Roger Korn on sun 17 mar 02
Hi Paul,
How do I get David Hewitt's address? I'd like to get a copy of his "Glaze
Workbook".
Thanks,
Roger
Paul Lewing wrote:
> on 3/17/02 11:00 AM, j.a.velez at j.a.velez@COX.NET wrote:
>
> > It appears to me that using a spread sheet
> > (Excel) one can do these calculation of going from a batch recipe to the
> > unit formula and vice versa fairly easy.
>
> Jose, don't reinvent the wheel. David Hewitt's already done this, expansion
> numbers and all. His Glaze Workbook is actually a set of Excel macros. For
> $23 US, you'd be money ahead to not do it yourself.
> Paul Lewing,
> who got home from NCECA yesterday, slept 12 hours last night, and is still
> tired.
>
> ______________________________________________________________________________
> 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.
--
Roger Korn
McKay Creek Ceramics
In AZ: PO Box 463
4215 Culpepper Ranch Rd
Rimrock, AZ 86335
928-567-5699 <-
In OR: PO Box 436
31330 NW Pacific Ave.
North Plains, OR 97133
503-647-5464
j.a.velez on sun 17 mar 02
I have a question about the computer programs for glaze calculations. I
have read John and Ron's appendix on this issue and just re-read Rhodes'
section on glaze calculations (old edition) and also perused through Zakin's
chapter on the same issue. It appears to me that using a spread sheet
(Excel) one can do these calculation of going from a batch recipe to the
unit formula and vice versa fairly easy. So, I am tempted to do my own.
The only thing I have not seen in these references is how to predict the
coefficient of thermal expansion of the resulting glaze, which is a
significant piece of information. Is this calculated for the mix based on
the single oxides empirical data? How is it done, is it pro-rated based on
composition, or does it obey a more complicated, but predictable function?
Also in the prediction of the fusion temperatures do these programs take
into account the eutectic from some large empirical data base or do they
interpolate based on the limit formulas?
I believe that doing the program will clarify these concepts and the theory
behind the use of each of these materials will become clear and could be a
significant asset once is combined with the actual practice of formulating
and using the glaze. Of course you don't need the computer to learn this,
but I can learn and finish with a program at the same time. Has anybody
done this? Would you care to comment?
Regards, Jose A. Velez
Terrance Lazaroff on sun 17 mar 02
Jose;
I put together a program along the lines of what you are discussing and I
too got lost when it came to the expansion stuff. My program was in the
old visicalc language. It worked quite well for the number crunching.
I have long lost the program with the changes that came about in spreadsheet
technology.
Terrance
----- Original Message -----
From: "j.a.velez"
To:
Sent: Sunday, March 17, 2002 2:00 PM
Subject: Computer Programs for Glaze Calculations
> I have a question about the computer programs for glaze calculations. I
> have read John and Ron's appendix on this issue and just re-read Rhodes'
> section on glaze calculations (old edition) and also perused through
Zakin's
> chapter on the same issue. It appears to me that using a spread sheet
> (Excel) one can do these calculation of going from a batch recipe to the
> unit formula and vice versa fairly easy. So, I am tempted to do my own.
> The only thing I have not seen in these references is how to predict the
> coefficient of thermal expansion of the resulting glaze, which is a
> significant piece of information. Is this calculated for the mix based on
> the single oxides empirical data? How is it done, is it pro-rated based
on
> composition, or does it obey a more complicated, but predictable function?
> Also in the prediction of the fusion temperatures do these programs take
> into account the eutectic from some large empirical data base or do they
> interpolate based on the limit formulas?
>
> I believe that doing the program will clarify these concepts and the
theory
> behind the use of each of these materials will become clear and could be a
> significant asset once is combined with the actual practice of formulating
> and using the glaze. Of course you don't need the computer to learn this,
> but I can learn and finish with a program at the same time. Has anybody
> done this? Would you care to comment?
>
> Regards, Jose A. Velez
>
>
____________________________________________________________________________
__
> 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.
Bill Arnold on sun 17 mar 02
Use the procedure for calculating coefficiant of expansion that is outlined
in Parmalee
----- Original Message -----
From: "j.a.velez"
To:
Sent: Sunday, March 17, 2002 2:00 PM
Subject: Computer Programs for Glaze Calculations
> I have a question about the computer programs for glaze calculations. I
> have read John and Ron's appendix on this issue and just re-read Rhodes'
> section on glaze calculations (old edition) and also perused through
Zakin's
> chapter on the same issue. It appears to me that using a spread sheet
> (Excel) one can do these calculation of going from a batch recipe to the
> unit formula and vice versa fairly easy. So, I am tempted to do my own.
> The only thing I have not seen in these references is how to predict the
> coefficient of thermal expansion of the resulting glaze, which is a
> significant piece of information. Is this calculated for the mix based on
> the single oxides empirical data? How is it done, is it pro-rated based
on
> composition, or does it obey a more complicated, but predictable function?
> Also in the prediction of the fusion temperatures do these programs take
> into account the eutectic from some large empirical data base or do they
> interpolate based on the limit formulas?
>
> I believe that doing the program will clarify these concepts and the
theory
> behind the use of each of these materials will become clear and could be a
> significant asset once is combined with the actual practice of formulating
> and using the glaze. Of course you don't need the computer to learn this,
> but I can learn and finish with a program at the same time. Has anybody
> done this? Would you care to comment?
>
> Regards, Jose A. Velez
>
>
____________________________________________________________________________
__
> 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.
>
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Paul Lewing on sun 17 mar 02
on 3/17/02 11:00 AM, j.a.velez at j.a.velez@COX.NET wrote:
> It appears to me that using a spread sheet
> (Excel) one can do these calculation of going from a batch recipe to the
> unit formula and vice versa fairly easy.
Jose, don't reinvent the wheel. David Hewitt's already done this, expansion
numbers and all. His Glaze Workbook is actually a set of Excel macros. For
$23 US, you'd be money ahead to not do it yourself.
Paul Lewing,
who got home from NCECA yesterday, slept 12 hours last night, and is still
tired.
Paul Lewing on mon 18 mar 02
on 3/17/02 10:06 PM, Roger Korn at rogerk1941@EARTHLINK.NET wrote:
> How do I get David Hewitt's address? I'd like to get a copy of his "Glaze
> Workbook".
It's david@dhpot.demon.co.uk.
Paul Lewing, Seattle
John Weber on mon 18 mar 02
Jose, I agree with Paul Lewing, don't reinvent the wheel. You can go with
his approach or get some very good glaze calculation software from Robert
Wilt for the full cost of $35. His link is http://www.dinoclay.com/ Good
luck.
-----Original Message-----
From: Ceramic Arts Discussion List [mailto:CLAYART@LSV.CERAMICS.ORG]On
Behalf Of j.a.velez
Sent: Sunday, March 17, 2002 2:00 PM
To: CLAYART@LSV.CERAMICS.ORG
Subject: Computer Programs for Glaze Calculations
I have a question about the computer programs for glaze calculations. I
have read John and Ron's appendix on this issue and just re-read Rhodes'
section on glaze calculations (old edition) and also perused through Zakin's
chapter on the same issue. It appears to me that using a spread sheet
(Excel) one can do these calculation of going from a batch recipe to the
unit formula and vice versa fairly easy. So, I am tempted to do my own.
The only thing I have not seen in these references is how to predict the
coefficient of thermal expansion of the resulting glaze, which is a
significant piece of information. Is this calculated for the mix based on
the single oxides empirical data? How is it done, is it pro-rated based on
composition, or does it obey a more complicated, but predictable function?
Also in the prediction of the fusion temperatures do these programs take
into account the eutectic from some large empirical data base or do they
interpolate based on the limit formulas?
I believe that doing the program will clarify these concepts and the theory
behind the use of each of these materials will become clear and could be a
significant asset once is combined with the actual practice of formulating
and using the glaze. Of course you don't need the computer to learn this,
but I can learn and finish with a program at the same time. Has anybody
done this? Would you care to comment?
Regards, Jose A. Velez
____________________________________________________________________________
__
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.
Wanda Holmes on mon 18 mar 02
Jose, I built my own utility using Excel. It was a great way to really
learn and reinforce the materials, calculations, and basics of glaze
chemistry. In the end, however, I bought a glaze calculation program. As a
database for storing glazes that can be compared, adjusted, tested, and
documented, programs such as Insight or GlazeChem are head and shoulders
above Excel. Well worth the money. Wanda
-----Original Message-----
From: Ceramic Arts Discussion List [mailto:CLAYART@LSV.CERAMICS.ORG]On
Behalf Of John Weber
Sent: Monday, March 18, 2002 6:57 AM
To: CLAYART@LSV.CERAMICS.ORG
Subject: Re: Computer Programs for Glaze Calculations
Jose, I agree with Paul Lewing, don't reinvent the wheel. You can go with
his approach or get some very good glaze calculation software from Robert
Wilt for the full cost of $35. His link is http://www.dinoclay.com/ Good
luck.
-----Original Message-----
From: Ceramic Arts Discussion List [mailto:CLAYART@LSV.CERAMICS.ORG]On
Behalf Of j.a.velez
Sent: Sunday, March 17, 2002 2:00 PM
To: CLAYART@LSV.CERAMICS.ORG
Subject: Computer Programs for Glaze Calculations
I have a question about the computer programs for glaze calculations. I
have read John and Ron's appendix on this issue and just re-read Rhodes'
section on glaze calculations (old edition) and also perused through Zakin's
chapter on the same issue. It appears to me that using a spread sheet
(Excel) one can do these calculation of going from a batch recipe to the
unit formula and vice versa fairly easy. So, I am tempted to do my own.
The only thing I have not seen in these references is how to predict the
coefficient of thermal expansion of the resulting glaze, which is a
significant piece of information. Is this calculated for the mix based on
the single oxides empirical data? How is it done, is it pro-rated based on
composition, or does it obey a more complicated, but predictable function?
Also in the prediction of the fusion temperatures do these programs take
into account the eutectic from some large empirical data base or do they
interpolate based on the limit formulas?
I believe that doing the program will clarify these concepts and the theory
behind the use of each of these materials will become clear and could be a
significant asset once is combined with the actual practice of formulating
and using the glaze. Of course you don't need the computer to learn this,
but I can learn and finish with a program at the same time. Has anybody
done this? Would you care to comment?
Regards, Jose A. Velez
____________________________________________________________________________
__
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.
____________________________________________________________________________
__
Send postings to clayart@lsv.ceramics.org
You may look at the archives for the list or change your subscription
settings from http://www.ceramics.org/clayart/
Moderator of the list is Mel Jacobson who may be reached at
melpots@pclink.com.
Ababi on mon 18 mar 02
This is his sitehttp://www.dhpot.demon.co.uk/
Ababi
---------- Original Message ----------
>Hi Paul,
>How do I get David Hewitt's address? I'd like to get a copy of his
>"Glaze
>Workbook".
>Thanks,
>Roger
>Paul Lewing wrote:
>> on 3/17/02 11:00 AM, j.a.velez at j.a.velez@COX.NET wrote:
>>
>> > It appears to me that using a spread sheet
>> > (Excel) one can do these calculation of going from a batch recipe
>to the
>> > unit formula and vice versa fairly easy.
>>
>> Jose, don't reinvent the wheel. David Hewitt's already done this,
>expansion
>> numbers and all. His Glaze Workbook is actually a set of Excel
>macros. For
>> $23 US, you'd be money ahead to not do it yourself.
>> Paul Lewing,
>> who got home from NCECA yesterday, slept 12 hours last night, and is
>still
>> tired.
>>
>>
>________________________________________________________________________
>______
>> 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.
>--
>Roger Korn
>McKay Creek Ceramics
>In AZ: PO Box 463
> 4215 Culpepper Ranch Rd
> Rimrock, AZ 86335
> 928-567-5699 <-
>In OR: PO Box 436
> 31330 NW Pacific Ave.
> North Plains, OR 97133
> 503-647-5464
>________________________________________________________________________
>______
>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.
j.a.velez on mon 18 mar 02
Wanda, John, Paul, Bill and Terrance:
Than you for your answer to my post on the captioned subject.
I do realize the commercial products available are good and very reasonably
priced. I just thought, as Wanda and Terrance stated, the experience of
building the program will help me get a deeper understanding of the behavior
of glazes and the interaction of the oxides in the kiln atmosphere. I am
still tempted to go ahead and build my own spread sheet on Excel as a way to
study and learn and maybe go ahead and buy a commercial version anyway.
Although I am a learner and an hour of throwing pots might be better
invested than an hour in front of the computer.
I still have a question about the coefficient of thermal expansion for the
resulting glaze: Is Parmalee the best reference on this matter? I think
the initial edition was published 50 years ago and the last edition 30 years
ago. If the basic science has not changed any, then it is probably so, but
does anybody know of a more recent reference on this matter?
Regards,
Jose A. Velez
Fraser Forsythe on tue 19 mar 02
Writing a program is a great way to learn this stuff. However, be cautioned: it's
endless.
Parmalee used the much of the work of Dietzl. Dietzl did his work in the 1920's.
The explantion for why most
of the info we still use came from this period is that most research was
discontinued after plastics came on the scene.
Until plastics came along industrial ceramics was IT. I think these numbers can be
trusted since an entire industry relied on
them. (Tom Buck would be the man to ask about regarding this level of information)
No one can build a 'once and for all' database of oxide properties because methods
of testing
change, the margin of error is high and when you start applying these oxide
properties to materials
the situation becomes a matter of approximation ONLY. You will find different
numbers in just about every reference you look
at. Practical glaze chemistry is a guide, not a discreet system.
Oxide properties also change depending on how they are constituted in various
materials. Some materials,
like wolastonite, wont entirely break down in the melt. The boron in gerstley
borate or a boron loaded frit
will act as a glassformer at lower temps and a flux at higher temps.
I think glaze chemistry is like stock market stratagies: it's not as important
which system you use, just stick
to it. All a program will do is apply a 'relative' range of cooefficients to a
numerical procedure(s) and give you
a result. In the case of expansion, you really only want to know if your last
adjustment increases or decreases that
value.
Fraser
--
Fraser Forsythe
www.glazeexchange.com
iandol on tue 19 mar 02
Dear Jose A. Velez
You ask <predict the coefficient of thermal expansion of the resulting glaze, =
which is a significant piece of information. Is this calculated for the =
mix based on the single oxides empirical data?>>
You will find information relating to this in the first edition of =
Ceramic Glazes by Cullen Parmelee. Values are based on the assumption =
that sum of the value from each component of the quality being derived, =
proportional to the mass distribution of each of the components =
represents the value of the whole. There is an additional assumption =
that this rule can be applied to any quality.
The general case is P=3D c1x1+c2x2+c3x3.....cNxN in which P is the =
property, c is the percentage weight of each component and x1,x2.x3.xN =
are the appropriate corresponding factors. For the most part these =
factors seem to be computed values which have not been obtained from =
direct measurement. It would, I believe be very difficult to measure the =
real coefficients of thermal expansion of Sodium , Potassium and Lithium =
Monoxides or for many of the other oxides. There are also such anomalies =
to consider as, which value would you select if you were dealing with =
one of the forms of silicon dioxide or how do you deal with chemical =
changes when they occur, for example with those oxides which undergo =
reduction.
For the time being, if is essential to have this information for both =
your mature clays and your fired glazes, either construct or obtain your =
own apparatus to measure this property or rely on the services of Ron =
Roy who has both the equipment and the expertise to use it and interpret =
the information which he delivers. Cullen Parmelee is clear about the =
limitations of using this formula, suggesting that it is only possible =
to get approximate results from such computation. He discusses the =
origins of the errors. Useful reading for interested parties.
The references you quote are what I call "Third Generation Information". =
They give "Filtered Information", in other words, condensations, =
opinions or interpretations. It pays those who are serious about their =
research go back the information base, one of the best and oldest being =
"Chemical Abstracts", to find out who were the prime sources of the =
information we use and to read their writings, and read them critically. =
This can be a long tedious process, but it does get you to information =
which is not accessible via the internet, except at a price.
Best regards,
Ivor Lewis. Redhill, South Australia
j.a.velez on wed 20 mar 02
Fraser, Tom and John:
Thanks for the postings and opinions on the captioned subject.
Regards, Jose A. Velez
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