Tuesday, December 11, 2012

Katelyn's Cone 10 Reduction Crystalline Glaze

Tile # 65 Recipe: Cone 10 Reduction
50 Frit 3110
25 Zinc
25 Silica        
2 Red iron
2 Cobalt

Glaze was poured and is fairly thick and glossy glass near the bottom but started to bubble with thinner application, so desired effect might change with different application. The top picture was a range of different frits used with the same silica zinc ratio. I found frit 3110 to respond the best with no blistering or pin-holing. Cobalt comes out dark blue at 2% cobalt and crystals formed are a light blue. This was never applied to a larger surface so I would imagine with the larger surface more crystals would form.

Friday, December 16, 2011

Dameon's Brilliant Blue

Cone 6
Soda  ash            8.9
Ferro frit 3134    8.0
Neph  Sy            37.5
lithium carb         2.4
Strontium car.     17.7
EPK                   20.8
Flint                    4.7

Copper Carb       3%
Cobalt   Carb      .2%

This cone six oxidation glaze is a semi-opaque blue with hints of green throughout its body. Pin-sized blue crystals can be seen on its surface and it breaks clear over texture, leaving depressions a dark, near-green. Use caution when applying this glaze, it tends to run when applied too thick. A thin coat still leaves great results in color. Clay body doesn't seen to have much affect on coloration. Aside from a little running, there are no visible flaws. The glaze has a nice fit without any crazing, however textures can be left sharp if they have an edge already. Fire to cone 6  and enjoy.

Dameon's Opal Blue

Opal Blue
cone 10
Neph sy    35.57
Dolomite   17.13
Zinc oxide  2.49
Whiting      3.12
Kaolin        5.92
Flint            35.77

Rutile         5.01

This glaze is a terrific blue with white crystal lines on white clay and a blue green on high iron clay bodies. It broke on textures, turning thin areas a rusty orange. Applied thick, it ran slightly but was pretty stable. The rutile caused a heavy amount of action on the surface, turning almost white, with faint purple lines where pooling was heaviest. Minimal flaws with this glaze, no pock marking or crazing. However, use caution when applying, Running could be a problem where glaze is applied too close to the foot. Fire to cone 10 in a reduction for best results

Thursday, December 15, 2011

Natalie's Cone 10 Reduction Glaze

Kona F-4 Feldspar         47.0
Dolomite                        19.0
Whiting                            4.0               +                Copper Carbonate         3.0
EPK                                 9.0                                 Tin Oxide                      2.0
English Grolleg              10.0
Flint                                11.0

This is a cool pearly pink and lavender glaze. I'm a purple fanatic so I was pleased to see this tile come out of the kiln.  I think it compliments the clay body nicely, too.  Breaks along the edges to reveal the clay color. This glaze was applied pretty thickly to the tile. If not applied thickly, it seems it would appear more gray and dull in color.  The color is a more deep magenta on the textured side of the tile.
Natalie's Cone 6 Oxidation glaze

Whiting                        9.5
Zinc Oxide                   5.5
Frit 3124                     35.0                   +        Rutile              15.0
Custer Feldspar           20.0                             Vanadium       10.0
Silica                           17.5                            
Bentonite                      7.5
EPK                              5.0

This is light pink colored glaze with nice opalescence, especially where applied thinly.  It's more opaque where applied thicker.  Has a cool "mossy" pattern to it, and breaks nicely along edges.

Wednesday, December 14, 2011

Michelle's Strawberry Rust Δ6

Michelle's Strawberry Rust Δ6
            Whiting                       9.5%
            Zinc ox                        5.5%
            Ferro Frit 3124            44.5%
            Custer Feld                 20%
            Bentonite                    7.5%
            EPK                            5%
            Silica                           8%
Tin Ox                         9%
Red Iron ox                 3%
Ambrosia mason stain 5%
Semi-gloss glaze with dark speckles from red iron oxide and ambrosia orange blushes. Applied on tile by half dipping (on bottom) and half brushing (on top). Fired in oxidation. Good stability. 
(glaze without Red Iron Oxide)

Michelle’s Mottled Lavender Satin Δ10

Michelle’s Mottled Lavender Satin Δ10
            Kona F-4                     47%
            Dolomite                     19%
            Whiting                       4%
            EPK                              9%
            English Grolleg           10%
            Flint                             11%

Glaze was poured into the internal of the bowl where it made a thick pool at the bottom (gathering tiny speckles of teal, burgundy, and white) and on the external was applied with a paint brush in two thick coats, resulting in a striped pattern. Where the glaze was thicker, more white speckles accumulate and where thinly applied, a silky, semi-transparent light purple.  No pin holing or crawling, good stability unless applied too thickly, slips thin over breaks in surface and collects more thickly say below the bowl’s lip. On test tile, over firing occurred and resulted in murky grayish greens (like dull pond scum), the color being somewhat clouded.

Josh's Cone 6 Turquoise Matt

Ball Clay 6
Dolomite 18
Gerstley Borate 22
Spodumene 36
Tin Oxide 8
Zircopax 10
Copper Carbonate 1
Vanadium 5

This cone 6 glaze is a light green to turquoise in color. It breaks brown on raised areas. Overall it seems pretty stable and it is a good glaze to mess around with by adding different colorants. It looks good on white clay or the brown stoneware.

Miriam's Cone 10 Glaze: a variation on Val Cushing's Wild Wonder

Gerstley Borate         48
Talc                    22
Titanium Dioxide        14
Zinc Oxide              10
Lithium Carbonate       6
Black Copper Oxide      2

To make the glaze on this tile, I added 2% black copper oxide to a recipe from Val Cushing’s Handbook.  Cushing recommends this glaze for reduction firings, but after testing it with a variety of colorants, I found all of the results more interesting in oxidation.  The gerstley borate and titanium dioxide in this glaze give it a highly active surface, with streaks of pink and cream.  The addition of black copper oxide gives it a bit of a metallic sheen, and adds greens and grays.  This glaze is quite runny, but it can be stabilized by reducing the gerstley borate to 43% and adding 5% silica.  This will make the glaze less drippy, but will also result in a slight loss of texture.

Miriam's Cone 6 Glaze: a variation on Lana Wilson's Textured Crawl

Nepheline Syenite       60
Magnesium               22
EPK                     18

This recipe is very similar to the original; I just replaced the ball clay with kaolin.  This seemed to make the glaze adhere more smoothly to the tile, and also gave it a pearlescent sheen.  The high amount of magnesium in this glaze is what causes the crawling effect.  It needs to be applied thickly in order to get a good amount of crawl – I applied it about 1/8 inch thick.  It can give interesting results layered over slips and glazes, as long as the base glaze is fairly dry.

Jennifer's Test of Wild Wonder Cone 10

Wild Wonder Base:

Grestly Borate        48
Talc                       22
Titanium               14
Zinc Oxide             10
Lithium Carb           6

+1% Red Iron Oxide

This glaze has some gloss, but is mostly matte. The overall surface of the glaze is inconsistent, there is lots of visual texture within the glaze. It has does have a consistent coloring of reddish brown, even with different colorants added. The colorant seems to separate and run, pooling more towards the bottom. The iron oxide gives a red brown color with spots of green. This is a fairly unstable glaze, definitely for the adventurous.

Jennifer's Translucent Cone 6

Base Glaze:

Neph Sy        44
Zinc Oxide    13
Whiting         7
EPK               8
Flint             28

+6% Rutile
+4% Copper Carbonate

This is a glossy, opaque glaze if applied thick. It has a nice surface, smooth with no bubbles or crazing. Rutile adds a fair amount of visual texture within the glaze. Rutile alone has a nice texture and great color of pink to brown. When mixed with copper carbonate, it makes a nice green glassy glaze with fine texture of brown/pink. This glaze is fairly predictable.

Jim’s Mottled Maroon and Rust Brown Cone 6 Oxidation

Jim’s Mottled Maroon and Rust Brown Cone 6 Oxidation

Ball Clay                               6
Dolomite                             18
Gerstley Borate                   22
Spodumene                         36
Tin Oxide                              8
Zircopax                              10

Add 4 % Iron Oxide

Fired to cone 6 in oxidation, this recipe produces a glossy, semi-opaque glaze. The glaze gives a rich rust brown over white slip and a maroon brown over the plain stoneware. A depth of mottling is exhibited due to the strong action of the primary flux, spodumene. There is good, consistent coverage and no pin holes. The underlying texture on the clay body remains evident with subtle highlights breaking over line patterns and dark valleys on the horizontal line textures. The Unity Molecular Formula (UMF) for this glaze yields a Alumina to Silicon Dioxide ratio of 1:4.

Jim’s Mottled Brown Cone 6 Ramped Up to a Cone 10

Ball Clay                                2.5
Dolomite                             30.3
Spodumene                         30.3
Tin Oxide                             3.3
Zircopax                               4.2
Flint                                     29.4

Add 4% Iron Oxide

This glaze recipe was the result of revising the cone 6 recipe in the blog above to a cone 10 recipe fired in reduction. The UMF was employed to  guide the glaze limit formula and alumina to silica ratio. The first step was to remove the Gerstley Borate. The boron in the Gerstley complicates the UMF, has a low melting range, acts as a glass former, and is an additional flux. Flint was added to bring the Al:Si ratio up to 1:7. The resulting glaze is an opaque, glossy, caramel color. There is a variation in color, especially when breaking over texture, but not as strong a mottling effect as in the cone 6 recipe. There is crystal formation throughout the glaze. Good coverage from the glaze, with no pin holes. The glaze is of low viscosity and will tend to be runny.