Paul on tue 29 apr 03
Hello,
There is a commercial stoneware body i used to use but now i have to drive
over an hour to get it and i would like to make a body similar to it and mix
it myself. It is the Standard Ceramics 153 body. I don't need to copy it
exactly, but i just want something similar because that is what i have been
using and it works for me. Is it possible to have a chemical analysis done
and from that, calculate an approximate clay body formula? Please let me
know. Thanks,
Paul B
Logan Oplinger on thu 8 may 03
Hello Paul,
I'm sorry to respond to your inquiry so late.
A chemical analysis alone will not provide you with the information you
need to duplicate a clay body.
Each commercial clay body is often made up of a blend of different raw
clays and non-clay ingredients. In terms of chemical make-up, each one can
contribute some of the same materials as the others (SiO2, Al2O3 Fe2O3,
etc.), but in different proportions. Each raw ingredient can also
contribute different materials (TiO2, CaSO4, Na2O, CaO, K2O, etc.).
However, much in the way of desired properties of a clay body are physical
in nature, plasticity, shrinkage, porosity, "tooth", etc., which cannot be
determined solely by chemical analysis. It will also be necessary to do an
analysis to determine what clay minerals are present (there can be several
different clay minerals), the proportion, and the particle size
distribution; as well as the non-clay minerals/materials.
Different raw ingredients are blended to create a clay body with the
desired physical character, from workability to glaze fit.
IMHO, it may be more effective if you were to find or test different clay
body formulas. Go to different ceramic texts, or ask clay suppliers about
obtaining samples of different clay bodies, and modify one or more to suit
your needs.
I hope you find what you need.
Respectfully,
Logan Oplinger
Another Pacific Island
Lat. 13.28 N, Long. 144.45 E.
On Tue, 29 Apr 2003 10:58:09 -0400, Paul wrote:
>Hello,
>There is a commercial stoneware body i used to use but now i have to drive
>over an hour to get it and i would like to make a body similar to it and
mix
>it myself. It is the Standard Ceramics 153 body. I don't need to copy it
>exactly, but i just want something similar because that is what i have been
>using and it works for me. Is it possible to have a chemical analysis done
>and from that, calculate an approximate clay body formula? Please let me
>know. Thanks,
>Paul B
>
>___________________________________________________________________________
___
>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.
Ron Roy on sun 11 may 03
While I respect what Logan is saying here I also don't think the analysis
of a clay body is useless in this respect. Let me try and explain.
Every once in a while a material which is used in the bodies I monitor
becomes unavailable. When I start looking for a replacement I look at the
properties of the material I have to replace - and the most important are
the the chemical properties even if it is a clay.
Shrinkage, drying and working properties can always be adjusted if you
understand what each material brings to the body. Another good reason for
having many materials in a body - adjustment is easier - the body will be
more stable over the years and chances of having a good particle size
distribution are maximized. In Fact - when approached in this way the
chances are good the body will be even better.
Let me use an example.
The high iron clay (like Calvert) is no longer available. I look around for
a clay with similar amounts of iron in the analysis - it does not mater
about maturity or particle size - I can adjust that later if need be. What
I need to start with is a body that will mature at the proper cone and have
the same colour - that part is best done looking at the molecular formula.
Over the years I have used different ways of substituting in different
material to clay and glazes - nothing works as well as trying to duplicate
mol for mol. When adjusting the working properties you simply keep an eye
on the mols using your handy calculation software.
RR
>A chemical analysis alone will not provide you with the information you
>need to duplicate a clay body.
>
>Each commercial clay body is often made up of a blend of different raw
>clays and non-clay ingredients. In terms of chemical make-up, each one can
>contribute some of the same materials as the others (SiO2, Al2O3 Fe2O3,
>etc.), but in different proportions. Each raw ingredient can also
>contribute different materials (TiO2, CaSO4, Na2O, CaO, K2O, etc.).
>
>However, much in the way of desired properties of a clay body are physical
>in nature, plasticity, shrinkage, porosity, "tooth", etc., which cannot be
>determined solely by chemical analysis. It will also be necessary to do an
>analysis to determine what clay minerals are present (there can be several
>different clay minerals), the proportion, and the particle size
>distribution; as well as the non-clay minerals/materials.
>Different raw ingredients are blended to create a clay body with the
>desired physical character, from workability to glaze fit.
>
>IMHO, it may be more effective if you were to find or test different clay
>body formulas. Go to different ceramic texts, or ask clay suppliers about
>obtaining samples of different clay bodies, and modify one or more to suit
>your needs.
>
>I hope you find what you need.
>
>Respectfully,
>
>Logan Oplinger
>Another Pacific Island
>Lat. 13.28 N, Long. 144.45 E.
>
>
>On Tue, 29 Apr 2003 10:58:09 -0400, Paul wrote:
>
>>Hello,
>>There is a commercial stoneware body i used to use but now i have to drive
>>over an hour to get it and i would like to make a body similar to it and
>mix
>>it myself. It is the Standard Ceramics 153 body. I don't need to copy it
>>exactly, but i just want something similar because that is what i have been
>>using and it works for me. Is it possible to have a chemical analysis done
>>and from that, calculate an approximate clay body formula? Please let me
>>know. Thanks,
>>Paul B
>>
>>___________________________________________________________________________
>___
>>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.
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Phone: 613-475-9544
Fax: 613-475-3513
| |
|
