Alisa Liskin Clausen on sun 31 dec 06
glaze that crazes.
On Sun, 31 Dec 2006 01:40:46 -0000, claystevslat
>The principal reason for the lessening of crazing with colorants
>is the difference in COE between our colorants and the other
>elements in a glaze. I thought I had identified a characteristic
>with copper involving crazing, but my impression was that glazes
>with copper crazed over fewer clays (i.e., fitted well over a
>broader range of clay) than the same glaze without. It may be that I
>was wrong, and didn't retest over sufficient numbers of bodies
>after adding copper ...
>
Hi Steve
In priniciple, I would say that your findings with Copper make more sense
than mine, however, I have seen crazing with the additon of Copper to an
otherwise uncrazed base. I know it has to do the with expansion, as you
say with the colorant oxides and the glaze materials, but I would like to
make tests where I could see a pattern, as for now, my results are very
random.
Let us see if someone else has insights on this and I could get a place to
start.
Best regards from Alisa in Denmark
claystevslat on sun 31 dec 06
glaze that crazes.
Alisa --
I sometimes do a second check with liquid ink -- put a few
drops inside a test bowl and let it sit for a day, then wash
it out. It reveals hidden crazing sometimes (naturally a
sufficiently dark glaze and black ink combination just
doesn't do anything).
The principal reason for the lessening of crazing with colorants
is the difference in COE between our colorants and the other
elements in a glaze. I thought I had identified a characteristic
with copper involving crazing, but my impression was that glazes
with copper crazed over fewer clays (i.e., fitted well over a
broader range of clay) than the same glaze without. It may be that I
was wrong, and didn't retest over sufficient numbers of bodies
after adding copper ...
It'd be interesting to pursue this point, though.
Steve S.
--- In clayart@yahoogroups.com, Alisa Liskin Clausen wrote:
>
> Dear Clayart,
>
> Over time I have noticed a pattern when I test clear bases with
coloring
> oxides.
>
>
>
> Base glazes that craze on my clay body, can appear with no crazing
when
> coloring oxides are added.
Alisa Liskin Clausen on sun 31 dec 06
glaze that crazes.
>Hi Alisa,
>I too have been puzzled by the fact that not much has been said on
>opacifiers and colouring oxides affecting expansion rates. When I do =
the
>glaze calculation programs and include these in the totals, there can =
be
>significant differences.
>According to Glazemaster and using Shaner's Clear it has an exp =
coefficient
>of 67.60.
>5% additions of tin, chromiun oxide, cobalt carbonate, copper =
carbonate,
>nickel carabonate all lower it by 3.63, zircopax lowers it by 2.97 and
>manganese carbonate by 1.09.
>Red iron oxide raises it by 3.09, Ilmenite by 3.62 and titanium by =
4.11.
>I always felt that adding Fe resulted in less crazing, same with Cu - =
but
>that could be because the glaze melted more and so more interaction =
between
>the body and glaze?
>It is strange that Sn, Co, Cu, Ni all lowered it by the same amount - =
maybe
>just an arbitrary figure was used for these. But Mn, Fe, Ilmenite and =
Ti
are
>all found in other glaze ingredients so a proper individual value had =
to be
>used. Have to check with John Hesselberth on that. I guess how much the
>expansion rate has to change depends on how far apart glaze and clay =
body
>are and if oxide addition is affecting the melt?
>Will try to look more closely as doing lots of glaze experiments as we =
have
>just gotten a gas kiln. >=20
=20
Dear Eve,
This is the type of information I am trying to collect. We know that =
some
colorants will flux a glaze and therefore give more melt, more =
interaction
with the clay body.
=20
The expansion rates for many oxides are listed in MC6G on page 76. I =
think
what has me wondering about the calculation of COE of a glaze, is that =
the
recipes are calculated excluding the addition of the coloring oxides.
However, they do have an effect on the overall COE of a glaze. If =
between
1-4 in decrease or increase is worthy of taking notice of, I do not =
know.
But in the tests, they appear to be capable of making the difference =
between
crazed or not. So, I am back to why are the coloring oxides not =
included in
the unity calculation? I do not know, and my questions are prompted =
only
by observing my tests over a longer period of time. I am positive the =
glaze
scientists have check on this and now I have become curious because of a
pattern I have observed.
The other hunch I have, is this a vast area of information to be culled =
and
it is not as easy as a few chapters. I know that sometimes there are =
topics
I am so na=EFve about, that if I knew a little about them, I would =
realize how
little I know. But nonetheless, this has sparked my interest.
=20
However, as said, I have not tested the colored tiles for crazing. I =
can
make the tests in Chapter 3 of MC6G, from freezer to boiling water, and =
wait
and see. That will also give me a better insight to the degree of aid =
in
stopping crazing, a coloring oxides gives (or not).
=20
Thanks a lot for your information. I hope others will have insights and
experiences to share on this topic.
=20
Happy New Year
Regards from Alisa in Denmark
Nancy on mon 1 jan 07
glaze that crazes.
Alisa
I tried the 5/20 recipe for clear glaze . When clear it crazed
horribly...like nothing I've seen before. I then decided to add some
cobalt since I was looking for a nice blue...when I fire it's strange
the results I get. Fire at cone 5-6, it is a matt blue that is very
nice and doesn't craze at all. Fire it at cone 7 it is opaque and shiny
blue. No crazing again. Now...if I fire that same transparent 5/20 w/o
colorants on Laguna's Miller 50 clay body I get no crazing but on Laguna
66, B mix, Bmix with grog, standard 181...all crazes with just the clear
but when colorant is added....no crazing.
I also tried this with Laguna's Jon's Transparent which did not craze
but bubbled and crawled. I added the same cobalt oxide to it and the
same, it got rid of the crawling and bubbles.
I'm not a glaze guru in any way....not a chemist either so I don't have
a clue why these glazes do this but thought I'd share anyway.
Nancy
www.hilltoppottery.com
Alisa Liskin Clausen wrote:
> Dear Clayart,
>
> Over time I have noticed a pattern when I test clear bases with coloring
> oxides.
>
>
>
> Base glazes that craze on my clay body, can appear with no crazing when
> coloring oxides are added.
>
> In most cases, percents of 5-10 RIO or 1-2 Cobalt will show un crazed. I
> have not studied these surfaces under
>
> a microscope, but they are clearly improved surfaces when looking at them in
> sunlight. An example of this is the last colorant tests I made,
>
> using Brian Gartside's Volume Clear Glaze. The clear was badly crazed, but
> all the tiles, colored with RIO and Cobalt, were not crazed.
>
> However, since the base was crazed, I feel nervous about the seemingly un
> crazed tiles. I mean, maybe they are crazed, but I do not see it.
>
> Or, like shivering can much later, perhaps crazing can also happen much
> later.
>
>
>
> I have used this base now in a bigger batch with 10 RIO, and the pots are
> not crazed, as I can see. In fact, the glaze is looks like a lush Tenmoku
>
> at Cone 6.
>
>
>
> Contrary to this improvement, I have seen Copper Oxide as a colorant, make
> an un crazed clear glaze,
>
> craze.
>
>
>
> I would like to study this closer. Is there any documentation on the above?
> Suggestions for glaze testing to
>
> further investigate this? Do coloring oxides have an effect on expansion of
> a glaze? Maybe a big yes, and this is an
>
> area I in the dark about, or, it could be something interesting to study.
>
>
>
> After the weekend, I am starting up again and would like to look into this
> relationship, if there is one.
>
>
>
> These evenings I have reread all of the articles I thought where interesting
> in my year of Clay Times and Pottery Illustrated.
>
> I think the columns in Clay Times have excellent information that one can
> benefit from reading a few times.
>
>
>
> Best regards from Alisa in Denmark
>
> Cloudy, stormy New Year's Eve predicted,
>
> so not so good for seeing fireworks. Tradition calls
>
> for the Queen's New Year's address, a dinner of codfish and mustard sauce,
>
> and literally jumping into the New Year, from little stools or chairs,
> depending on one's
>
> bravery.
>
> ______________________________________________________________________________
> 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.
>
>
Eva Gallagher on mon 1 jan 07
glaze that crazes.
Hi Alisa,
I too have been puzzled by the fact that not much has been said on
opacifiers and colouring oxides affecting expansion rates. When I do the
glaze calculation programs and include these in the totals, there can be
significant differences.
According to Glazemaster and using Shaner's Clear it has an exp coefficient
of 67.60.
5% additions of tin, chromiun oxide, cobalt carbonate, copper carbonate,
nickel carabonate all lower it by 3.63, zircopax lowers it by 2.97 and
manganese carbonate by 1.09.
Red iron oxide raises it by 3.09, Ilmenite by 3.62 and titanium by 4.11.
I always felt that adding Fe resulted in less crazing, same with Cu - but
that could be because the glaze melted more and so more interaction between
the body and glaze?
It is strange that Sn, Co, Cu, Ni all lowered it by the same amount - maybe
just an arbitrary figure was used for these. But Mn, Fe, Ilmenite and Ti are
all found in other glaze ingredients so a proper individual value had to be
used. Have to check with John Hesselberth on that. I guess how much the
expansion rate has to change depends on how far apart glaze and clay body
are and if oxide addition is affecting the melt?
Will try to look more closely as doing lots of glaze eperiments as we have
just gotten a gas kiln. So far just about every recipe (25) has resulted in
crazing on every clay body (5) we have tested!
Regards,
Eva Gallagher
Deep River Potters' Guild
----- Original Message -----
From: "Alisa Liskin Clausen"
To:
Sent: Sunday, December 31, 2006 4:19 AM
Subject: Re: Coloring oxides and their affect on stopping crazing in a base
glaze that crazes.
> On Sun, 31 Dec 2006 01:40:46 -0000, claystevslat
>>The principal reason for the lessening of crazing with colorants
>>is the difference in COE between our colorants and the other
>>elements in a glaze. I thought I had identified a characteristic
>>with copper involving crazing, but my impression was that glazes
>>with copper crazed over fewer clays (i.e., fitted well over a
>>broader range of clay) than the same glaze without. It may be that I
>>was wrong, and didn't retest over sufficient numbers of bodies
>>after adding copper ...
>>
>
>
> Hi Steve
> In priniciple, I would say that your findings with Copper make more sense
> than mine, however, I have seen crazing with the additon of Copper to an
> otherwise uncrazed base. I know it has to do the with expansion, as you
> say with the colorant oxides and the glaze materials, but I would like to
> make tests where I could see a pattern, as for now, my results are very
> random.
>
> Let us see if someone else has insights on this and I could get a place to
> start.
>
> Best regards from Alisa in Denmark
>
> ______________________________________________________________________________
> 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.
>
John Hesselberth on mon 1 jan 07
glaze that crazes.
On Dec 30, 2006, at 3:39 PM, Alisa Liskin Clausen wrote:
> I would like to study this closer. Is there any documentation on the
> above? Suggestions for glaze testing to further investigate this? Do
> coloring oxides have an effect on expansion of a glaze? Maybe a
> big yes,
> and this is an area I in the dark about, or, it could be something
> interesting to study.
Hi Alisa,
I'm not aware of much in the literature studying the effect of
colorants on crazing and/or shivering. I think it is an excellent
area to explore because they clearly do have an effect. We do have an
expansion coefficient for iron oxide so, for example, if you enter it
as an ingredient in a program like GlazeMaster it will be included in
the calculation. If you enter it as an additive it will not be
included in the calculation. It has quite a high expansion
coefficient so will make a big difference in the glaze when it is
used at high levels.
That, by the way, is why we get away with a glaze like Waxwing Brown
in MC6Gs. If you calculate the expansion of that glaze without the
iron you would worry that it might shiver. But with the iron added in
it comes into a normal range. So that is the primary reason we call
that glaze a specialty glaze and don't recommend it as a general
purpose base glaze. It needs lots of iron oxide to be in the non-
shivering range of COE.
If I were going to explore this (and I didn't have access to a
dilatometer--which most of us don't) I would start as follows: I
would take a set of base glazes that have varying expansion
coefficients like the set in Chapter 5 of MC6Gs. I would mix them and
put them on a porcelain and a stoneware body. Then I would add a
significant amount of several colorants to each of those glazes--one
at a time--say 5% copper carbonate, 10% iron oxide, 2% cobalt
carbonate--amounts that are near the maximum of what we normally use.
I think, after firing and examining, those tiles or pots you could
develop a pretty good idea of how each colorant is affecting the
expansion of the glaze. If it were done thoroughly enough you could
even begin to roughly back calculate expansion coefficients because
you would know how far a given colorant moved the expansion
coefficient of the glaze from the shift in crazing point in the 5
glazes set.
Regards,
John
John Hesselberth on mon 1 jan 07
glaze that crazes.
On Dec 30, 2006, at 3:39 PM, Alisa Liskin Clausen wrote:
> I would like to study this closer. Is there any documentation on the
> above? Suggestions for glaze testing to further investigate this? Do
> coloring oxides have an effect on expansion of a glaze? Maybe a
> big yes,
> and this is an area I in the dark about, or, it could be something
> interesting to study.
Hi Alisa,
A couple additional thoughts. You may find that at "low" levels a
colorant affects the COE one way, while at "high" levels it affects
it another. For example if the colorant is completely soluble in the
melt it may have a different effective expansion coefficient than if
you have exceeded the solubility limit and some of it is dispersed
rather than dissolved in the glass phase. That could explain an
effect like you are seeing where iron oxide seems to lower the glaze
expansion where I have said in Waxwing it is necessary to raise the
expansion.
There is lots of room to explore it and it will take a careful
experimenter like you are to sort it all out.
John
Alisa Liskin Clausen on tue 2 jan 07
glaze that crazes.
If I were going to explore this (and I didn't have access to a
dilatometer--which most of us don't) I would start as follows: I
would take a set of base glazes that have varying expansion
coefficients like the set in Chapter 5 of MC6Gs. I would mix them and
put them on a porcelain and a stoneware body. Then I would add a
significant amount of several colorants to each of those glazes--one
at a time--say 5% copper carbonate, 10% iron oxide, 2% cobalt
carbonate--amounts that are near the maximum of what we normally use.
I think, after firing and examining, those tiles or pots you could
develop a pretty good idea of how each colorant is affecting the
expansion of the glaze. If it were done thoroughly enough you could
even begin to roughly back calculate expansion coefficients because
you would know how far a given colorant moved the expansion
coefficient of the glaze from the shift in crazing point in the 5
glazes set.
Regards,
John
Hi John,
This is the direction I am looking for and needed. Sometimes doing a lot
of tests and studying them will reveal a lot of information. The trick
for me is, how to categorize the information and do something constructive
with the questions raised. With so many variables, it always important for
me to keep a few common denominators. That will the glaze bases, plus I
will add Brian Gartsides base, as it crazed on my normal throwing body. I
have tested 20 x 20 for color responses, but that will not be included, as
it has never crazed for me. I must look over all of my clears that have
crazed, and there are many. That is one of reasons I have so few up on my
website.
I am interested in this pursuit and will get my tests lined up. I know
that Ron has a dilatometer and is always very generous. However, I am not
so interested in my particular glazes, but would like to see a general
response and detect a pattern. Your idea is quite good and gives me some
perameters to work within. When I get this set up and fired, I will post
the results./
I must order a new GlazeMaster. For some reason the copy I have does not
want to be downloaded on my computer. I know that the colorants can be
added to the glazes, however, in general we treat them as Additions. This
can be misleading to the outcome of the glaze's COE.
I am very excited, again, again!
Thanks to all for your feedback,
Best regards from Alisa in Denmark
Making NCECA plans...expensive, but I think I will.
claystevslat on tue 2 jan 07
glaze that crazes.
Nancy -- cobalt as a colorant changes the COE of the glaze somewhat,
but the important thing about it is that it's a powerful flux --
adding cobalt to the glaze will integrate more of the clay body into
the final glaze.
(The following is is terribly oversimplified, and will offend the
chemists among us.) A glaze that fluxes better will incorporate more
material from the clay body itself into the glaze. Good fit between
clay and glaze is going to be easier to attain with a glaze that
picks up more of the material of the clay,as it's COE will tend more
towards that of the underlying clay.
The specifics of your blue glaze experience are a bit murky to me --
often a glaze that's matte at a lower temp and glossy a cone higher
is simply underfired at the lower temp. It may be within its 'safe'
range, though. Only testing can show that, though.
As far as the two clays giving different results, I'm sure you
already know that clays have different COE's. I don't believe most
manufacturers provide much information about this, though (they're
not always good about providing info about wet-to-fired shrinkage,
either) so what you have done is to find one clay for which 5 x 20
is a good fit. If we knew what the COE was of our clays, we'd be 90
percent of the way to finding well-fitting clays for that and
similar glazes, and identifying glazes before mixing them up that
might perform well over that group of clays ...
Best wishes -- Steve Slatin
--- In clayart@yahoogroups.com, Nancy wrote:
>
> Alisa
>
> I tried the 5/20 recipe for clear glaze . When clear it crazed
> horribly...like nothing I've seen before. I then decided to add
some
> cobalt since I was looking for a nice blue...when I fire it's
strange
> the results I get. Fire at cone 5-6, it is a matt blue that is
very
> nice and doesn't craze at all. Fire it at cone 7 it is opaque and
shiny
> blue. No crazing again. Now...if I fire that same transparent
5/20 w/o
> colorants on Laguna's Miller 50 clay body I get no crazing but on
Laguna
> 66, B mix, Bmix with grog, standard 181...all crazes with just the
clear
> but when colorant is added....no crazing.
>
> I also tried this with Laguna's Jon's Transparent which did not
craze
> but bubbled and crawled. I added the same cobalt oxide to it and
the
> same, it got rid of the crawling and bubbles.
>
> I'm not a glaze guru in any way....not a chemist either so I don't
have
> a clue why these glazes do this but thought I'd share anyway.
>
> Nancy
> www.hilltoppottery.com
Alisa Liskin Clausen on wed 3 jan 07
glaze that crazes.
>John H made some good suggestions, but I think it is a
>bit ambitious. Although I am sure you can handle it.
>His method involve glazes in various PH and Si:Al
>ratio. I would be nervous if I have to vary too much
>of those too soon as we know PH and Si:Al (Are they
>the same thing?) affect how colouring oxides behave.
>Perhaps that is exactly the point. I found small steps
>and simple objective set up a comfortable base camp
>for a long glaze trail. How about just change one
>variable at a time? Like varying the percentage of the
>colouring oxide and get yourself some serious
>equipments that go beyond 20/20 to see the effect of
>the oxides on stopping crazing in a crazed base glaze?
>The result might gives suggestions to further testing
>ideas.
>
Hi Mary,
I am not sure what you mean by quote the ceramist's COE?
In the past I have made a lot of tests and try to pay close attention to
them. Thus I begin to see this pattern with crazed bases and oxides
helping to stop crazing.
The idea is to use several bases that craze, and add coloring oxides in
varing procents. John has suggested the bases in his book as they have
different expansions. My idea is very plain.
Glaze 1
Glaze 2
Glaze 3
100 grams each
add one coloring oxide in increasing percents,
say 1,2, 3, 5 8, 10% and then oversaturate with 15%
I have 6 portions of Glaze 1 with Cobalt
6 portions with Copper,
6 portions with Iron
now I have 18 tests for Glaze One
Same for Glaze 2
Same for Glaze 3
I have 54 tests.
Then do the same with Zircopax, an irregular verb of an oxide at cone 6.
Now I have 60 tests.
I think they will tell a lot. I will use a lens to inspect them and I will
freeze and boil them.
This is how I learn and this is my plan for now. Reading is absolutly
essential and as important for me, is the doing and studying of glaze
tests. I am not sure how ambitious this is, it seems very logical. I
just hope the tests will tell me something. If not, then try again
something else, or if not enough, work further. The glazes have a lot of
variables, all those materials. The constant will be the increase of
oxides in the blends.
Good luck with your testing in the US.
Best regards, Alisa in Denmark
May Luk on wed 3 jan 07
glaze that crazes.
Hi Alisa;
I don't know what you mean by Mary. Why you turn my
name into a four letter word? No matter. I really gave
your quest some serious thoughts and I spent some time
re-reading the threads before I wrote my post. It
takes me a long time writing anything. I sincerely
thought you want to extrapolate your data rather than
merely collecting them. Apology for the intrusion.
Be seeing you
May
Glaze 1: What is your COE?
Glaze 2: I'm not a number. I am a free glaze!
Alisa Liskin Clausen on thu 4 jan 07
that crazes, May Luk
On Wed, 3 Jan 2007 22:37:10 +0000, May Luk wrote:
>Hi Alisa;
>
>I don't know what you mean by Mary. Why you turn my
>name into a four letter word? No matter. I really gave
>your quest some serious thoughts and I spent some time
>re-reading the threads before I wrote my post. It
>takes me a long time writing anything. I sincerely
>thought you want to extrapolate your data rather than
>merely collecting them. Apology for the intrusion.
>>Be seeing you
>May
>
>Glaze 1: What is your COE?
>Glaze 2: I'm not a number. I am a free glaze!
in response to my post:
>Hi Mary,
I am not sure what you mean by quote the ceramist's COE?
In the past I have made a lot of tests and try to pay close attention to
them. Thus I begin to see this pattern with crazed bases and oxides helping
to stop crazing.
The idea is to use several bases that craze, and add coloring oxides in
varying percents. John has suggested the bases in his book as they have
different expansions. My idea is very plain.
Glaze 1
Glaze 2
Glaze 3
100 grams each
add one coloring oxide in increasing percents, say 1,2, 3, 5 8, 10% and then
oversaturated with 15%
I have 6 portions of Glaze 1 with Cobalt
6 portions with Copper,
6 portions with Iron
now I have 18 tests for Glaze One
Same for Glaze 2
Same for Glaze 3
I have 54 tests.
Then do the same with Zircopax, an irregular verb of an oxide at cone 6.
Now I have 60 tests.
I think they will tell a lot. I will use a lens to inspect them and I will
freeze and boil them.
This is how I learn and this is my plan for now. Reading is absolutly
essential and as important for me, is the doing and studying of glaze
tests. I am not sure how ambitious this is, it seems very logical. I
just hope the tests will tell me something. If not, then try again
something else, or if not enough, work further. The glazes have a lot of
variables, all those materials. The constant will be the increase of
oxides in the blends.
Good luck with your testing in the US.
Best regards, Alisa in Denmark
Dear May,
I am admittedly totally dumbfounded by your anger and sarcasm. In fact, I
read Mary a four letter word, it and said this is just nuts.
I really hope this is a both classic and horrid example of misinterpreting
the written word.
My first question was just a question, I did not understand what you meant
and was asking for a clarification to help me understand.
.
I made a simple mistake of misspelling your name. The glazes are numbered
just to simply represent 3 different glazes from MC6G.
The rest is how I will approach my tests, with suggestions by John H.
Anyone appreciates another person reading one's post and making
suggestions. That is one of the reasons I join this list. Yours are not an
exception. In fact, I read your posts because I like to hear what you are
doing. A lot of praising is not my M.O., however I am a big fan of quite
and subtle positive reinforcement.
Your response and anger has knocked me backwards, as my understanding from
your written words that they are sarcastic, belittling and angry.
All unnecessary because there is no reason to put me down. My post is most
neutral, with one question, one spelling error of your name and otherwise
just an outline of how I will approach my testing.
Odd to me, that by not abandoning my testing intentions in favor of yours,
you seem insulted that I do not give consideration or validate your
suggestions .
You write sarcastically about an intrusion. I would ask you to not feel
angry, as there is just no cause, as far I know, regarding these posts.
All is considered, but in the end, we work the way we work as individuals.
We are not usually deemed ungracious for doing that.
I am admittedly, very surprised by this reaction, if of course, I have
interpreted your post's emotions accurately. I write very carefully, as I
am used to expressing my self in a language other than my mother tongue, and
I in the habit of writing without making editorials or emotional
embellishment.
Glaze testing for me is not particularly emotional. I am however glad when
we on the list, have an open, helpful and rewarding dialogue.
Regards from Alisa in Denmark
May Luk on sat 6 jan 07
that crazes, Alisa
Hello Alisa;
Thank you for writing. First thing first, I never can
hold any grudges, so, no hard feelings. Another
classic case of mis-communcation and the effect of the
full moon. It was really full moon if you believe that
sort of things. I am not an angry person (so I think).
Impatience and aggressive, probably, but that is to do
with urban living.
Neither my ideas nor my goofiness came through. What a
disaster! My 'Prisoner' classic British TV glaze
number joke was bad timing. You and I have been
talking glaze for years and I have certain
friendliness towards you. I do have a thing with
misspelling though and this is to do with living in
England for a few years. Getting the name wrong is
never very nice. I was indeed a bit cross about that.
You had not said anything in the past with bad
intentions and I appreciate that. Let's not dwell on
what I said, what you said and my lousy communication
skill. Let's move on forward.
As we were, I was under the impression that you would
do calculations because you mentioned Glazemaster.
Crazing is about Coefficient of Expansion. We had this
long discussion about quoting COE values and the
ceramists a while back. That's why I bought it up. If
you are not doing calculations, the point is moot. If
you are going to do calculations and compare numbers,
then I would have a few points to bring forward for
the brain storming session. And I would offer to plot
graphs for you. This would mainly be for my own
learning.
Please forgive me if this is out of left field and I
sincerely not meant to be sarcastic. I cannot wrap my
head around testing oxide over 5%. Surely it's
essential to look at all possible scenarios. We are
both from the school of Mastering Cone 6, 5% plus
colouring oxide means the glaze is likely not stable.
If it's not stable, it doesn't matter if it is crazed
or not. Crazed glaze is not a fault as long as it's
not on functional tableware. Not to say there is no
application for the 5% plus oxide test, I just don't
see it being very useful yet.
I hope your first round of testing will bring in much
insight.
Until next time
May
Kings County
Alisa Liskin Clausen on sat 6 jan 07
that crazes, Alisa
Sat, 6 Jan 2007 05:21:04 +0000, May Luk wrote:
>Hello Alisa;
>
>Thank you for writing. First thing first, I never can
>hold any grudges, so, no hard feelings. Another
>classic case of mis-communcation and the effect of the
>full moon. It was really full moon if you believe that
>sort of things. I am not an angry person (so I think).
>Impatience and aggressive, probably, but that is to do
>with urban living.
>
>Neither my ideas nor my goofiness came through. What a
>disaster! My 'Prisoner' classic British TV glaze
>number joke was bad timing. You and I have been
>talking glaze for years and I have certain
>friendliness towards you. I do have a thing with
>misspelling though and this is to do with living in
>England for a few years. Getting the name wrong is
>never very nice. I was indeed a bit cross about that.
>
>You had not said anything in the past with bad
>intentions and I appreciate that. Let's not dwell on
>what I said, what you said and my lousy communication
>skill. Let's move on forward.
>
>As we were, I was under the impression that you would
>do calculations because you mentioned Glazemaster.
>Crazing is about Coefficient of Expansion. We had this
>long discussion about quoting COE values and the
>ceramists a while back. That's why I bought it up. If
>you are not doing calculations, the point is moot. If
>you are going to do calculations and compare numbers,
>then I would have a few points to bring forward for
>the brain storming session. And I would offer to plot
>graphs for you. This would mainly be for my own
>learning.
>
>Please forgive me if this is out of left field and I
>sincerely not meant to be sarcastic. I cannot wrap my
>head around testing oxide over 5%. Surely it's
>essential to look at all possible scenarios. We are
>both from the school of Mastering Cone 6, 5% plus
>colouring oxide means the glaze is likely not stable.
>If it's not stable, it doesn't matter if it is crazed
>or not. Crazed glaze is not a fault as long as it's
>not on functional tableware. Not to say there is no
>application for the 5% plus oxide test, I just don't
>see it being very useful yet.
>
>I hope your first round of testing will bring in much
>insight.
>
>Until next time
>May
>Kings County
>
Dear May,
All is good, all is fine, am for that I am glad.
Writing can be disastrous. I think you hit the nail on the head to say
that we have talked glaze for so long, and perhaps it was therefore I was
thrown for a loop. Your insights and information are helpful and
thorough. For all my careful testing, my writing and everyday can
sometimes be like a small explosion - my thoughts 10 meters up, waiting
for my fingers and good sense filter to reach. So I can be guilty of
misspellings and typos. My name is changed all the time from Alisa (A LEE
SA to Alexa, Alice, Lise, Alissa, , Felicia, you name it. I worked with 40
different nationalities on board, and for whatever we did not know how to
say, it became a ching a ling. But honestly, Danes usually call me
Aleeza) So, May, Good, so now we can continue the discussion.
My urban living days are found when I visit New Jersey. I live in between
a cow field and a fjord and stress is deciding if I should winter bathe
before or after I make my bed. Then of course, there is the studio stress=85=
I need 16 mugs and I only threw 9.
Yes, absolutely will I calculate the glazes. John and Steve have been
helping me to get my Glaze Master up and running again. I had the version
1.0 and it did not want to load onto my new computer. Now John and Steve
have worked with me, and as usual, generosity in our community makes
things happen.
I plan to calculate the glazes.
As far as stable, that is another sector. Yes, I understand you not seeing
any purpose in any increments above 5%, because the glaze would not be
stable and not useful for functional pottery, according to MC6G limits.
However, I am interested in the first phase, to see how much of an oxide
will get the glaze to stop crazing (how much the COE is changed). It will
be interesting to see what percents lower expansion and perhaps, at what
level the oxides begin to go in the other direction, if that will happen.
For now, I am not looking for stable glazes, I am looking at percents of
oxides and their influence of a base glaze=92s expansion. Maybe the second
round of testing will be to separate the bases with oxides under 5% and
see how many are stable. From that =93palette=94 perhaps we can chose a few=
glazes to work with, get them into limitations and use them. But, I am
not looking for functional glazes, I am looking at rates of expansion.
This is a big bite to chew for me, because I am only as good as what I
read and test. I was quite pleased with my stain fuming tests, but I
rarely embark on something as scientific as this, because, well, I lack
the experience. This is a way to get it. So, let=92s just sit back and
enjoy the ride!
I am using MC6G base glazes as models for these experiments. John has
suggested the 5 glazes listed in Chapter 5, and I think that is a good
idea. I have a lot of crazed transparent glazes, but these will give me
some much needed parameters as a starting point. Furthermore, John has
suggested that I use a stoneware and a porcelain. I will do that and make
absorption tests on the two bodies. Tom Buck has given me some good
coaching as well, and I sure this will become an excellent colaboration.
So, that is where I am at. When I get something done and have
calculations, I will thank you for graphing the info. Any ideas are
welcome.
Best regards from Alisa in Denmark
sacredclay on sun 7 jan 07
that crazes, Alisa
This was a helluva interesting read, namely because I've realized by
now that it's incredibly interesting to misread the intentions behind
the wordsand like some, have even bristled (and loudly,too) at some
of the responses that were meant to educate, not deride me. On the
side note, I apologize to Dolita for reacting like that.)But I
digress, as usual.My question springs from the Glazemaster
claculations. I've never used that, or any other programs that deals
with that simply because I'm not that knowledgable about computers,
but also numbers frighterns me becasue I can't get my head around
them at times.I know formulas should equal about 100.00. I know that
more than 5% of Bentonite isn't good. I now know that more than 5%
copper isn't that safe.Repetition will help. What I want to know is
that if the Glazemaster calculates a recipe,will it also tells me
that it's either correct or incorrect? Will it also tells me what I
need to do to correct a problem? does it just list recipes? What else
can it do? the silica Alumian ratio doesn't tell me anything. At what
level should it be in? I'd like to hear from other's experience as to
what they've found helpful and frusterating with the program. Its'
not enough to tell me that it's great. All things are advertised
as "they'rrrr grrrrreat!". Much thanks to all. Kathryn in NC > >with
urban living.
> >
> >Neither my ideas nor my goofiness came through. What a
were, I was under the impression that you would
> >do calculations because you mentioned Glazemaster.
> >Crazing is about Coefficient of Expansion. We had this
> >long discussion about quoting COE values and the
> >ceramists a while back. That's why I bought it up. If
> >you are not doing calculations, the point is moot. If
> >you are going to do calculations and compare numbers,
>
> Yes, absolutely will I calculate the glazes. John and Steve have
been
> helping me to get my Glaze Master up and running again. I had the
version
> 1.0 and it did not want to load onto my new computer. Now John and
Steve
> have worked with me, and as usual, generosity in our community makes
> things happen.
> I plan to calculate the glazes.
>
>
Jonathan Kirkendall on mon 8 jan 07
that crazes, Alisa
Kathryn,
When I got my first glaze program, I knew some about glazes, but not a
whole heckuva lot. I found that learning about the software and how it
worked in itself helped educate me about glazes. I'm mostly familiar
with Hyperglaze for the Mac. It came with a great tutorial that taught
me about glazes so that I could use the software more efficiently. I
too am not great with numbers - with the software, I could relax. It
did the numbers for me, I just had to know enough to interpret them (and
it gave me enough info so I could so that).
Jonathan in rainy DC
sacredclay wrote:
> This was a helluva interesting read, namely because I've realized by
> now that it's incredibly interesting to misread the intentions behind
> the wordsand like some, have even bristled (and loudly,too) at some
> of the responses that were meant to educate, not deride me. On the
> side note, I apologize to Dolita for reacting like that.)But I
> digress, as usual.My question springs from the Glazemaster
> claculations. I've never used that, or any other programs that deals
> with that simply because I'm not that knowledgable about computers,
> but also numbers frighterns me becasue I can't get my head around
> them at times.I know formulas should equal about 100.00. I know that
> more than 5% of Bentonite isn't good. I now know that more than 5%
> copper isn't that safe.Repetition will help. What I want to know is
> that if the Glazemaster calculates a recipe,will it also tells me
> that it's either correct or incorrect? Will it also tells me what I
> need to do to correct a problem? does it just list recipes? What else
> can it do? the silica Alumian ratio doesn't tell me anything. At what
> level should it be in? I'd like to hear from other's experience as to
> what they've found helpful and frusterating with the program. Its'
> not enough to tell me that it's great. All things are advertised
> as "they'rrrr grrrrreat!". Much thanks to all. Kathryn in NC > >with
> urban living.
>
>>> Neither my ideas nor my goofiness came through. What a
>>>
> were, I was under the impression that you would
>
>>> do calculations because you mentioned Glazemaster.
>>> Crazing is about Coefficient of Expansion. We had this
>>> long discussion about quoting COE values and the
>>> ceramists a while back. That's why I bought it up. If
>>> you are not doing calculations, the point is moot. If
>>> you are going to do calculations and compare numbers,
>>>
>
>
>> Yes, absolutely will I calculate the glazes. John and Steve have
>>
> been
>
>> helping me to get my Glaze Master up and running again. I had the
>>
> version
>
>> 1.0 and it did not want to load onto my new computer. Now John and
>>
> Steve
>
>> have worked with me, and as usual, generosity in our community makes
>> things happen.
>> I plan to calculate the glazes.
>>
>>
>>
>
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