Practice question · Select all that apply
Which are true of quartz inversion at about 573 degrees?
Hints
- Three describe the inversion; one confuses it with glaze maturity.
- Glazes melt far above this temperature.
Show the answer
- B. It occurs on heating and again on cooling
- C. Passing it too quickly in either direction can crack the work
- D. Silica in the body changes crystal form with a sudden volume change
Why
The second point is the one that costs people firings. The inversion happens on the way down as well as up, so opening a kiln early to see the results is a reliable way to crack a load that survived the climb perfectly.
Practise Firing
The app has 4 more questions on this lesson, and keeps your place in the course. Sculpture I is free to start.
More questions on Firing
- Why do pyrometric cones remain in use alongside electronic temperature control?
- The same glaze recipe produces the same colour regardless of kiln atmosphere.
- Sort each statement by whether it concerns the BISQUE firing or the GLAZE firing.
- Complete the account of firing.
- A kiln firing is defined as an entire schedule rather than reaching a single peak temperature. What practical…
- At approximately what temperature, in degrees Celsius, does quartz inversion occur?
- Match each firing atmosphere or concept to what it means.
- Arrange the stages of a firing schedule in order.
- A body bisque-fired too high may fail to absorb glaze properly.