Marcia Selsor on fri 9 mar 07
I did my masters thesis on crystalline glazes back in 1973. During an
early firing of my own new electric kiln, I had a crystalline glaze
pot fall off the catch bowl and eat a 2 inch hole in the floor of my
new kiln. I was able to patch it by chiseling all glaze out of the
brick and filling it with new brick and kiln cement. Having spent 25
years as a ceramics prof on a limited operating budget, I empathize
with the powers that be.
Crystalline glazes have a fantastic history from the Arts and Crafts
era in this country. I read many lab reports from the Ceramics
engineering school at Univ. of Ill.
and even studied hand written kiln firing notes from 1903.
Lots of interesting info.
But if it isn't your kiln, I think you should hold off. You could
easily cause a lot of damage.
The glazes need to be runny in order to "freeze" them and form
crystals and they are costic and eat brick.
For a catch basin I used a soft brick cut to fit the base of a ^10
bisqued pot and put both in a high temp bisqued bowl. The brick was
covered with high alumina kiln wash. Glaze with gum arabic was
applied to the ^10 bisqued pieces. This worked. But it is important
to bisque high so there is no movement on the catch basin during the
Try researching some earlier information. Taxile Doat (Grand Feu
Ceramics),and Adelaide Robineau, plus the entire crew at Univ. of
Ill. in 1903.
William & Susan Schran User on fri 9 mar 07
On 3/9/07 5:42 PM, "Stephanie Wright" wrote:
> Hi Bill and Everybody!
> I have been reading the book "Crystalline Glazes" by Diane Creber, and am
> absolutely fascinated by the crystalline glaze process! I would love to
> try it, but the powers that be at my pottery class are hesitant to let me.
> I may be able to convince them if there is any way to decrease the
> runniness of the glaze while still getting crystal formation.
> There are two potters noted in Ms. Creber's book. They are Raymond Phaneuf
> (pg 44), and William Sawhill (pgs 114-115). The photo of Mr. Phaneuf's pot
> has the notation that he puts a non-flowing glaze on the bottom of the pot
> to reduce running of the crystalline glaze. A description of Mr. Sawhill's
> work says that he layers 3 different glazes on his pots to reduce running -
> a "colourant" glaze, a crystalline base, and a "barrier layer" glaze.
> Have you tried, or are you familiar with either of these methods? The book
> did not go into any detail regarding how much this helped slow/stop the
> glazes from running.
Yes, I have done these processes. If you will go to my web site (URL after
my signature) and go to "galleries>selection of my work", the top row shows
some of my crystalline glazes - the two on the right have a crystalline
glaze on the top portion and a ^6 glaze on the bottom.
> Do you think either of these methods would eliminate the need for grinding
> the foot of the pot? I don't mind using collectors under the pots while
> firing, but my school does not have the tools necessary for grinding.
You'll still want to use a glaze catcher & some type of pedestal. The
pedestal mix I use that is shown in my "lattice structures" presentation
should work fine.
> Is there any other way you know of to stiffen a crystalline glaze a bit
> without sacrificing crystal formation?
Yes, but it does take much experimentation. William Melstrom does this & raw
glazes his pots. He doesn't use pedestals or catchers, but he's been doing
it many years. You can check his web site: http://www.handspiral.com/
> Also, has anyone found a way to fire crystalline glazes successfully in a
> reduction atmosphere? I mean, besides firing in oxidation then refiring in
> reduction, or just barely reducing at the very end of the firing?
There are crystalline artisans doing this in a special gas fired kiln built
by Geil Kilns. It has a programmable controller that controls the firing and
the atmosphere in the kiln - oxidation going up, then reduction during
certain cooling stages.
Good luck, Bill
William "Bill" Schran
William & Susan Schran User on sat 10 mar 07
On 3/9/07 9:15 PM, "Marcia Selsor" wrote:
> For a catch basin I used a soft brick cut to fit the base of a ^10
> bisqued pot and put both in a high temp bisqued bowl. The brick was
> covered with high alumina kiln wash.
I didn't start the "crystalline madness" until a few years after Marcia.
In 1977 I saw a ceramic exhibition in Columbia, Maryland from the collection
of several people. Two pots were crystalline glazed porcelain by Herbert
Sanders. Right then & there I knew a just had to find out more. Sanders had
just come out with his book "Glazes for Special Effects". He showed the
process of cutting IFB to form pedestals for crystalline glazed pots.
After having many bricks melt from the glaze flow, I slowly moved away from
A December 1975 article in CM by David Snair illustrated the technique of
creating pedestals with the same clay from which the pot was made. I used
this technique years later when I revisited this glazing process.
It wasn't until 1990 that some of my students started asking about the
crystalline glaze technique that I began thinking about it again. After a
few firings, it became clear that our kilns were not up to the task of ^10
crystalline firings. I went about a couple years research to see if one
could produce crystalline glazes at ^6. Several experiments were promising
and I passed the information along to my students.
I now work with crystalline glazes at ^6 and experiment and test on a
continuous basis. My website contains much of the information about my
process that I continue to perfect. I figure there are many folks out there
that are fascinated by crystalline glazes, but have kilns that can't go to
^10 or don't wish to take the kiln to it's limit. The process I'm working
with will make the magic of crystalline glazes accessible to more potters.
William "Bill" Schran
Marcia Selsor on sun 11 mar 07
I sat in a collector's living room in Chicago and she showed me some
Natzler's crystalline glazed pots. They are
unbelieveable. Unlike any macro crystal I have ever seen. Long curly
cues. That is what intriqued me to reserach crystalline glazes.
Interesting how the real live work can move you!
On Mar 10, 2007, at 8:40 AM, William & Susan Schran User wrote:
> I didn't start the "crystalline madness" until a few years after
> In 1977 I saw a ceramic exhibition in Columbia, Maryland from the
> of several people. Two pots were crystalline glazed porcelain by
> Sanders. Right then & there I knew a just had to find out more.
> Sanders had
> just come out with his book "Glazes for Special Effects". He showed
> process of cutting IFB to form pedestals for crystalline glazed pots.
> After having many bricks melt from the glaze flow, I slowly moved
> away from
> the process.
> William "Bill" Schran