Linda Arbuckle on sun 10 dec 00
Been away from ClayArt for some time. I'm back from 7 weeks at
University of Wales Institute Cardiff as a research fellow. I enjoyed
the people, the program (bachelor's, MA, and PhD), and the place very
much. It was a good experience to be outside my own life minutia for a
while to have room to think. UWIC has a strong, lively Ceramics program,
and is located 2 blocks from downtown Cardiff. It was delightful. I
developed a fixation on Jamaican flavor Cornish Pasties. Anyone
interested in info about UWIC should contact Michael Hose, director of
the graduate program:
mhose@uwic.ac.uk
UWIC is part of an international board that launched Interpreting
Ceramics, a refereed journal for ceramics. For those not emeshed in
academia, it's a common practice in many disciplines for creditable
journals to be "refereed"... this means a board of people who know the
discipline read the submissions and agree that the material is valid and
of scholarly interest. So, if you read it someplace like The New England
Journal of Medicine, it's real. In academic circles, art historians are
expected to publish in refereed journals, rather than someplace like
Lady's Home Journal, where you can print anything the editor thinks
entertaining. The perk for the Ceramics field is not only that we have a
new resource for information for articles about our field, but this may
also attract a larger group of knowledgeable writers to Ceramics. I also
suspect that may students interested in Ceramics may have written art
history papers that would be suitable for publication in Interpreting
Ceramics. Check it out:
http://www.uwic.ac.uk/icrc/
The studio research I did there was cone 6 majolica, and majolica w/o
gerstley borate. I was using Morgen Hall's studio at UWIC, which was a
porcelain studio, and was intially reticent to use terracotta in a
porcelain studio. I'm not that tidy. So I used their St. Thomas White
stoneware, and a cone 6 majolica glaze from Richard Burkett (thanks
Richard!). I took my copy of Bob Wilt's GlazChem with me (Thanks, Bob!
http://www.dinoclay.com/), and found the UK frit analysis on Tony
Hansen's Digitalfire web site (Thanks, Tony! http://digitalfire.com/).
Put that on materials cards in GlazChem, and re-calculated. Sorry to say
that I didn't think to bring that recipe home with me, but I can track
it down through people there if I need to. It was a lot of fun to have
such a practical use for glaze calc. Tested a variety of cone 6 glazes
that I knew from home, and they worked fine with UK frits.
Base glaze below. The next problem was to work without gerstley borate.
And there was no CMC gum in shop. Using the frit I based the glaze on, I
found that 1 -1 1/2 frit + colorant (by volume) fluxed decorating
colors pretty well. Add glycerin for better brushing (find this at a
Pharmacy). The issue with this was that it was VERY powdery dry. In the
video from the Gardiner Museum majolica show, the Matthias Ostermann
demo shows him using this powdery surface to blend colors with his
fingers. I found I couldn't wax over the motifs w/o dragging the color
all over. Hairspray will harden the surface nicely, but it also seals it
up, so further work doesn't absorb all that well. An e-mail to Pete
Pinnell saved me. (Thanks, Pete!). He suggested adding bentonite to
harden the surface. Worked well. I ended up using (by volume) 1
bentonite, 1 colorant, 1 to 1 1/2 frit + a bit of glycerin once it was
mixed with water. BUT, you really need to mix the betonite, colorant,
and frit DRY. Bentonite doesn't mix well with water. If you've ever
cooked and tried to mix cinnamon with liquid... it's like that. Mix the
cinnamon with sugar first, and it's much easier.
I eventually went to terracotta and tested the colors + frit + bentonite
+ glycerin at lowfire. The frit fluxed a bit more than g.b., so I could
use 1 -2 1/2 frit with colors. Things that melt well at lowfire
(copper, iron, cobalt) use 1 - 1 1/2 frit. Things that are more
refractory (rutile, chrome, some stains like Vivid Blue Mason stain) go
for the high end. I recommend you test first to adjust the amount of
flux.
Relieved that it works w/o g.b.. I need to test CMC gum, which may solve
brushability and surface hardener in one place.
>From Richard Burkett at San Diego State U, a revised version w/o g.b.
Majolica Midrange cone 5-6
Dolomite 2.3
Whiting 8.7
Feldspar 35.8
EPK 5.8
Flint 35.7
Frit 3124 10.5
plus:
Zircopax 12
Bentonite 2
Epsom salts 0.6
>From Linda Litteral - SDSU Glaze class 1996. She called it 'A-7
Chinese.' Tested for new Midrange majolica for class use. Almost boron
free - good for stain colors that are subject to dissolving in boron
glazes. Very stable, does not move during firing unless quite thick.
Will crawl slightly if very thick. Applies well either by dipping or
brushing.
As they say in the U.K., cheers....
Linda (p.s. I came back just after the elections. I did vote absentee
ballot, and thankfully left before it dragged on to become REALLY
embarassing to not only be from the U.S. but from FL)
--
Linda Arbuckle, Assoc. Prof.
Univ of FL
School of Art and Art History
P.O. Box 115801, Gainesville, FL 32611-5801
(352) 392-0201 x 219
e-mail: arbuck@ufl.edu
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