Carol Durnford on tue 28 oct 97
It's been a long time coming but here are some experimental tests.
I've tagged on the glaze recipes at the end of this letter.
Thanks Susan Maguire sor submitting in october of last year, Ralph for
asking, and Rick Shay for creating. ( I hope that is right )
In preparing these glazes I did the following because they settle so
badly. I also found this true of Lana Wilson's unstable Chartreuse Moss and
red moss glazes which I was testing at about the same time. I started with
1,000 gram batches, but several dried out in their open containers before I
got around to using them so I reconstituted them with the water and put them
in a blender along with enough CMC to keep them suspended. (When I use CMC
I take a given amount of water and gradually add CMC powder to it till it
won't take any more. If there are lumps, I simply leave it for a day or
two, shake it occasionally and eventually all of it dissolves and disperses.
One drop of iodine keeps it from rotting as it is an organic suspending
agent. I keep small glaze batches and such things like CMC solution in
those Ocean Spray plastic gallon juice jugs. They work great, easy to shake,
glaze then bake).
I concentrated my efforts on the lizzard and the lichen glazes since
I didn't really care that much for the others on my clay body, and I was
looking for textures. My clay body was a fireclay based paperclay with a
perlite filler. I dumped the glazes that I didn't use into a single
container and used them in combination with oxide washes and got lots of
variation in surface colors. One like rich iron rust from iron oxide with a
bluegreen copper patina. For my test tiles I would make long flat strips of
clay and put bands of underglaze across the surface and then run a double
coating of lichen glaze down 1/2 the length and then the lizzzard glaze down
the other half. This made for some interesting transitions areas between
the underglazes.
Lizzard>|-------|-------|-------|-------------|
| UG | UG | UG |
==========================================
| | | |
Lichen>|-------|-------|-------|---------------
Lana Wilson's chartreuse and red moss glazes can be found in the
Summer issue of ceramics monthly 1995. Lana's red moss tests worked fine
but I never could get the Chartreuse Moss to be chartreuseeeeee. I noticed
that the Charteuse moss was a very very bright yellow on my high iron slips,
so I started using various underglazes to alter the color and guess what????
results. While using Duncan's cobalt crystal black underglaze, I got the
most beautiful combinations of varying shades of fluorescent green,
including a chartreuse color. Looked like green velvet. Since I've been
making ceramic pillows, this was really appropriate. So I extended this
practice to the lizzard and lichen glazes. I found that the glazes would
pickup the underglaze colors and/or the edges would peel upward to reveal
the brighter underglaze colors and in the case of the lichen glaze would
impart a richer bluish texture to the pieces. Different results were
obtained with different underglazes. Sometimes the Reward Velvets would
work better with the Lizzard glaze than the Lichen. It was very exciting.
So, I did my preliminary thesis exhibition using low-fire
glaze/underglaze/oxide wash combinations on my sculptures. I had never
worked with low fire glazes and it was quite a trial but there were some
successes.
Refirings were usually unsuccessful except with the Lichen glaze.
The lizzard glaze would just lay flat with no texture. After about the
third or fourth firing the lizzard glaze would look like green acrylic
paint. YUK,,cough, cough, cough.... OK< if you're making little green
dragons it would work just fine.> This also happened when the glazes were
fired to cone 04. I would suggest firing to cone 05 or preferably cone 06
which created the best textured surfaces for me.
I just thought some of you low fire pyro's might enjoy my playtime in
low fire glazes. I understand that these glazes have been around for a long
time --- 10 to 15 years.. Another local potter recognized them and actually
had the recipes, but never used them.
Glazes are in weights of measure, for example: grams
Lichen glaze
50 Magnesium Carbonate
10 Lithium Carbonate
50 Borax
30 Gerstley Borate
4 Copper Carbonate
.4 Cobalt Carbonate
Lizard:
40 Magnesium Carb.
15 Lithium Carb.
10 Borax
70 Gerstley Borate
5 Silica
30 Neph Syenite
.4 Chrome Oxide
Craters:
20 Magnesium Carb
20 Kaolin
60 Lithium Carbonate
30 Borax
12 Copper Carb.
60 Silica
10 Bentonite
Earthmother:
30 Lithium Carb.
30 Gerstley Borate
3 Copper Carb
20 Silica
1 Cobalt Carb
10 Ball Clay
10 Talc
3 Manganese dioxide
Ocean Oil:
10 Kaolin
30 Lithium Carb.
20 Broax
40 Gerstley Borate
6 Copper Carb
40 Whiting
Superstition:
30 Lithium Carb.
40 Gerstley Borate
3 Copper Carb.
.5 Cobalt Oxide
30 Talc
40 Whiting
Beads:
50 Magnesium Carb.
40 Borax
50 Gerstley Borate
10 Silica
10 Zircopax
I found this to be rather rough in texture and not the smooth beads
I was expecting.
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