Bill Edwards on mon 30 jun 03
Some years ago I spoke with Ron Roy about a glaze that
I was working on. It was called LP Matt a ^10
Reduction glaze. I was going to turn that glaze into a
^6 ox glaze or bust. I had calculated till I will blue
in the face and ran test after test. Now Ron didn't
exactly hit the mark either but the work between us
lead to something that helped me discover some
advantages with calculations and certain materials. He
and I don't always agree but we are adults and sooner
or latter it boils down to a hard hearded stand off
mostly of my own making. This has taught me some hard
earned lessons but non the less, I earned them well!
I was working on a book about the same time that I
discovered that John and Ron was due to put one out so
I shelved mine. I already had went head to head in
another business that was rooting for a place on the
market and it was just more costly to pay the price
but at that time I did and I held on to my belief and
eventually had a product that latter took off and done
pretty well for me.
Ron is facing lots and lots of questions but he has a
tag team mate to help out. Mmmm, I should have done
that! Anyways the basis of this story is this - They
are tools out there for most anything a human could
have a need for. Calculation tools are just one of
them. Understanding the proper use of these takes more
than just being able to enter your components and then
it spitting out the results with expectations of
getting exactly what the paper says you should get.
Minerals and mines often change over a period of time.
Its important to find a list of materials that you
feel will be adequate for the vast majority of your
work. It can be as extensive as you like but that
means more work for you. The next step is to watch the
changes for these materials that you purchase and get
the latest information available from the company that
is available and add them to your list or data base
that comes with your glaze calculations software. I
have several analysis for various chemicals but
gerstley is in there more times than I remember right
now. WHY? Because its a variable material. I would
enter it based on whatever was the most current
information when I purchased it. I name each material
as its analyzed so I will know which batch it is from
and there are usually a place to make notes built
right in the system. One listing may say Gerstley
Borate 01/22/96 My notes will tell me the package
information or where I bought it and I can even put
the price in there so I can average how much the
finished glaze cost me to make.
Getting back to the LP Purple, After going over Ron's
information and a stack of my own information I
decided to make a calculations change. The answer was
in front of me the whole time. I fired the glaze and
low and behold it was not only as nice as the ^10 but
surpassed it in brighness and fit and had little
nuances that made it a grand glaze. The studio where I
had been working with clay and mixing their glazes on
occasion and the same place that said I would NEVER
make that change were in for a suprize. We had a
Christmas sale and I un-veiled the newly constructed
glaze that had everyone in the house going back and
forth and discussing and mulling it over. I would have
to say my proudest moment was when one of the TOP
potters in the business came over to me and she told
me that she never thought she would see that glaze in
a ^6ox and that she personally had tried for years to
create a similar glaze. This woman did not give out
accolades at all! Since I did fire ^10 Reduction and
now I fire ^6 Oxidation, I can honestly say that most
all the reduction glazes in my past have now been made
into workable, viable ^6 oxidation glazes with
improvements. Well some, I found ^6 Ox glazes that
stand on their own legs as written/without conversion
and can match anything out there for what they are!
There are some minor differences in some but if the
glaze can't be duplicated and suitable either due to
colour or safety, I work towards one that will closely
provide me a substitute I can live with. I only have
about 15 bulk materials now that I use, seldom use all
of them. I have maybe 10 Oxides and stains that I keep
around. I do have small test batches of chemicals that
I use for testing from time to time but they do not go
into any personal production use. I keep them around
for sourcing information and testing mainly for others
who run into some of the problems I have had in the
past. Really if I wanted to I could reduce that level
of materials even more and still have enough materials
in combination to keep me busy this lifetime and one
more at least. The only reason I have as much as I do
now is the old testing spirit in me is still active at
times and will need a challenge for whatever reason?
Aside from my web site, I will soon make another web
site that will host these changes and new glazes. This
site will be for the very purpose of solidifying the
strong points in calculations tools and when I do take
on a glaze and bring it down a notch from a cone 10 R
to a Cone 6 O it will be helpful for those who might
be interested in seeing it. I have done this for
several in regards to the Chrome Tin Red I make and
while some went out on a limb and tested it and had
great results, others have failed. Did I fail??? I
don't think so since I can replicate this glaze
everytime I want to. I have done it with several
changes in materials and get the results I need but on
occasion I have to re-set my figures and see if there
is something astray with this picky color. But testing
and knowledge in using calculations software is
valuable and people like Ron and Jon and Vince and Dr.
Basterache and countless others have spent a life time
studying and applying this knowledge. Much of the
homework has been done and with a little understanding
and a good bit of physical testing alot of real great
glaze can come from all this. There is little need
left to fight over it or to fight with glazes and
materials that are known to shift between batch to
batch unless you just want something to give you more
anxiety than the last kiln load of pots that came out
messed up or looking alot less than you expected. Also
minor differences have certain levels of acceptance.
HOW MUCH? Thats when you line test or have plenty of
experience calculating and sometimes that won't fix
the problem either. But if you are following mol per
mol it might tell you that the glaze remained in the
area of safety if it was one you was using with known
safety factors that have been covered. But if you
delve outside those limits too far, I would always
suggest another evaluation based on the oxides you
use. I just don't have a need for zinc, lead, cadmium
or lithium. Sorry about this being so long - I seldom
post and I promise not to post again for awhile but
some things just take time and this was one of those
days.
William Edwards
=====
http://www.tallapoosariverpottery.com/
Bill Edwards
PO Box 267
Lafayette, AL, 36862
__________________________________
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Belinda Willis on tue 1 jul 03
Gee, Bill,
You make my mouth water talking about the ^10R glazes you've converted
successfully to ^6ox. Any chance you'll finish that book you started?
There is room for all and I doubt if your book would be an exact copy of
R&J's book. You make me lust for more.
Belinda Willis
Santa Rosa, CA
clayart@DIGITALFIRE.AB.CA on wed 2 jul 03
Here is a detailed page on how to convert a
cone 10 glaze to cone 6 also.
http://www.digitalfire.ab.ca/cermat/education/101.php
-------8<--------
Gee, Bill,
You make my mouth water talking about the ^10R glazes you\'ve converted
successfully to ^6ox. Any chance you\'ll finish that book you started?
There is room for all and I doubt if your book would be an exact copy of
R&J\'s book. You make me lust for more.
Belinda Willis
Santa Rosa, CA
--------
Tony Hansen, Digitalfire Corp.
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