Karl P. Platt on tue 15 jul 97
Every week or so someone posts a note here saying things like:
"My glaze turned to jello in the bucket"
"My glaze has these lumps in it it didn't have last week"
"My glaze worked ok the first time, but now it crawls real badly"
"My glaze looks completely different this time"
Such remarks are almost invariably followed by:
"The recipe has Ghastly Borate in it........."
Jeff Lawrence discovered that "In the course of mining borax, the
workers periodically run across chunks that don't feed easily into (the
crusher)... So they toss the hard or big chunks aside onto a pile. When
they have a truckload, they scoop it up in a loader (presumably with
some little extras for the pile site), toss it into a truck and haul it
to where they beat it into powder and put it in bags. They don't monitor
for consistency and they don't perform any refinement ...
I don't know about you, but I want to be in a position to repeat my best
results and Ghastly Borate makes such a thing highly elusive -- if not
impossible. If you're in production and using this stuff, you're asking
to go broke.
Ghastly Borate has lots of soluble material in it -- Borates and
alkalies. This explains the weird things that happen when one puts it in
a slip.
Frits were invented and refined to eliminate such behavior -- and to
allow repeatibility. At least within limits much more narrow than those
of this pariah material. Yes they cost a little more, but the loss of a
single kilnful of ware to this highly fugitive raw material (Ghastly)
more than covers the slight upcharge.
KPP
--
Heisenberg may have been here.......
Craig Martell on wed 16 jul 97
Hi All:
So Karl Platt's aversion to Gerstley Borate is based on probability and
second hand information, not practical experience and experimentation. He
reads posts on glaze problems and because a lot of the glazes contain
Gerstley Borate, that material has to be the culprit. Then, there are
others who write, including myself, who have used Gerstley Borate with good
results. It would seem that Karl is bad mouthing a material that HAS been
used successfully and effectively. Karl's reasons for avoiding Gerstley
Borate do not in any way convince me that I shouldn't use the material. As
Ron Roy correctly pointed out, the Neph Sy in the Berry Rust glaze could
very well be the offending material. People who use porcelain bodies fluxed
with Neph Sy have to use a newly mixed batch of clay within a couple of
months or the Neph Sy deflocculates the clay. So much for aging! Karl's
comment that anyone using GB in production is asking to go broke is a wild
stretch of the imagination at best.
Sources of Calcium Borate are pretty limited. We can use GB, Colemanite (if
you can find it), and Calcium Borate frits. Jeff Lawrence's comment about
his conversation with the guy from the Ferro Corp. may very well be factual,
or the Ferro guy may have been embellishing the story. After all, if
potters use GB, they aren't going to be buying Ferro Frits. Yes, I know
that potters buy such a small quantity of materials in comparison with
industry that Ferro probably doesn't give a shit if we buy their stuff or
not but they still may not want to give any credence to Borax mining "by
products".
For my own info, I'm going to call Indusrial Minerals on friday an see if I
can get their "embellishment" on the all this brew ha ha. I will also test
the Berry Rust glaze by using the original formula with Gerstley Borate and
the recalculated version with frits. I for one, would like to make some
first hand observations about this stuff. If you guys want me to, I'll post
the results to Clayart along with formulas etc. If not, I'll just go on my
merry way testing and trying to find out some "solid" facts. I guess it
seems like I'm on some kind of Crusade, but really, I'm just curious.
Sorry about the edgy nature of this post but I've been listening to Howlin'
Wolf and Screamin' Jay Hawkins again. Craig Martell-Oregon
Karl P. Platt on thu 17 jul 97
>So Karl Platt's aversion to Gerstley Borate is based on probability and
>second hand information, not practical experience and experimentation.
Nco me provocar, cara. Where do you get off making a crack like that? I
come out here trying to lend my practical experience to the cause of
creativity and small enterprise, then here comes some "bobaca" making
this kind of noise. Bohah. Look, bud, I've probably consumed more
ghastly borate in an afternoon than you'll see in your career -- but
only once -- it's problematic. The material is fugitive, it is widely
known to be variable and soluble and has no cost-effective role in
production ceramics -- regardless of scale.
The references to Clayart posts are simply there as a matter of
establishing context.
>...the Neph Sy in the Berry Rust glaze could
>very well be the offending material.
If we're to discuss probablilies, the NS option is much smaller than the
Ghastly. NS does contain soluble alkali, however, this does not explain
the thixotropy typically imparted to ceramic slips by ghastly borate. In
the first place, the net amount of soluble material in NS is many times
less than those found in GB. If you want to experiment, do this:
Take two clean containers and add 1 L of distilled water to each. The
put 1 lb of NS in one and 1 Lb of ghastly in the other. Mix the
powder/water to ensure good solution of all the soluble stuff -- you
could let it sit for a day or two covered as well. After this, shake it
up again to suspend all of the solids and then pour the suspension
through a coffee filter to take out the solids. Then take the liquid and
boil off the water. Quick! Which will have the largest quantity of
residue?
Furthermore, it must be stated clearly that the nature of the soluble
materials in GB are entirely different in nature to those found in a
Syenite. Observe that depending on how the glaze is deflocculated
additional alkali would have the effect of making the slip thicker or
thinner -- as it were. Perhaps more or less viscous would be a better
way to put it. I have never seen an alkali imbalance cause thixotropy
and thixotropy is normally inparted by Ghastly.
There are clear reasons for this, but I don't have time at the moment to
go over them -- and I'm not sure anyone would care to hear it.
>After all, if potters use GB, they aren't going to be buying Ferro >Frits.
Man, I hope your constipation went away.........
Time to establish context again. The Ferro plant down in the city of
Criciuma, 90 Km south of here has 4 furnaces each of which produces
about 80 tons frit/day -- ou seja, the plant produces 320 tons/day. All
of this is made to order. Now, if 20,000 studio ceramists each consume 5
Lb of frit each month, this consumption would have the effect of
sustaining the operation in Criciuma for 15 hours/month or 1 week/year.
This is only one of "n" plants Ferro operates.
In short, Ferro has no clear financial interest in studio potting.
What is important is to observe that Ferro does not toss Ghastly Borate
into their frit furnaces. Why? Well, 5 ton lots of useless frit
ultimately add-up to a lot of wasted resources and a disposal problem --
and this says nothing to hacked-off customers.
I will also note that in my work with high firing (cone 6) CdSSe glazes
- which was not an imaginary exersize. Go to the MTA Herald Square
subway stop in Manhattan to see these tiles -- I tried using several
specialty frits from Ferro which were made in Turkey -- no EPA there.
Ferro was not in a position to guarantee the results of the glaze unless
they furnished a "complete" glaze -- ie frit, clay, other minerals, etc.
Why? Because they were using Calcium Borate and it's properties varied
-- badly. Each lot had to be tested through firing, etc.
> If you guys want me to, I'll post the results to Clayart along with >formulas
This would be interesting. Please copy me privately as I have set
Clayart to nomail for a while.
I also note in today's post that this Berry something glaze contains
bone ash -- more likely tri-calcium phosphate. This, too is a highly
soluble material, but it would not likely cause thixotropy. It would,
however, meddle with the approach to deflocculation.
Karl P. Platt -- hoping Craig had a better day today.
--
Heisenberg may have been here.......
Ric Swenson on thu 17 jul 97
Clayarters,
I started work on a short research project regarding Gerstley Borate today.
The first thing I learned from the US BORAX people is that they are not
mining it any more. They figure they have a 5 to 10 year supply if G.B.
HOWEVER...FEAR NOT....they have and will "always" have OTHER boron bearing
stuff that will be available which will do the jobs we need/want done . (we
shall see).
We might note here that Boron and Bismuth (^$?) are starting to replace
lead in the tableware industry ( p. 76, CERAMIC INDUSTRY, April 97
"Solutions to lead glazes are brought to the table", by Phillip Jackson,
PhD, Ceram Research, Stoke -on -Trent.) Worth the read.
I will, continue to seek the Ghastley Gerstley Guru...a Dr. Wu in
California manana por la manana.
Not to worry....yet...Gerstley Borate fans.
Buy "futures" in G.B. ?
Happy potting.
Ric
----------------------------Original message----------------------------
>Hi All:
>
>So Karl Platt's aversion to Gerstley Borate is based on probability and
>second hand information, not practical experience and experimentation. He
>reads posts on glaze problems and because a lot of the glazes contain
>Gerstley Borate, that material has to be the culprit. Then, there are
>others who write, including myself, who have used Gerstley Borate with good
>results. It would seem that Karl is bad mouthing a material that HAS been
>used successfully and effectively. Karl's reasons for avoiding Gerstley
>Borate do not in any way convince me that I shouldn't use the material. As
>Ron Roy correctly pointed out, the Neph Sy in the Berry Rust glaze could
>very well be the offending material. People who use porcelain bodies fluxed
>with Neph Sy have to use a newly mixed batch of clay within a couple of
>months or the Neph Sy deflocculates the clay. So much for aging! Karl's
>comment that anyone using GB in production is asking to go broke is a wild
>stretch of the imagination at best.
>
>Sources of Calcium Borate are pretty limited. We can use GB, Colemanite (if
>you can find it), and Calcium Borate frits. Jeff Lawrence's comment about
>his conversation with the guy from the Ferro Corp. may very well be factual,
>or the Ferro guy may have been embellishing the story. After all, if
>potters use GB, they aren't going to be buying Ferro Frits. Yes, I know
>that potters buy such a small quantity of materials in comparison with
>industry that Ferro probably doesn't give a shit if we buy their stuff or
>not but they still may not want to give any credence to Borax mining "by
>products".
>
>For my own info, I'm going to call Indusrial Minerals on friday an see if I
>can get their "embellishment" on the all this brew ha ha. I will also test
>the Berry Rust glaze by using the original formula with Gerstley Borate and
>the recalculated version with frits. I for one, would like to make some
>first hand observations about this stuff. If you guys want me to, I'll post
>the results to Clayart along with formulas etc. If not, I'll just go on my
>merry way testing and trying to find out some "solid" facts. I guess it
>seems like I'm on some kind of Crusade, but really, I'm just curious.
>
>Sorry about the edgy nature of this post but I've been listening to Howlin'
>Wolf and Screamin' Jay Hawkins again. Craig Martell-Oregon
Ric Swenson, Bennington College, Route 67-A, Bennington, Vermont,
05201-6001 USA. telephone 802 442 - 5401 vox X 262 fax X 237
direct fax line
802 442 - 6164
email rswenson@bennington.edu
Craig Martell on fri 18 jul 97
Hi Karl:
Thanks for the colorful use of Portugese. I speak Spanish well enough to
pick up a bit of Portugese, so I know what you called me. I try not to take
things too personally and I can imagine why you would be a bit disgusted
with my attitude toward your GB posts, not that my opinion on anything is
liable to affect you in any way.
It seems to me that if you are going to question the value of any material
we use in any level of production, there needs to be some real hard
practical as well as academic data. You sometimes come on pretty heavy with
your opinions about stuff without giving solid reasoning about your
"experience" with the material. I don't know what your level of experience
with pottery is but I have the feeling that you've never done much hands on
studio work ie. glaze mixing, application, and trouble shooting. I have,
for the last 22 years. I don't know everything, there is always a lot to
learn and I try not to let pride get in the way of learning. It is
difficult for studio potters to devote a huge amount of time to ceramic
science because of the economic factor. I do the research when I can
because I like learning about the materials I use and want my work to be
suitable for the purpose intended. Whatever you think about me and my
response to your posts is your own affair and it really doesn't bother me.
I do good work and I understand my materials and the processes that I use to
make the work. So, Bobaca or not, constipated or not, I'm very content with
things.
When I was a kid, my dad once told me that if a person had to resort to name
calling and innuendo about another persons opinion, they were too warped at
the moment to be taken seriously, or had no real solid stance on the subject
anyway. You present a lot of molecular level data to Clayart in a tone which
seems very arrogant. Information given in such a manner is not given in the
spirit of sharing and helping to further a craft, but smacks of self
agrandizement. My opinion is that you enjoy hearing yourself distribute
esoteric technical facts.
By the way, I was and still am having a good day. My disagreement with your
opinion of Gerstley Borate was not based on personal problems, or that I was
not having a pleasant day. I just don't agree with you, or your use of
rhetoric.
I hope you are having a good day, Craig Martell
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