Paul Raymond on wed 12 may 04
firing
Hi all,
I Hope everyone is well in clay land. I have spent the spring throwing
and testing and making tiles and after a few firings I have some
questions and observations. If anyone would care to respond please copy
me as well as post the list since I get the digest and don't want to
miss anything.
I mixed up a few variations of a glaze from MC6G (the glossy base 2) and
noticed that without colorants this glaze cakes at the bottom of the
bucket quickly. I am surmising that the reason for this is that the
oxides in the other buckets (at 5%) are acting as a deflocculant. Is
this correct?
In my most recent glaze firing I put in 2 pots that were not bisqued.
One came out perfect with no flaws at all, the other crawled a bit. The
one that crawled was a dark red clay and the perfect one was white. Is
the reason for the crawl due to impurities in the darker body? The same
glaze on the same clay when bisqued, was fine.
In regards to single firing, What should I be aware of if I opt to do
this all of the time? It is an appealing idea to me since I could save a
lot of time and energy if I stopped bisquing altogether. I have been
bisquing to cone 06. If I continue to bisque what if I drop the firing
down to cone 012 or 010? What are the implications?
And lastly, How do you develop your glazes? My goal is to have about 6
glazes that I really like and that are my own creations. I once worked
with a potter in Santa Cruz who was staring from scratch in his glaze
development. He settled on a base glaze and then mixed tiny amounts and
set up a grid on a tile with increasing amounts and different kinds of
add's. We probably had a few hundred glazes with which to begin further
tests. Of these hundreds we chose about 20 to test further and then from
those narrowed it down to 5 or 6. He ended up with some stunning glazes.
Essentially what we had were variation on the same glaze. That is to say
one base with different add's. I think that I will follow this route as
well since it is familiar to me. I am, however, interested in other
theories on this topic. Any ideas?
I hope everyone has enjoyed spring. Tennessee had been beautiful and is
only now starting to warm up to those muggy summer days.
Thanks,
Paul Raymond
Franklin, TN
daniel on thu 13 may 04
firing
Hi Paul,
I can't answer much of the post but regarding glaze development here is
what I'm doing currently to get a glaze I developed myself. I'm in the
process of trying two methods.
First I analyzed a bunch of cone 10 (I work at cone 10, hence my
uselessness on your mc6g question) glaze I currently use. I know they fit my
clay, I know they fire ok on our schedules. This was an exercise in glaze
analysis. Fun, long, etc. From that I derived a set of psuedo limit formulae
so that I new what to shoot for in terms of silica, alumina and Si:Al ratio.
I am now just looking at expansions and then I will have a formula to
convert to several different bases using whatever materials are easy for me
to get and then I can test them. This whole thing is an exercise in glaze
development from glaze chemistry. I have not yet quite got there.
The other method I will try shortly is blending my fireplace ash with stuff
that looks interesting, like RedArt, feldspar, granite dust (incidentally,
the great thing about new granite counter tops over formica should be the
relatively greater availability of granite dust for the suburban potter to
play with). This is an exercise in throw it in a bucket and see what gives.
I want to do both.
Incidentally, tonight I should get back some fun glaze tests. I have a
two-three week cycle on some glaze firing turnaround as I work through a
class studio and do not own a kiln. Oh well. We do what we can. Excited to
see them though. Two of them are tiles of grids of glazes a la Greg Daly.
That should be interesting, well I hope so.
Thanx
D
Belmont, California, USA
(ex terra australis)
David Hewitt on fri 14 may 04
firing
In message , Paul Raymond writes
>
>And lastly, How do you develop your glazes? My goal is to have about 6
>glazes that I really like and that are my own creations. I once worked
>with a potter in Santa Cruz who was staring from scratch in his glaze
>development. He settled on a base glaze and then mixed tiny amounts and
>set up a grid on a tile with increasing amounts and different kinds of
>add's. We probably had a few hundred glazes with which to begin further
>tests. Of these hundreds we chose about 20 to test further and then from
>those narrowed it down to 5 or 6. He ended up with some stunning glazes.
>Essentially what we had were variation on the same glaze. That is to say
>one base with different add's. I think that I will follow this route as
>well since it is familiar to me. I am, however, interested in other
>theories on this topic. Any ideas?
Paul,
I would try do exactly has you have indicated. Firstly develop a base
glaze that is a clear transparent shiny glaze that does not craze on
your clay bodies.
The next stage that I would suggest is to do a triaxial blend of this
base glaze with additions of opacifiers. Say 5% tin oxide and 10%
titanium dioxide, each triaxial with different % colouring oxides. This
will produce a wide range of colours and finishes. For an example you
can go to my web site and look under Pottery Techniques / Opacifier Test
Series.
http://www.dhpot.demon.co.uk
If you want to do more (the above could produce a few hundred test
tiles), then try modifying your base glaze by line blends with
increasing alumina or the silica or adding barium. Then do line blends
with different colouring oxides on those that look interesting.
Much of the testing for Mike Bailey's book 'Glazes Cone 6' was done as
above and his book is an excellent reference to developing glazes.
Be systematic and keep all your test tiles such that you can readily
refer back to them at any time and look up their recipes.
David
--
David Hewitt
Web:- http://www.dhpot.demon.co.uk
Paul Raymond on wed 19 may 04
firing
Kathryn and Stuart,
Hi. Before I answer your question I am no means an expert. However, I do
have a fair amount of glaze experience. When I lived in Santa Cruz I
helped a potter friend of mine develop his glaze palette. He was a
stickler for sieving.
Briefly, the entire process worked liked this: He started with several
Currie grids, (or something similar, about 4 as I recall). After a base
glaze was decided upon we did color blends on them and chose about 20
from what were probably 200 or so choices. Those 20 were then mixed up
to larger batches, about 1000 grams, I think. While all of this mixing
and weighing was going on we threw a whole lot of small cups, about 2 to
3 inches tall. After everything was mixed we very carefully set up a
process to dip every glaze over AND under every other glaze. Each cup
was coded with a high fire glaze pen so we would know for eternity
exactly which glaze was applied on that cup first and which glaze was
applied over it. The first dip covered the majority of the cup while the
second only covered the top half. That way we could see each glaze
individually as well as in concert with another.
Based on those results we again narrowed down the 20 to six that we
liked the best. By this time my friend, Steve, was throwing his regular
ware.
It is important to realize that Steve was working at his art for several
years before I knew him. By the time that I became acquainted with him
he had many years to develop his vision and he knew exactly what he was
trying to achieve. The reason we did all of the over and under dipping
was that those results were essential to how he ultimately wanted to use
his glazes. He threw very open and broad bowls almost exclusively. In
effect they served as large canvases for an abstract-expressionist
application of glaze. In fact some of these bowls were large and flat
enough that with the aid of a carefully carved foot they could be hung
on a wall. (A wire was wrapped around the foot and a simple loop bent
into it.)
By the time I got into school I had a pretty good idea of one way the
deal with glaze research. This is the model that I base my own work on.
He was a good teacher and since I did not go on to get an MFA this is a
very important foundation for my own work.
So, to answer your question, Yes we sieved. Twice at least. In my own
work I find that the glaze gets a good and thorough mixing by taking the
time to sieve. For one thing it gives you a chance to see all of the
particles in your glaze as they interact with water. This is especially
true when the last little bits of material are being shoved through the
screen. You can see what is too big to make it through. Usually there
are some sand-grain sized "things" that I find interesting to know are
there. I usually just turn over the sieve and include them in the glaze.
It is just a detail that I am glad to know about.
I have never heard of anyone who does not sieve their glazes and in fact
have heard it said that it is a good idea to sieve them before you use
them. Especially if they have been sitting for longer than a few weeks.
I hope this answers some of your questions. Good luck.
Paul Raymond
Franklin, Tennessee
-----Original Message-----
From: Kathryn & Stuart Fields [mailto:sfkf@iwvisp.com]
Sent: Wednesday, May 19, 2004 11:52 AM
To: 'Paul Raymond'
Subject: RE: Been lurking and working now back with some
questions...Glazes and firing
Thank you so much. Yes, it will be lots of use. Setting up a clear
system
of glaze development and testing, especially as a novice, with few
knowledgeable around, has been a difficulty.
In your glaze mixing have you found it very necessary or not, to sieve
glaze
materials. I've read both yes and no and a teacher does not have us do
this
when we're mixing class glazes, so I'm not sure. Is the weighing and
mixing
more even and reliable over different batches when the materials are
sieved?
What has been your experience?
Kathryn Fields
VK Support Services
P. O. Box 1585 / 8075 Seibenthal
Inyokern, CA 93527
(760) 377-4478 ph
(760) 408-9747 cell
www.vkss.com
sfkf@iwvisp.com
-----Original Message-----
From: Paul Raymond [mailto:crazyrays@bellsouth.net]
Sent: Friday, May 14, 2004 3:28 PM
To: 'Kathryn & Stuart Fields'
Subject: FW: Been lurking and working now back with some
questions...Glazes and firing
Hi K and S,
The below message is very informative and perhaps could be of use to
you. Good luck with your glaze work.
Paul
-----Original Message-----
From: David Hewitt [mailto:davidhewitt@dhpot.demon.co.uk]
Sent: Friday, May 14, 2004 1:00 PM
To: Paul Raymond; CLAYART
Subject: Been lurking and working now back with some questions...Glazes
and firing
In message , Paul Raymond writes
>
>And lastly, How do you develop your glazes? My goal is to have about 6
>glazes that I really like and that are my own creations. I once worked
>with a potter in Santa Cruz who was staring from scratch in his glaze
>development. He settled on a base glaze and then mixed tiny amounts and
>set up a grid on a tile with increasing amounts and different kinds of
>add's. We probably had a few hundred glazes with which to begin further
>tests. Of these hundreds we chose about 20 to test further and then
from
>those narrowed it down to 5 or 6. He ended up with some stunning
glazes.
>Essentially what we had were variation on the same glaze. That is to
say
>one base with different add's. I think that I will follow this route as
>well since it is familiar to me. I am, however, interested in other
>theories on this topic. Any ideas?
Paul,
I would try do exactly has you have indicated. Firstly develop a base
glaze that is a clear transparent shiny glaze that does not craze on
your clay bodies.
The next stage that I would suggest is to do a triaxial blend of this
base glaze with additions of opacifiers. Say 5% tin oxide and 10%
titanium dioxide, each triaxial with different % colouring oxides. This
will produce a wide range of colours and finishes. For an example you
can go to my web site and look under Pottery Techniques / Opacifier Test
Series.
http://www.dhpot.demon.co.uk
If you want to do more (the above could produce a few hundred test
tiles), then try modifying your base glaze by line blends with
increasing alumina or the silica or adding barium. Then do line blends
with different colouring oxides on those that look interesting.
Much of the testing for Mike Bailey's book 'Glazes Cone 6' was done as
above and his book is an excellent reference to developing glazes.
Be systematic and keep all your test tiles such that you can readily
refer back to them at any time and look up their recipes.
David
--
David Hewitt
Web:- http://www.dhpot.demon.co.uk
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