a nice fat bibliography that will keep you ruminating for a long while.
cheers,
Alex Solla
Cold Springs Studio Pottery
4088 Cold Springs Road
Trumansburg, NY 14886
607-387-4042 voice/fax
www.coldspringsstudio.com
Ivy Glasgow wrote: --- In clayart@yahoogroups.com, Alisa Liskin Clausen wrote:
> Dear Ivy
> Unfortunately, choosing to work in ceramics does not entitle one to hard
> and fast, undisbutable knowledge.
>
> I am personally offended by the following comment as it is shafes my
> tolerance for bad behavior and arrogance. John Britt, John Hesseberth, Ian
> Currie, Ron Roy, Tom Buck, Hamer and Hamer, etc. are not witch doctors.
> You are eager to learn but also seem to want promised results in the form
> of written instructions.
Let me clarify my rant: I may not be working from the best books, and I
would certainly appreciate recommendations! I don't intend any slam on
authors who carefully document their work and present it in a sensible way.
My complaint is with the outright sloppiness of method & presentation that
I have observed in several of the books I'm working with. Things like
showing a picture of a glaze, with no formula. Or throwing out a bunch of
formulae without having tested them or photographed them. Or calling a
formula "food-safe" without test results or instructions as to limits
of the oxides that can be put into it. Showing a test tile of an
obviously unintentionally crawling or crazed glaze and calling it a
great glaze. If I am paying for a book that someone has taken the time
and effort to publish, I *do* expect better "written instructions" than
that, and I think everyone should!
That being said, I haven't read any of the authors you mention except for JH
and RR's MC6G. That's a mighty fine book, and my only problem with it is
that there's not enough of it. Hey guys, how about a volume 2, with a focus
on color development?
I am so far working with:
Rhodes' "Clay and Glazes for the Potter" 3rd ed.
Burleson's "Ceramic Glaze Handbook" 2nd ed.
Bailey's "Glazes Cone 6"
Cooper's "The Potters Book of Glaze Recipes"
Robin Hopper's "The Ceramic Spectrum"
and "Mastering Cone 6 Glazes".
Any suggestions for more enlightening resources would be greatly
appreciated. Even at $40 a pop, if it saves a couple hours of
hair-tearing, it's more than worth it.
-Ivy G.
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Hank Murrow on fri 21 jul 06
On Jul 21, 2006, at 10:16 AM, Ivy Glasgow wrote:
>
> Any suggestions for more enlightening resources would be greatly
> appreciated. Even at $40 a pop, if it saves a couple hours of
> hair-tearing, it's more than worth it.
OK Ivy;
I strongly recommend Ian Currie's "Revealing Glazes", and "Stoneware
Glazes", available from his website(takes a week) at
http://ian.currie.to/
Where Steve Harrison's books are also available, BTW.
"Revealing Glazes" is the most comprehensive book of theory and
practice that I have used. His method works at any temperature, and
whether or not you have a analysis of all your materials. Several of my
glazes are published in the book as examples of 'extremes' to get
certain colors. I receive no royalties from Ian.... just his good
company whenever he is near Oregon.
I think you will be surprised if you try it.
Cheers, Hank
www.murrow.biz/hank
Fred Parker on sat 22 jul 06
Dear John (and Ivy):
Couldn't have said it better myself!...
One of my fondest memories from college is the time I took a course
called "pilot plant operations." It's a course in which students produce
some chemical product in the lab (milliliters and grams), then scale it up
much larger and try to get the same results in a "pilot plant," or
miniature production plant where you're working with gallons and pounds.
I'm sure you (John) had a similar experience.
It was a long time ago, and I cannot recall the product we sought, but I
do remember it was to have been a snow white crystaline substance we would
precipitate out of an aqueous solution. That is exactly what we got in
the lab. It took us about 3 hours total.
Next we moved into the pilot plant. We were about as cocky as anyone
could get, having heard all the horror stories from those who took the
course before. However, our lab yields were great, and our product
quality was exceptional. How hard could it be to just do the same thing
at a larger scale?! We got underway around 2:00 PM, looking forward to
the celebratory beer and pizza we'd have around 6:00 PM after the lab.
Didn't work out that way...
Around 3:30 AM I had my head stuffed into a centrifuge the size of an
overgrown commercial washing machine, trying to scrape off something that
looked pretty much like molasses with tar mixed in. Somebody else on our
team was trying every solvent he could get his hands on desperately
searching for something that would dissolve a mysterious, unidentifiable
residue in the reactor. Together, we had all resigned ourselves to failing
the course. No question about it -- we would have to take it again, and
they only offered it once per year. That meant some of us would have to
delay graduation. Somebody finally said, "just to hell with it" and left
to go buy beer, which we ended up finishing just about the time the
professors started arriving for a new day. It was like knowing the end of
the world had happened, and we somehow lived through it all. There was
nothing to look forward to anymore, and much to mourn.
It was only later that I realized the point of "pilot plant operations"
was to make us understand what you just explained. Product was not as
important to the professor as snatching us into the "real world" where
samples are not as pure as what the graduate student in the quant lab
handed out for us to analyze. Raw materials, in spite of batch numbers
and analysis results, do not always hold true to expectations. Nowhere I
have seen is this more true than in glazing, where almost nothing is known
in absolutes. This is exactly why I use the term, "voodoo" so often when
discussing it.
It is also a big reason I believe glaze formulas need much more content
than ingredients and percentages. With almost everything unknown,
recording what little IS known cannot possibly hurt!
Ivy, chemistry might be chemistry the world around. But if I don't have a
clue what's entering into the reaction, I really don't have a clue what's
coming out.
But keep on keeping on...
Fred Parker
On Fri, 21 Jul 2006 07:20:16 -0400, John Hesselberth
wrote:
>On Jul 20, 2006, at 3:12 PM, Ivy Glasgow wrote:
>
>> I think that there's very little "mystery" in glaze
>> colors that could not be solved with some careful experimentation and
>> documentation. Transportability be darned, chemistry is still
>> chemistry, the
>> world around. I also think that the artists who write these books
>> seem to
>> have very little concept of scientific method, and treat chemistry
>> like
>> voodoo. I also think that there's no point in twisting a formula so
>> far out
>> of stability that it will yield a copper yellow- isn't that what iron,
>> rutile, and yellow stains are for?? Why can't I have one base glaze
>> for all
>> colors and all seasons??
>
>Hi Ivy,
>
>First be my/our guest at being the person to sort all this out and
>turn it into hard reproducible science. Lots of very smart people
>have spent decades of their lives over the last century or two trying
>to do just this and weren't able to complete the job. It wasn't for
>lack of trying or for lack of understanding and using the scientific
>method. But hopefully you will succeed.
>
>What I think you are missing is the complexity of the system. For
>example we are not dealing with simple chemistry. It is extremely
>complex chemistry. But even worse it is not 'just chemisty'-- is a
>combination of chemistry and physics. Color depends on the
>reflectance and transmittance of light and that in turn depends not
>just on chemistry but crystal forms, crystal sizes, thickness of the
>light path, and probably several more things I have skipped over.
>Then there is the impurity of our raw materials. We are not dealing
>with simple college chemistry lab systems. And of course there are
>other variables in the system that are not totally controllable
>without using systems so expensive we could not afford them.
>
>Those of us who have a scientific or engineering background usually
>enjoy sorting through all these variables and learning bits and
>pieces about how they work together (or not). But if your frustration
>level gets too high I would suggest switching to using stains--they
>are a bit more predictable (though also more 'uninteresting' in my
>opinion). They are manufactured materials where quality and
>consistency has been controlled to a significant degree. And they
>have been put into a form where they interact less with the glaze
>'soup'. In a simplified way they are just particles of color
>suspended in the glass. Or if your frustration gets really high maybe
>you should taking up oil painting. There you can mix blue and yellow
>and get green. Sorry, you can't do it with glazes.
>
>In the meantime good luck on your quest. We will enjoy hearing of
>your progress.
>
>Regards,
>
>John
>
>__________________________________________________________________________
____
>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.
Ivor and Olive Lewis on sun 23 jul 06
Dear Fred Parker,=20
To get to the Utopian ideals you wish for would require the services of =
high level analytical laboratory and the ability to refine raw =
ingredients down to better than five nines purity. Based on your reports =
you seem to profess having learned the skills and knowledge to do that, =
so you should be able to get to the basis you aspire to for very little =
expense..
I prefer to accept those quirks of nature blessed on my work by =
impurities in my raw materials.
Best regards,
Ivor=20
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