Margaret Barlow on thu 19 sep 02
Hi Dawn,
I put your glaze on INSIGHT and thought you might also like the Gerstley
Borate removed as one day you will run out of it.
While I'm not sure of your analysis for GB the following might work for you
as it also reduces the expansion from 520 to 504. Hopefully this will
eliminate crazing.
The revision might not behave as well in the bucket (no GB to flocculate it
and little clay) so you may have to add 1-2 % Bentonite.
Of course you still add the tin and RIO in the same %.
G-200 FELDSPAR G200. 27.50
WHITING............. 7.50
STRONTIUM CARBONATE. 3.50
SILICA.............. 21.50
FRIT 3134........... 27.50
TALC................ 3.50
EPK KAOLIN.......... 9.00
========
100.00
CaO 0.562*10.831%w12.295%m
MnO2 0.000 0.006 0.005
MgO 0.083* 1.147 1.813
K2O 0.098* 3.157 2.135
Na2O 0.184* 3.907 4.013
Fe2O3 0.002 0.122 0.048
TIO2 0.001 0.029 0.023
B2O3 0.283 6.752 6.179
AL2O3 0.257 9.006 5.623
SiO2 3.031 62.420 66.255
P2O5 0.000 0.011 0.005
SrO 0.073* 2.611 1.605
COST/KG 2.211
Si:Al11.782
SiB:Al12.882
EXPAN504.039
MDT: C:\INSIGHT5\RSE01.TMT
If you test this revision, please let me know the results.
thanks............Margaret
> I forgot to put in the recipe for Cream Breaking Red cone 6.
> 41 G200
> 22 Gerstley Borate
> 9 Whiting
> 3 Strontium carb
> 25 Flint
> 13 Tin Oxide
> 2 Red Iron Ox.
>
Margaret Barlow on thu 19 sep 02
Just another observation about this glaze. It is low in Alumina so you
might be better trying to get the colour you want from one of John and Ron's
glazes.
You could probably get the same colour by adding the tin and rutile to one
of their bases but 13% is a lot of tin and not only is it expensive, that
much tin will probably make the glaze less durable. I would try some tests
with less tin and less RIO.
......Margaret
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