Diane Woloshyn on mon 14 feb 00
Hi Ron,
Got the results from Alfred on two glazes I had tested. The first was the
Saffire Blue (RRA10/99) that you reformulated for me and the second was one
sent to Clayart by Gus Morcate called Stonehenge.
Saffire Blue RRA10/99
Frit 3134 37
EPK 26
Flint 17
Strontium Carb 4
Custer feldspar 16
Rutile 4.5
Cobalt Carb 2.5
Cobalt tested <0.05 MG/L which is less than detectable limits.
Once again great job, Ron, and a great glaze. This needs to be applied
heavily and will run if not fettled well.
Stonehenge
Flint 56
Whiting l88
Soda feldspar 516
Kaolin EPK 154
Zinc Oxide 86
Rutile 40
Cobalt carb 10
Ilmenite gran 30
(add after seiving)
Cobalt 0.317 MG/L This seems pretty high to me and I wouldn't use it on
anything that might be subject to food leaching. It is a very pretty glaze
on both light and dark clay. Just a further note, I tested this the first
time on a 200mg batch and then mixed up a 1000 gm batch. When I converted
the glaze to the larger amount I put a decimal in the wrong place and used
only 10% a of the colorants needed. (Rutile, cobalt and ilmenite) This also
turned out to be very pretty mottled baby blue matt.
Don't have a report yet on the mysterious glaze precipitate, but the tests
are sitting in the refrigerator now.
Thanks again for your help and I hope this furthers the glaze knowledge base a
little bit.
Diane Florida Bird Lady
Phyliss Ward on tue 15 feb 00
What cone are these glazes?
Diane Woloshyn wrote:
> ----------------------------Original message----------------------------
> Hi Ron,
>
> Got the results from Alfred on two glazes I had tested. The first was the
> Saffire Blue (RRA10/99) that you reformulated for me and the second was one
> sent to Clayart by Gus Morcate called Stonehenge.
>
> Saffire Blue RRA10/99
>
> Frit 3134 37
> EPK 26
> Flint 17
> Strontium Carb 4
> Custer feldspar 16
> Rutile 4.5
> Cobalt Carb 2.5
>
> Cobalt tested <0.05 MG/L which is less than detectable limits.
> Once again great job, Ron, and a great glaze. This needs to be applied
> heavily and will run if not fettled well.
>
> Stonehenge
>
> Flint 56
> Whiting l88
> Soda feldspar 516
> Kaolin EPK 154
> Zinc Oxide 86
> Rutile 40
> Cobalt carb 10
> Ilmenite gran 30
> (add after seiving)
>
> Cobalt 0.317 MG/L This seems pretty high to me and I wouldn't use it on
> anything that might be subject to food leaching. It is a very pretty glaze
> on both light and dark clay. Just a further note, I tested this the first
> time on a 200mg batch and then mixed up a 1000 gm batch. When I converted
> the glaze to the larger amount I put a decimal in the wrong place and used
> only 10% a of the colorants needed. (Rutile, cobalt and ilmenite) This also
> turned out to be very pretty mottled baby blue matt.
>
> Don't have a report yet on the mysterious glaze precipitate, but the tests
> are sitting in the refrigerator now.
>
> Thanks again for your help and I hope this furthers the glaze knowledge base a
> little bit.
>
> Diane Florida Bird Lady
--
Phyliss
pward@lightspeed.net
http://www.bodywise.com/consultants/bpward
iandol on thu 17 apr 03
Dear Jim Murphy,
Thanks for that imput. The idea of MgO from the ash precipitating as a =
Pyroxene had not occurred to me, but it is a good point to ponder. =
Certainly the idea of P2O5 had for the blue effect had come to mind.
I have started doing the calcs for the No 1 tile of the =
K-Feld-Kaolin-Silica-Wollastonite series. No 1 with ~71.4% K-Feld, ~3.6 =
Quartz, ~17.9 Woll and ~7.1 Kaolin is a transparent uncrazed glaze =
opacified with fine bubble inclusions with a slight weak pale green =
tinge . Unity formula gives 3.56 SiO2, 0.53 Al2O3, 0.53 CaO, 0.34 K2O, =
O.10 Na2O, 0.01 MgO with 0.01 TiO2 and 0.01 FeO. Calculated with the =
Hogg Program. Good enough ball park figures for the 3D plot I will be =
doing.
Best regards,
Ivor.=20
Ann Griffin on sun 29 jun 08
Hi Glazemakers,
I have been testing a glaze on red and white clays, and have noticed a
difference in the results in the surface texture between red and white
clays even with the same batches of glaze, dipped at the same time.
I'm wondering if the iron in the red glaze would make the glaze
glossier on the red clay. The glazes come out much more matte on the
white clay.
The recipe is as follows
^03 electric w/ox
Gerstley Borate 38
Silica 42
Lithium Carb 10
Neph sy 5
EPK 5
====================
100
I'm adding 7% tin oxide as an opacifier
I'm wondering if adding a small (negligible) amount of an iron oxide
to my recipe could make the glaze a little glossier on the white clay,
or would it change the color just by being there? The recipe is meant
to be semi-gloss or semi-matte, but i like the slight bit more gloss
that the red clay gets - Is there a better way to do this?
By the way, it doesn't seem to matter which colorants I use - they all
show the same differences in surface texture between the red and white
clay.
thanks in advance
Ann Griffin
Cathi Newlin on fri 6 aug 10
I spent the last couple days getting a load of test tiles ready and got
them fired yesterday, with a mix of results.
It was by far my most methodical and organized attempt and glaze testing.
If you're into such things, I have the results up on my blog:
http://squarepegarts.blogspot.com/2010/08/16-glazes-80-test-tiles.html
Have a great weekend all!
--
Cathi Newlin, Angels Camp, Ca
cathi@box49.com
box49@caltel.com
cathi@SquarePegArts.com
-------------------------------
The Square Peg
http://www.squarepegarts.com
California Boxers in Need:
http://CaliforniaBoxer.org
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