Joseph Herbert on tue 12 jan 99
Cone Composition and other concerns
There have been some questions about the whys and
wherefores of cone temperatures. These may be lost in
the mists of time or hidden in company archives, but we
can make some guesses.
While one can t really know what was going on in the
minds of cone researchers (Cone Heads??) there are some
facts found in the unity compositions of the cones that
are suggestive of what was going on. The truth of the
suppositions I make here could perhaps be confirmed by
the recipes for the cones. These are probably trade
secrets of the Orton foundation and not available.
Anyway, this is what I think:
I think that the cones from 4 to 10 were the first the
researchers worked on. Those cones have the following
Unity Formula characteristics: The fluxes, K2O and CaO
are held constant across the range at 0.3 and 0.7
weight percent. The SiO2 varies from 4 to 10 by steps
of 1. The alumina varies from 0.5 to 1.0 by steps of
0.1. The increment of temperature of melting for the
cones, the thing that started this questioning, is as
follows (in degrees C.): 25, 10, 20, 15, 25, 10.
This suggests to me that the relationship between the
weight percent of SiO2 and the cone number is not a
coincidence. There is clearly no attempt to achieve a
consistent temperature increment. The variation in the
composition, in a regular stepped manner, is the chosen
variation. The melting temperature of the cone is
observed rather than planned. If the actual materials
and recipes were known, a relationship between the
amount of some ingredient and the cone number might be
seen.
Cones 11 through 27 attain hold the weight percent of
fluxes constant at K2O = 0.3 and CaO = 0.7 while the
Al2O3 varies from 1.2 to 20.0 and the SiO2 varies from
12 to 200. In this series the variation of Al2O3 and
SiO2 are smooth but not consistent. The steps start at
0.2 and 2.0 weight percent increase per cone but end
with a step of 7.2 to 20 and 72 to 200 between cones 26
and 27. Again the temperature of maturity gaps between
cones are ragged : 25, 25, 40, 40, 20, 40, 15, 20, 30,
5, 60, 15, 10.
The composition of the cones between 28 and 42 again
varies systematically. The Al2O3 is consistently 1.0
while the SiO2 decreases in steps of 2, 1, 0.5, 0.23,
and finally 0.45 and 0.05. In this series the SiO2
serves as something of a flux for the Al2O3. Again,
the temperature steps show no consistency.
The cones between 010 and 01 are made with K2O, CaO,
Fe2O3, and Al2O3 held constant at 0.3, 0.7, 0.2 and 0.3
weight percent respectively. The remainder of the
material is composed of SiO2 and B2O3 varying as
follows. The sum of the two oxides is always 4.0
weight percent. Each cone number from 010 decreases
the B2O3 by 0.05 weight percent and increases the SiO2
by 0.05 weight percent. This means that the cone 010
is 3.50 SiO2 and 0.50 B2O3 and that cone 01 is 3.95
SiO2 and 0.05 B2O3. Again the temperature steps are
irregular: 40, 15, 30, 30, 25, 20, 30, 15, 15.
The really low temperature cones (022 to 011) contain
lead oxide and sodium oxide. The amounts of Na2O and
PbO are 0.5 weight percent each. The Al2O3 increases
by steps from 0 to 0.8 and the SiO2 increases by steps
from 2.00 to 3.60. the amount of B2O3 is 1.0 for the
whole series. Again the temperature steps are
irregular: 10, 30, 5, 40, 50, 15, 35, 25, 15, 35, 15.
From this I conclude that the recipe variations are
what the researchers and later manufacturers control
while the temperatures of maturity are observed results
of that composition. There is no attempt in the stated
composition of the cones the deviate from the simple
stepwise changes in composition to achieve a particular
melting temperature. I believe the times when the
composition changes in other than regular ways are due
to the regular step changes leading to an
insufficiently large change in melting behavior. So,
to state it simply, the maturity temperature of the
cone is a result of the planned composition rather than
the composition being chosen to produce the maturity
temperature. In addition, I think the stoneware
temperature range was investigated first because it is
relatively simple and of greatest economic importance.
( sanitary ware, sewer pipes, crockery, all salt fired
ware) The cone numbers in the 4 through 10 range show
a simple correlation between silica weight percent and
cone number and were the first to be named. The
bizarre leading zero series was a later and bad
modification. They would have been better off
lettering the lower temperature cones.
That s my story and I m sticking to it.
Joseph Herbert
Joseph.Herbert@att.net
--
Instructional Writer
David Hendley on wed 13 jan 99
Yes, I agree, at least for the cones I've studied
(010 to 10).
When you look at the formulas, it's obvious; and
my experiments with making my own cones have
shown the actual recipes developed from the
formulas are pretty close to the mark.
David Hendley
Maydelle, Texas
At 01:15 PM 1/12/99 EST, you wrote:
>----------------------------Original message----------------------------
>Cone Composition and other concerns
>
>There have been some questions about the whys and
>wherefores of cone temperatures. These may be lost in
>the mists of time or hidden in company archives, but we
>can make some guesses.
>
>While one can t really know what was going on in the
>minds of cone researchers (Cone Heads??) there are some
>facts found in the unity compositions of the cones that
>are suggestive of what was going on. The truth of the
>suppositions I make here could perhaps be confirmed by
>the recipes for the cones. These are probably trade
>secrets of the Orton foundation and not available.
>Anyway, this is what I think:
>
>I think that the cones from 4 to 10 were the first the
>researchers worked on. Those cones have the following
>Unity Formula characteristics: The fluxes, K2O and CaO
>are held constant across the range at 0.3 and 0.7
>weight percent. The SiO2 varies from 4 to 10 by steps
>of 1. The alumina varies from 0.5 to 1.0 by steps of
>0.1. The increment of temperature of melting for the
>cones, the thing that started this questioning, is as
>follows (in degrees C.): 25, 10, 20, 15, 25, 10.
>
>This suggests to me that the relationship between the
>weight percent of SiO2 and the cone number is not a
>coincidence. There is clearly no attempt to achieve a
>consistent temperature increment. The variation in the
>composition, in a regular stepped manner, is the chosen
>variation. The melting temperature of the cone is
>observed rather than planned. If the actual materials
>and recipes were known, a relationship between the
>amount of some ingredient and the cone number might be
>seen.
>
>Cones 11 through 27 attain hold the weight percent of
>fluxes constant at K2O = 0.3 and CaO = 0.7 while the
>Al2O3 varies from 1.2 to 20.0 and the SiO2 varies from
>12 to 200. In this series the variation of Al2O3 and
>SiO2 are smooth but not consistent. The steps start at
>0.2 and 2.0 weight percent increase per cone but end
>with a step of 7.2 to 20 and 72 to 200 between cones 26
>and 27. Again the temperature of maturity gaps between
>cones are ragged : 25, 25, 40, 40, 20, 40, 15, 20, 30,
>5, 60, 15, 10.
>
>The composition of the cones between 28 and 42 again
>varies systematically. The Al2O3 is consistently 1.0
>while the SiO2 decreases in steps of 2, 1, 0.5, 0.23,
>and finally 0.45 and 0.05. In this series the SiO2
>serves as something of a flux for the Al2O3. Again,
>the temperature steps show no consistency.
>
>The cones between 010 and 01 are made with K2O, CaO,
>Fe2O3, and Al2O3 held constant at 0.3, 0.7, 0.2 and 0.3
>weight percent respectively. The remainder of the
>material is composed of SiO2 and B2O3 varying as
>follows. The sum of the two oxides is always 4.0
>weight percent. Each cone number from 010 decreases
>the B2O3 by 0.05 weight percent and increases the SiO2
>by 0.05 weight percent. This means that the cone 010
>is 3.50 SiO2 and 0.50 B2O3 and that cone 01 is 3.95
>SiO2 and 0.05 B2O3. Again the temperature steps are
>irregular: 40, 15, 30, 30, 25, 20, 30, 15, 15.
>
>The really low temperature cones (022 to 011) contain
>lead oxide and sodium oxide. The amounts of Na2O and
>PbO are 0.5 weight percent each. The Al2O3 increases
>by steps from 0 to 0.8 and the SiO2 increases by steps
>from 2.00 to 3.60. the amount of B2O3 is 1.0 for the
>whole series. Again the temperature steps are
>irregular: 10, 30, 5, 40, 50, 15, 35, 25, 15, 35, 15.
>
>From this I conclude that the recipe variations are
>what the researchers and later manufacturers control
>while the temperatures of maturity are observed results
>of that composition. There is no attempt in the stated
>composition of the cones the deviate from the simple
>stepwise changes in composition to achieve a particular
>melting temperature. I believe the times when the
>composition changes in other than regular ways are due
>to the regular step changes leading to an
>insufficiently large change in melting behavior. So,
>to state it simply, the maturity temperature of the
>cone is a result of the planned composition rather than
>the composition being chosen to produce the maturity
>temperature. In addition, I think the stoneware
>temperature range was investigated first because it is
>relatively simple and of greatest economic importance.
>( sanitary ware, sewer pipes, crockery, all salt fired
>ware) The cone numbers in the 4 through 10 range show
>a simple correlation between silica weight percent and
>cone number and were the first to be named. The
>bizarre leading zero series was a later and bad
>modification. They would have been better off
>lettering the lower temperature cones.
>
>That s my story and I m sticking to it.
>Joseph Herbert
>Joseph.Herbert@att.net
>
>
>--
>Instructional Writer
>
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