Mary Ella Yamashita on sat 18 sep 99
I have glaze fired a lidded jar to ^6. The glazed part looks fantastic,
but I painted the knob with a black mason stain, no glaze, and it looks
unfinished. I am considering refiring around ^06 with a clear glaze over
the stain. My concern is how the refiring would affect the glazed portion
of the piece. I am including the recipe for the glaze, which is a
variation of Ron Roy's ^6 Black #2. I would appreciate any insight anyone
might have (would I possibly be better off just painting some acrylic or
varnish over the knob instead of trying to refire? The jar is a funerary
urn for a cat.) TIA--Mary Ella
Here is the glaze recipe:
SHOYU BROWN ^6
Surface: Glossy
Firing Type: Oxidation
Color: Dark Brown when thick, mottled dark brown when thin
Ferro Frit 3134 26.00
Custer Feldspar 27.00
Wollastonite 11.00
Talc 4.00
Epk 15.00
Flint ( Silica ) 17.00
Red Iron Oxide (ferric) 9.00
Cobalt Carbonate 1.00
Estimated Thermal Expansion = 63.6 x 10^-7 / degree C
Silica:Alumina Ratio = 10.21:1
Unity Molecular Formula:
0.092 K2O 0.325 Al2O3 3.320 SiO2
0.182 Na2O 0.276 B2O3
0.594 CaO 0.182 Fe2O3
0.027 CoO
0.105 MgO
Percentage Analysis:
2.47 % K2O 9.44 % Al2O3 56.73 % SiO2
3.20 % Na2O 5.46 % B2O3
9.48 % CaO 8.25 % Fe2O3
0.57 % CoO
1.20 % MgO
Barney Adams on sat 18 sep 99
Hi
I have refired a few of my work in my bisque load. I bisque to ^04.
I do this with Chris's red and the red comes out much stronger. However
on pieces with the red and Ron Roy's Black the black goes gray. You may
want to test.
Barney
Mary Ella Yamashita wrote:
> ----------------------------Original message----------------------------
> I have glaze fired a lidded jar to ^6. The glazed part looks fantastic,
> but I painted the knob with a black mason stain, no glaze, and it looks
> unfinished. I am considering refiring around ^06 with a clear glaze over
> the stain. My concern is how the refiring would affect the glazed portion
> of the piece. I am including the recipe for the glaze, which is a
> variation of Ron Roy's ^6 Black #2. I would appreciate any insight anyone
> might have (would I possibly be better off just painting some acrylic or
> varnish over the knob instead of trying to refire? The jar is a funerary
> urn for a cat.) TIA--Mary Ella
>
> Here is the glaze recipe:
>
> SHOYU BROWN ^6
> Surface: Glossy
> Firing Type: Oxidation
> Color: Dark Brown when thick, mottled dark brown when thin
>
> Ferro Frit 3134 26.00
> Custer Feldspar 27.00
> Wollastonite 11.00
> Talc 4.00
> Epk 15.00
> Flint ( Silica ) 17.00
> Red Iron Oxide (ferric) 9.00
> Cobalt Carbonate 1.00
>
> Estimated Thermal Expansion = 63.6 x 10^-7 / degree C
> Silica:Alumina Ratio = 10.21:1
>
> Unity Molecular Formula:
>
> 0.092 K2O 0.325 Al2O3 3.320 SiO2
> 0.182 Na2O 0.276 B2O3
> 0.594 CaO 0.182 Fe2O3
> 0.027 CoO
> 0.105 MgO
>
> Percentage Analysis:
>
> 2.47 % K2O 9.44 % Al2O3 56.73 % SiO2
> 3.20 % Na2O 5.46 % B2O3
> 9.48 % CaO 8.25 % Fe2O3
> 0.57 % CoO
> 1.20 % MgO
Cindy Strnad, Earthen Vessels Pottery on sun 19 sep 99
Mary Ella,
I suppose the advisability of painting/vs glazing the knob depends upon how
frequently the pot will be opened. If your customer plans to open the jar
often, the paint may wear off. If, however, the urn is going into a vault or
into the ground, it likely won't matter much.
Seriously, though, refiring to lower temperatures affects some glazes and
not others. Maybe you have another, less vital piece to experiment on? If
you do refire, do both the lid and the pot.
For future reference, mix your black mason stain with a bit of frit and some
glycerin if you want to leave it uncovered. This still doesn't give a smooth
finish (unless you use a *lot* of frit), but it does afford a more finished
look. The glycerin facilitates brush painting.
Cindy Strnad
Earthen Vessels Pottery
Custer, SD
Bobbi Bassett on sun 19 sep 99
In a message dated 9/18/99 4:45:06 PM Eastern Daylight Time, mey@cswnet.com
writes:
> ----------------------------Original message----------------------------
> I have glaze fired a lidded jar to ^6. The glazed part looks fantastic,
> but I painted the knob with a black mason stain, no glaze, and it looks
> unfinished. I am considering refiring around ^06 with a clear glaze over
> the stain. My concern is how the refiring would affect the glazed portion
> of the piece.
The last time I tried that the glazed portion came out all cratered. I
assumed that the temperature was too low to allow the glazed part to smooth
out again. This from a novice in refiring.....................
Bobbi in PA
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