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Glaze Leaching Test - GLLE

This test procedure was employed in the Foresight Ceramic Database and now is available for those having an account at Insight-Live.com. Accumulating test data using the variables defined in these procedures enables us to create tools that enable you to compare the physical properties of materials and recipes.

Notes

All glass leaches to some extent when it comes into contact with water (or acids and bases), especially if the contact occurs over a period of time or the liquid is hot. This is evident by a change in the gloss and/or texture of the glass surface over time. Glazes can pass a test of acid attack (e.g. lemon juice) yet fail the attack of bases (e.g. detergents). These simple tests can be done by anyone. After each dry the specimens and compare the non-leached and leached surfaces for difference in color and gloss.

Vinegar Test: Fill a glazed container half full of vinegar and leave it for several days. If the vinegar turns yellow, this is an indication of lead release.

Dishwasher Test: Take two identical items and put one in your cupboard and leave one in the dishwasher for two months.

Soda Ash Test: Mix 50 grams of soda ash to one liter of water, bring to a boil in a stainless steel pan, simmer glazed specimens for 6 hrs checking every half hour to add more water.

Lemon Slice Test: Lemon juice is more acidic than water (actually it is even more acidic than vinegar). Place a lemon slice against a glazed surface and leave it in contact for several days. Make sure that it is in close contact with the surface and stays wet (put plastic wrap over it to keep it from drying out and a weight on top if needed). Look for differences in surface color, texture or character.

Variables

VNGR - Vinegar (V)

Note any differences surface color, texture or character.

DWSH - Dishwasher (V)

Note any differences surface color, texture or character.

SODA - Soda Ash (V)

Note any differences surface color, texture or character.

LEMO - Lemon Slice (V)

Note any differences surface color, texture or character.

Out Bound Links

In Bound Links

  • (Tests) GLFL - Glaze Melt Flow
  • (Articles)

    Concentrate on One Good Glaze

    It is better to understand and have control of one good base glaze than be at the mercy of dozens of...

  • (Oxides) CuO - Cupric Oxide
  • (Glossary) Food Safe

    In recent years potters and small manufacturers ha...

  • (Glossary) Glaze Durability

    Ceramic glazes vary widely in their resistance to ...


By Tony Hansen




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