Glaze Experimentation Notes These notes are for use in Louis' classes and lectures. They are not intended to used as stand alone instructions. Glazes and glaze ingredients may be hazardous to your health.

Safety

• All Glazes formulated by students should be evaluated for suitability on functional ware.
• Inhalation of glaze ingredients should be prevented.
• Other safety measures should be used when appropriate including eyeware and gloves.
• Material Safety Data Sheets (MSDS)

1. Application tests
2. Published recipe tests
3. Variation tests
4. Basic Glaze formulation tests
5. Process test

Application tests

• Over and under tests
• Over and under thickness variations and how to acheive them
• Oxide and stain use
• Brush and trailing, spattering
• Floculation and spooning.

Published Recipe Tests

• Choosing and finding recipes
  • Online
  • Technical Sources
  • Phase Diagrams
  • Books

Variation Tests

• Colorant Substitutions and modification
• Textural Modifications
  • Substituting Dolomite for some of the whiting
  • adding Titanium Dioxide
  • adding Zirconium silicate opacifiers
  • Substituting Strontium Carbonate(.75) for Barium Carbonate(1.0)
  • Substitue Zinc Oxide for Whiting
  • at cone 6 add Neph Sy to glaze up to 50%
  • add 5% Soda ash to a glaze.
  • add .5% silicon carbide powder extra fine for reduction effects, coarse for bubbles
• Line Blends
  • Make a line blend between two glazes. The glazes may not have restricted use chemicals in them. If you have already completed this project once in a previous class, repeat it or find a glaze from anyone's previous line blend, mix up a 1000 batch from dry materials, and test it with the class glazes and slips. If you have other glazes you want to test instead bring the recipes to the instructor.
    • Mix 1000 grams of two glazes.
    • Choose cone ten glazes that have different ingredients, surfaces and colors. Discuss your choices with your instructor
    • Mix the glazes a bit on the thick side, but still liquid.
    • Sieve both glazes.
    • Water down one of the glazes so that they are both the same volume.
    • Glaze a test tile with glaze B mark it 0
    • Glaze a tile with 1 Tablespoon(T) glaze A and 5T Glaze B mark it 1
    • Glaze a tile with 2T Glaze A and 4T Glaze B mark it 2
    • Glaze a tile with 3T glaze A and 3T Glaze B mark it 3
    • Glaze a tile with 4T glaze A and 2T Glaze B mark it 4
    • Glaze a tile with 5T glaze A and 1T Glaze B mark it 5
    • Glaze a tile with glaze A mark it 6
  • If you do the same process with glazes already mixed it will only indicate if more tests to determine an exact recipe should be done.

Basic Formulation Tests

• Many interesting effects come about from breaking out from normal glaze formulation guidlines. Usually this results in glazes not useful for functional ware.
• Changing the materials used but keeping the unity formula constant can produce interesting variations.
• glazes long on one type of flux(Alkaline, alkaline earth, boron, zinc etc.) often produce interesting glazes.
• glazes slightly to moderately overloaded with a coloring oxide or some other oxide can produce interesting results.

Process Tests

• Fire in oxidation and normal reduction
• Raku it many ways
• Slow the cooling , try a crystalline glaze type scedule
• refire reduction glazes to a lower cone in oxidation
• cool in reduction
• cool in water vapor (don't blow up your kiln, or electrocute yourself from water or condensation and electric kilns.

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