Ron Roy on mon 22 feb 99
Hi Michelle,
There are a few things out of balance with your glaze so i took the liberty
of reformulating with all the oxides within the limits. This is
theorectical - not tested so do some testing before you star glazing ware
with it.
While I think it's a durable glaze there are things you can do to it that
will not do well under some conditions - like acidic food use. the 4%
copper is not recommended for instance - Vanadium Petoxide shaould not be
used for food bearing surfaces - unless you have the glazes tested. It's
not the kind of oxide I would want to have to be around either.
The expansion is close to your glaze below - if you choose to try this
please report to the list - with the recipe - on how it turns out.
My revision to make a more balanced glaze - RR
-----------------
G 200 SPAR................29.00
Gers Borate 9/97..........6.00
WHITING......................5.00
TALC..............................5.00
F3134..........................25.00
SILICA.........................15.00
EPK..............................15.00
BENTONITE.................2.00
----------
Total........................ 102.00
FORMULA & ANALYSIS
------------------
*CaO........ .55 10.11%
MnO2....... .00 .01%
*MgO........ .15 1.93%
*K2O........ .11 3.35%
*Na2O....... .20 3.98%
Fe2O3...... .01 .27%
TIO2....... .00 .05%
B2O3....... .34 7.84%
AL2O3...... .36 12.07%
SiO2....... 3.07 60.38%
P2O5....... .00 .02%
RATIO 8.50
EXPAN 468.97
WEIGHT 305.07
>----------------------------Original message----------------------------
>Hi all Clay nuts...
> Im just starting out, so forgive the elementary question...I am looking
>to start mixing my own glazes and was given a recipe for ^5-6 oxidation and
>would like some opinions/suggestions on it and possibly get other base glaze
>formulations.....
>Nepheline Syenite 47.3
>Colemanite 27.0
>Flint 20.3
>Kaolin (EPK) 5.4
>Bentonite 2
>for colors use
> Green-4% Copper Carbonate
> Brown-5% Iron Oxide, 5% Tin Oxide
> Turquoise-5% Tin Oxide, 2% Copper Carbonate
> White-6% Tin Oxide
> Blue-1/4% Cobalt Oxide, 5% Tin Oxide
> Creamy Yellow-5% Tin Oxide, 5% Vanadium Pentoxide
> Olive Green-5% Tin Oxide, 3% Vanadium Pentoxide, 3% Copper Carbonate
>
>Thanks in advance...
> Michelle H.
Ron Roy
93 Pegasus Trail
Scarborough, Ontario
Canada M1G 3N8
Tel: 416-439-2621
Fax: 416-438-7849
Web page: http://digitalfire.com/education/people/ronroy.htm
| |
|
