Gordana Ricijas on tue 26 mar 02
I have some disagreement with my friend about calculating unity formula. When I use a program for calculating unity formula, I enter a chemical analyses for each raw material with LOI, for example: withening: % 56.35CaO, 0.09SiO2, 43.56LOI (suma 100)
My friend try to convince me that I'm wrong and that I have to enter raw material without LOI, and precalculate analyses on 100%, for example withining: % 99.84CaO, 0.16SiO2 (suma 100).
Because of that we get a different unity formula. Who's right?
Thank you for your help. Bye. Gordana
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John Hesselberth on tue 26 mar 02
Hi Gordana
You are weighing out and using materials that have an LOI; therefore LOI
should be in the material when you enter it into your material data base.
If, for example, you were using a mixture of calcined and uncalcined clay in
your recipe, you should have two entries in your material data base--one for
each with the difference being that you would not enter LOI for the calcined
material because it doesn't have any. The unity formula for calcined and
uncalcined material will be identical, but the "molecular weight" will be
different
Regards,
John
on 3/26/02 3:58 AM, Gordana Ricijas at goricijas@YAHOO.COM wrote:
> I have some disagreement with my friend about calculating unity formula. When
> I use a program for calculating unity formula, I enter a chemical analyses for
> each raw material with LOI, for example: withening: % 56.35CaO, 0.09SiO2,
> 43.56LOI (suma 100)
>
> My friend try to convince me that I'm wrong and that I have to enter raw
> material without LOI, and precalculate analyses on 100%, for example
> withining: % 99.84CaO, 0.16SiO2 (suma 100).
>
> Because of that we get a different unity formula. Who's right?
>
> Thank you for your help. Bye. Gordana
Web sites: http://www.masteringglazes.com and http://www.frogpondpottery.com
Email: john@frogpondpottery.com
"Art is not a handicraft, it is the transmission of feeling the artist has
experienced." Leo Tolstoy, 1898
David Hewitt on wed 27 mar 02
If you are entering a raw material from percent weight analysis always
include the LOI. Also the Molecular Weight for the Material should be
for this situation. i.e the Raw Mol. Wt.
If you are entering a raw material from a unity formula then LOI does
not enter into it and the Mol Wt. will be different.
David
In message , Gordana Ricijas writes
>I have some disagreement with my friend about calculating unity formula. =
>When I use a program for calculating unity formula, I enter a chemical an=
>alyses for each raw material with LOI, for example: withening: % 56.35CaO=
>, 0.09SiO2, 43.56LOI (suma 100)
>
>My friend try to convince me that I'm wrong and that I have to enter raw=
> material without LOI, and precalculate analyses on 100%, for example =
> withining: % 99.84CaO, 0.16SiO2 (suma 100).
>
>Because of that we get a different unity formula. Who's right?
>
>Thank you for your help. Bye. Gordana
>
>
>
>
>
>
>
>
>
>
>
>
>
>---------------------------------
>Do You Yahoo!?
>Yahoo! Movies - coverage of the 74th Academy Awards=AE
--
David Hewitt
David Hewitt Pottery ,
7 Fairfield Road, Caerleon, Newport,
South Wales, NP18 3DQ, UK. Tel:- +44 (0) 1633 420647
FAX:- +44 (0) 870 1617274
Web site http://www.dhpot.demon.co.uk
Bob Acton on mon 12 nov 07
I received a glaze formula from a friend and I entered it into the =
INSIGHT
glaze calculation software to obtain the unity formula and begin to look =
for
appropriate levels of the ingredients. Given that the recipe was for =
5000
grams I divided it equally to get a smaller amount in order to do a =
sample.
When I did this on each item, the eventual unity calculation had changed
from the one for the 5000 grams! When I had the INSIGHT program =
calculate a
100 grams instead of me dividing each weight by 50 (5000/50=3D100) to =
get my
100 gram sample trial, the unity formula was exactly the same as the
original.
=20
So this leads me to think that a simple reduction of a large sized =
recipe by
simple division isn=92t accurate at the end=85unless one does it by =
molecular
weights or similar.
=20
Any thoughts?
=20
Bob
=20
=20
=20
No virus found in this outgoing message.
Checked by AVG Free Edition.=20
Version: 7.5.503 / Virus Database: 269.15.26/1120 - Release Date: =
09/11/2007
9:26 AM
=20
John Hesselberth on tue 13 nov 07
Hi Bob,
You can scale any recipe by multiplying or dividing each ingredient =20
by the same number and the unity formula will (should) stay the same. =20=
I can't say what happened with Insight since I don't use that program.
Regards,
John
On Nov 12, 2007, at 7:15 PM, Bob Acton wrote:
> So this leads me to think that a simple reduction of a large sized =20
> recipe by
> simple division isn=92t accurate at the end=85unless one does it by =20=
> molecular
> weights or similar.
John Hesselberth
http://www.masteringglazes.com
http://www.frogpondpottery.com
Donna Kat on tue 13 nov 07
On Mon, 12 Nov 2007 17:15:28 -0700, Bob Acton
wrote:
>I received a glaze formula from a friend and I entered it into the INSIGHT
>glaze calculation software to obtain the unity formula and begin to look
for
>appropriate levels of the ingredients. Given that the recipe was for 5000
>grams I divided it equally to get a smaller amount in order to do a
sample.
>When I did this on each item, the eventual unity calculation had changed
>from the one for the 5000 grams! When I had the INSIGHT program calculate
a
>100 grams instead of me dividing each weight by 50 (5000/50=3D100) to get m=
y
>100 gram sample trial, the unity formula was exactly the same as the
>original.
>
>
>So this leads me to think that a simple reduction of a large sized recipe
by
>simple division isn=92t accurate at the end=85unless one does it by molecul=
ar
>weights or similar.
>
>Any thoughts?>
>Bob
Changing the total weight should not change the Unity formula at all. I
believe Insight allows you to change the total and it will then change to
individual weights itself. I suggest you recheck your own calculations if
you did this by hand.
Donna
Bill Merrill on tue 13 nov 07
The key when recalculating a unity formula to batch and using different
feldspars etc. is to remember using different materials will change the
percentage of that material compared to the original glaze. =20
=20
Many people talk about "32" or mamo mat. #32 is the high alumina glaze
listed in Dan Rhodes book " Clay and Glazes for the Potter" The unity
formula is listed with the glaze. The original spar used for that glaze
was Oxford spar from Maine. If that glaze is calculated from unity to
batch using another feldspar etc. numerous relationships will change
compared to the original. I don't remember what clay was used in that
glaze. If one is to use the unity to batch method for calculating
glazes, you will need the formula for each material you use as their
molecular relationships vary unless the program you are using has all of
that information.
=20
Picasso said "computers aren't any good as they can only answer
questions"
=20
=20
=20
=20
=20
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