Practice question · Multiple choice
A waste mould resolves undercuts by destruction rather than division or stretching. What does this principle imply for the positive cast and the original model?
Hints
- What physical state is the original clay in when the casting material is poured into a waste mould?
- How is the positive cast freed once the casting material has set?
Show the answer
D. The model is lost during demoulding and only one cast is obtained
Why
Waste moulding is a sacrificial process at both stages: the original clay is hollowed out to pour the positive, and the plaster is chipped off to release it. Thinking the original survives confuses waste moulds with piece moulds, while flexibility applies to rubber liners.
Practise Moulds I: Typology
The app has 5 more questions on this lesson, and keeps your place in the course. Sculpture I is free to start.
More questions on Moulds I: Typology
- Sort each mould by how it deals with undercuts.
- Why does a flexible silicone mould usually need a rigid mother mould over it?
- Addition-cure silicone can be prevented from curing by contact with sulphur-containing plasticine.
- Which are true of alginate as a moulding material?
- Complete the mould vocabulary.
- What is the minimum number of rigid mould pieces needed for a form with no undercuts at all?
- Arrange the steps of deciding how to mould a form, in order.
- The division lines of a piece mould can be placed anywhere, since the seams are cleaned off the cast…