Selection & Application of Materials & Equipment for Ceramics Flashcards

Which ceramic colorant produces a reliable blue color in both oxidation and reduction firing atmospheres?

Answer: Cobalt oxide

Cobalt oxide consistently produces blue color across different kiln atmospheres, unlike iron and copper which are highly atmosphere-sensitive.

What is the primary function of a pug mill in a ceramics studio?

Answer: Reclaim, deair, and homogenize clay

A pug mill reclaims scrap clay by compressing and de-airing it through an auger system, producing a homogeneous, air-free clay body.

When applying glaze by spraying, which factor most directly controls the thickness of the glaze application?

Answer: The specific gravity of the glaze and number of spray passes

Spray thickness depends on how much material is deposited per pass, which is governed by glaze specific gravity and the number of overlapping spray coats.

Which material is commonly added to a clay body to open the texture and improve resistance to thermal shock in raku ware?

Answer: Grog

Grog (pre-fired, crushed clay) opens the clay body, reduces shrinkage, and improves thermal shock resistance critical for raku's rapid heating and cooling.

A glaze recipe calls for a high amount of calcium carbonate (whiting). What role does calcium serve in the glaze melt?

Answer: High-temperature flux and stabilizer

Calcium functions as a high-temperature flux that lowers melting point and also stabilizes the glaze melt, improving durability in the fired surface.

Which type of pyrometer is best suited for continuous, real-time monitoring of kiln temperature throughout a firing?

Answer: Thermocouple pyrometer

Thermocouple pyrometers generate an electrical signal proportional to temperature, allowing continuous digital readout and controller integration throughout the firing cycle.

When wedging clay, what is the primary goal of the spiral (rams head) wedging technique?

Answer: Align clay particles and remove air pockets without trapping air

Spiral wedging uses a continuous rotational push that progressively expels air and aligns clay platelets without folding air back into the mass.