Craig Martell on mon 13 apr 98
Hi:
This will hopefully be of interest to those doing midfire glazes and lower.
I have done some line blends with custer spar and cady cal 100, which is a
new boron product produced by Ft.Cady Minerals with some marketing help from
the Feldspar Corp. in Atlanta, Ga. Feldspar Corp. produces G-200 spar and
EPK, plus a lot of othe stuff.
Anyway, the fusions are quite similar and when the Cady Cal is in the ratio
of 75% Custer to 25% Cady Cal, there is a somewhat brighter and smoother
fusion than is obtained with Gerstley Borate. I should mention that I did
identical blends with Custer and Gerstley Borate for the sake of comparison.
I found the fusion rates to be very close between the two. The fusion
buttons were prepared by dry mixing and packing into a Coors 000 Crucible,
which is about the size of a sewing thimble. Color response tests are next.
The supposed advantage to Cady Cal 100 is a very consistent analysis and no
reaction with the glaze slop, which is sometimes a real pain in the butt
with Gerstley Borate. Gerstley Borate is also quite variable in analysis
and the results can be somewhat dicey. Cady Cal 100 will cost less than
Calcium-Borate frits.
I have gotten samples of Cady Cal 100 from Georgies Ceramic and Clay in
Portland, Oregon. Their Phone is 1-800-999-clay. If you want to get info
from The Feldspar Corp., e-mail them at >sales@zemex.com<
hope this is of interest, Craig Martell-Oregon USA
Bert A Stevens on tue 14 apr 98
what about using the Cady Cal 100 as a clay body flux??
Craig Martell on wed 15 apr 98
At 07:52 AM 4/14/98 EDT, Bert wrote:
>----------------------------Original message----------------------------
>what about using the Cady Cal 100 as a clay body flux??
Hi Bert:
What temperature?? Actually, this stuff is mostly Boron and Calcium and you
would be better off using some sort of feldspar or talc as body fluxes.
I've actually not heard of using a Boron mineral for fluxing clays. Has
this been done before?? I'll post the Cady Cal 100 analysis below. It was
sent to me by William Rodgers of Zemex(Feldspar)Corp. later, Craig
Martell-Oregon
Typical analysis of Cadycal 100 is as follows:
B2O3 >48%
Cl <0.1%
SO3 <0.1%
As2O3 Not Detected
SiO2 <1.0%
Fe2O3 <0.08%
CaO 28%
Na2O <0.1%
Al2O3 <0.2%
K2O <0.03%
MgO <0.3%
SrO <0.04%
Moisture <2.0%
Susan Raku on wed 15 apr 98
Are you saying that you can make direct substitutes with the 25/75 mix? What
about the visual changes?
susan
Craig Martell on thu 16 apr 98
At 08:24 AM 4/15/98 EDT, Susan wrote:
>----------------------------Original message----------------------------
>Are you saying that you can make direct substitutes with the 25/75 mix? What
>about the visual changes?
Hi:
I was just passing along some general info about the fusion rates of a
Custer and Cadycal line blend vs. the same line blend done with Gerstley
Borate. Both materials had similar influence on the fusion rate of Custer
spar at cone 6 Ox. The 75 custer/25 cadycal mix showed good fusion and was a
bit smoother and less crazed than the mix with 25% gerstley borate. From my
observation of the fusions, I would say that yes, you can make a direct
substitution for SOME Gerstley Borate batches but the stuff is so variable
that I would be hard pressed to make any accurate predictions as to whether
or not it would fuse at the same rate as anyone elses batch of Gerstley Borate.
Cadycal is very new on the market and needs to be tested before anyone can
make any real solid predictions as to how to sub for other boron ingredients
that are currently being used. It does sound like this stuff is a lot more
user friendly than GB, and will hold a much more consistent analysis. If it
continues to test well, I would used it any day, over Gerstley Borate. The
visual changes remain to be seen after many tests.
regards, Craig Martell-Oregon
David Hewitt on sun 19 apr 98
In message , Craig Martell writes
>----------------------------Original message----------------------------
>At 07:52 AM 4/14/98 EDT, Bert wrote:
>>----------------------------Original message----------------------------
>>what about using the Cady Cal 100 as a clay body flux??
>
>Hi Bert:
>
>What temperature?? Actually, this stuff is mostly Boron and Calcium and you
>would be better off using some sort of feldspar or talc as body fluxes.
>I've actually not heard of using a Boron mineral for fluxing clays. Has
>this been done before?? I'll post the Cady Cal 100 analysis below. It was
>sent to me by William Rodgers of Zemex(Feldspar)Corp. later, Craig
>Martell-Oregon
>
>Typical analysis of Cadycal 100 is as follows:
>
>B2O3 >48%
>Cl <0.1%
>SO3 <0.1%
>As2O3 Not Detected
>SiO2 <1.0%
>Fe2O3 <0.08%
>CaO 28%
>Na2O <0.1%
>Al2O3 <0.2%
>K2O <0.03%
>MgO <0.3%
>SrO <0.04%
>Moisture <2.0%
>
This analysis looks remarkably similar to that of Colemanite.
Foresight gives the following for Colemanite.
CaO 27.3%
B2O3 50.8%
LOI 21.9%
In either case, the analysis above would make it similar to Gerstley
Borate. Foresight gives the following analysis:-
CaO 16.85%
B2O3 52.25%
Na2O 9.31%
LOI 21.59%
Is Cadycal 100 a mined material or a frit? If it is a frit, then would I
be correct in concluding that this is why it gives more consistent
results than Gerstley Borate?
It may surprise some readers of Clayart if I said that it is quite a
rarity to find a UK potter using either Gerstley Borate or Colemanite.
A fritted material providing the necessary boron etc. is the more usual
route adopted because of consistency and cost.
--
David Hewitt
David Hewitt Pottery ,
7 Fairfield Road, Caerleon, Newport,
South Wales, NP6 1DQ, UK. Tel:- +44 (0) 1633 420647
Own Web site http://www.dhpot.demon.co.uk
IMC Web site http://digitalfire.com/education/people/hewitt.htm
Craig Martell on tue 21 apr 98
At 10:56 AM 4/19/98 EDT, David Hewitt wrote:
>Is Cadycal 100 a mined material or a frit? If it is a frit, then would I
>be correct in concluding that this is why it gives more consistent
>results than Gerstley Borate?
Hi David:
Cadycal 100 is a mined mineral.
regards, Craig Martell-Oregon
pedresel@3-cities.com on fri 24 apr 98
>Is Cadycal 100 a mined material or a frit? If it is a frit, then would I
>be correct in concluding that this is why it gives more consistent
>results than Gerstley Borate?
I believe Cadycal is solution-mined. Basically you pump hot water or some
solution into the ground to disolve the mineral then pump it back to the
surface as a liquid and precipitate it back out. Has some real advantages
in cost as well as improving the purity of the product. Most of the nasties
are left behind in the process.
I guess I will have to get some on my next Portland run. I would be
interested if it has the same physical effects in the glaze slop. Doesn't
gb aid in keeping things in suspension and help produce a tough surface on
the unfired glaze? Could be an advantage over frits.
-- Evan in W. Richland WA where some perverse aspect of my nature has me
hand digging the garden rather than getting the neighbor over with his
tractor mounted tiller that could do my tiny plot in 2 minutes.
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