art253glazeexper

FUSION OF GLAZE MATERIALS

This experiment will demonstrate the effects of various glaze materials on the melting of feldspar. It is a demonstration of the principle of eutectics.

General Instructions:

First, make eighteen tiles using Long Beach Blend clay. The tiles should be three by three inches, three-eighths inch thick. Dry and bisque fire the tiles.

Make a series of line blends with the two feldspars and Nepheline Syenite and the additional material assigned to you. Each line blend will be in six steps, with a pure material at each end and four mixtures in equal steps on the four remaining tiles. This will be explained and demonstrated in class. Each of the six steps in each blend will be placed on an individual tile, appropriately marked on the bottom. See the illustration below.

The Feldspars

A. Custer Feldspar

K2O .69 : Al2O3 : SiO2

Na2O .31 1.05 7.05

B. Kona F-4 Feldspar

K2O .32 : Al2O3 : SiO2

Na2O .48 1.02 5.60

CaO .20

C. Nepheline Syenite

K2O .25 : Al2O3 : SiO2

Na2O .75 1.11 4.65

The Materials

1. Whiting- CaCO3
2. Barium Carbonate- BaCO3
3. Magnesium Carbonate- MgCO3
4. Zinc Oxide- ZnO
5. Dolomite- CaCO3:MgCO3
6. Talc- 3MgO: 4SiO2: H20
7. Wollastonite- CaO: SiO2
 

 

Mark the tiles on the bottom using underglaze pencil before applying the material, as illustrated below. This would be a set of tiles for Custer Feldspar and Whiting:

COLOR IN GLAZES

This experiment is designed to allow you to more fully understand the role that the various oxides play in the development of a ceramic glaze. In particular, we will be looking at the influence on the color, texture, and melting characteristics of the glaze.

General Instructions:

1. Determine the eutectic point from the first glaze experiment, Fusion of Glaze
Materials. Mix 1000 grams of that glaze, dry.

2. After thorough dry mixing, divide the dry batch into ten one-hundred gram
batches.

3. Mix the one-hundred gram batches with the following additions:

a. 2% Red Iron Oxide

b. 8% Red Iron Oxide

c. 1% Cobalt Carbonate

d. 1% Copper Carbonate (plus 1% Tin Oxide)

e. 3% Manganese Carbonate

f. 4% Rutile

g. 1% Ilmenite

h. 1% Nickel Oxide

i. 1% Chrome Oxide

j. 1% Iron Chromate

4. Mix the one-hundred gram batches with the appropriate amount of water and apply to your stoneware and porcelain (or white stoneware) tiles. Fire in a cone ten reduction firing.

Record the results on the forms provided.