REVIEW Ceramic Glaze a mixture of powdered materials made into a formula that fuses onto a ceramic piece when heated through Silica the glass former found naturally in sand Flux the temperature reducer helps the glaze melt ID: 576758
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Ceramic Glazes
REVIEWSlide2
Ceramic Glaze
a mixture of powdered materials made into a formula that fuses onto a ceramic piece when heated through
Silica
– the glass former; found naturally in sandFlux – the temperature reducer; helps the glaze meltAlumina – the stabilizer; keeps the glaze from running off of the ceramic piece; helps glaze stickSlide3
Finishes of Ceramic Glaze
Underglaze
– can be applied to
greenware or bisqueware; matte in finish; not food safe on ownUsed in pottery to add intricate designs or patterns to the surface of the clay before being glazedUnderglaze pencils can be used to add small detailsSlide4
Finishes of Ceramic Glaze
Liquid Glaze
– a type of glaze that produces a high shine/gloss,
semi-matte, or matte finish on the surface of ceramics; mostly food safeused over underglaze work to make it food safecan be used on owncomes in all colors, from clear to blackSlide5
Can you eat/drink off of your pottery?Slide6
How to Apply
glazes appear differently with different applications
Opaque color = 2-3 layers Semi-Transparent = 1 layerSlide7
How to Apply
Glaze can be applied by
dipping
, pouring, brushing or spraying onto the surfaceBottom of piece must be free of glazeWill fuse to the kiln shelf
OR bottom can be glazed, but stilts will be usedTo prevent from fusing to shelf Slide8
Can you mix
Glaze?
Most glazes can be mixed together, just like you would paint
Mixing can produce different colorsLayering glazes can produce different effectsSlide9
Glazing Problems
Crawling
– empty spots left on a ceramic piece due to
oil or dirt on the greenware/bisqueware pieceCan also be because of a thick application of glazeA glaze formula that has too much or not enough of silica,
flux, aluminaSome artists purposely do this, others, it happens on accident Slide10
Crazing
When the shrinkage rates of the clay and the glaze differ from one another
Tiny cracks appear in on the surface
After it is removed from kilnAfter a couple of weeksSlide11
Running/Pooling
When glaze runs over and down your piece, sometimes pooling on the kiln shelf
Happens when too much glaze was appliedSlide12
Blistering
Result of escaping gas when the glaze is firing too fast or the coat of glaze is too thickSlide13
Pinholes
Little holes that result from air holes in the claySlide14
Rough Surface
A rough surface (not glossy) that results from applying a thin layer of glazeSlide15
Consistency
Glaze should look/feel like thick milk, cream or pancake batter
Not too thick, not too thin
Glaze needs to be shaken in the bottle and stirredSediment can settle to the bottom of the glaze bottle and needs incorporatedWater can be added to dry, chunky glazeLet sit overnight and stir next daySlide16
Color
Due to chemical reactions that happen during the firing process, the color of glaze greatly changes within the kiln
Check test tiles hanging below the glaze
No test tiles? Go on the glaze brand’s website and check