Paul \"Standing Bear\" on sun 12 dec 99
Hey Clayarters, Happy Holidays.
Looking for a new COBALT BLUE. The one that I have been using is semi
translucent. I am in search of one that is opaque with a high gloss.
Should be for cone 10 reduction. I remember a year or so ago there was some
talk of Noxzema Blue. Open for ideas.
Have a Great Holiday ( I will be glad when it is over).
Paul
innervisionearthart.com
John & Anne Worner on mon 13 dec 99
Hi Paul,
Here is a deep blue/glossy that I have been playing with.
I have not had it tested for leaching of cobalt - yet - but
it does not craze on the claybodies I use: B-Mix, Dillo,
or Armadillo Porcelain.
It breaks nicely over carved areas.
I use the version with cobalt carbonate.
RR - any comments are as usual welcome :-)
Anne
AW DEEP BLUE - ^8-10 - glossy - OX or RX
CUSTER FELDSPAR..... 28.04 28.04%
FLINT............... 26.17 26.17%
WOLLASTONITE........ 22.43 22.43%
EPK................. 18.69 18.69%
GERSTLEY BORATE..... 3.74 3.74%
BENTONITE........... 0.93 0.93%
========
100.00
CaO 0.80* 12.89%
MgO 0.01* 0.11%
K2O 0.12* 3.11%
Na2O 0.07* 1.23%
TiO2 0.00 0.09%
Al2O3 0.44 12.91%
B2O3 0.10 2.04%
P2O5 0.00 0.05%
SiO2 3.91 67.21%
Fe2O3 0.01 0.34%
MnO 0.00* 0.02%
Cost/kg 0.88
Si:Al 8.83
SiB:Al 9.07
Expan 6.70
Notes:
Cobalt Carb: 1%
Black Nickel OX: 1%
Tin Oxide 1%
OR:
Cobalt Carbonate: 2%
Does not shift at ^10.
Paul \"Standing Bear\" wrote:
> ----------------------------Original message----------------------------
> Hey Clayarters, Happy Holidays.
> Looking for a new COBALT BLUE. The one that I have been using is semi
> translucent. I am in search of one that is opaque with a high gloss.
> Should be for cone 10 reduction. I remember a year or so ago there was some
> talk of Noxzema Blue. Open for ideas.
>
> Have a Great Holiday ( I will be glad when it is over).
>
> Paul
> innervisionearthart.com
Dr.Tom Roess on mon 13 dec 99
------------------
Hi Paul, If you want a really blue blue, here it is.
COBALT BLUE Cone 10 Reduction Very blue
Dolomite 2.5
Whiting 18.5
Custer 36
EPK 12
Flint 31
100
Cobalt Carb 2.5 =25
I have not personally tried this recipe, but the description sounds good. =
=22It
is a beautiful deep cobalt blue on porcelain breaking into green along the =
rim
and turns a mottled blue and green on red clays=22.
Glaze Name: Bleu texture cone: 8 - 9 - 10 Reduction
color: Blue textured surface:Semi-gloss
Custer spar 40.83
Whiting 16.97
Strontium carbonate 5.30
EPK 20.89
Flint 16.01
Totals: 100.00 =25
Also add:
Rutile 4.77
Cobalt carbonate 2.55
And finally
,
LAPIS BLUE Cone 10 Reduction
Potash Spar 40
Whiting 25
Cornwall 20
EPK 15
100
Cobalt Carb - 2=25
Bentonite 2=25
Lapis blue -matt surface - no opoacifier, but it doesn't seem to need one.
Must be applied thinly or it's just too blue. This one I have tried and it's
such a strong blue I have mixed it 50-50 with Leach White and it's still =
very
blue.
Good luck,
Lou in Snowmass
Gail Turton on thu 16 dec 99
I just tested the Lapis Blue in two different oxidation firings, and it came
out very nice, VERY blue, on Armadillo Grolleg porcelain. First firing was
to ^9 in my older small Paragon, and the next firing was in my "disaster"
overfiring this week. The glaze held up well at ^10-11, the porcelain did
pretty well too, but the shelves were cracked and bowed beyond belief.
Anyway, this glaze is very strong, even sprayed on lightly, but I give it my
vote...I happen to like blue!
Gail
madwa on fri 17 dec 99
Hi Paul "Standing Bear"
I noticed your email a while back, have been extremely busy, and now notice
you have already found and tried a new Cone 10 Blue, reduction. Good on ya!
Here's another:
Cone 10 Blue Glossy, Reduction
Potash Feldspar 24.39 (I used UK Potash Feldspar)
China Clay 18.70 (I guess you would use EPK)
Gerstley Borate 16.26
Dolomite 12.20
Silica 28.46
Add 4% cobalt carbonate (or 2% cobalt oxide)
My notes on testing this glaze: Very shiny, clear, stable. No cracks to
the naked eye. Pleasing.
The test tile was frozen for 24 hours, then put into a tub of boiling water,
to test for cracks. This was done 3 times in a row, with no cracks. It
works from cone 9 - 11, as far as I've tested, on stoneware and high fire
white stoneware.
I'm a student at the Otago Polytechnic School of Art, going into my 3rd
year, Ceramics. The strength of our school is strong knowledge of all clay
processes and in particular, glaze chemistry. We had to individually come
up with a clear glaze, reduction cone 10. Here's mine. I've done line
blends with various oxides, in oxidation and reduction. Marvellous results.
So, if your kiln oxidises when you don't mean it to, this will work anyway
for your blue. Have fun, do try it and let me know how it goes for you.
Sharry Madden
>From Sweet New Zealand
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