Read instructions
Identify the product and specified proportion and method.
MEDIVEERSETHE PRACTICAL HUBOBSERVE / REASON / EXPLAIN
Gypsum mixing and cast quality
Explain variables that affect a teaching gypsum cast.
Your practical station
Two student casts show different surface defects. Explain the mixing and handling variables you would review before repeating the exercise.
Recognise and interpret
Water-to-powder ratio, mixing and handling affect gypsum setting and the resulting cast properties.
Observe
Record consistency, working time and setting observations in the practical.
Inspect
Describe bubbles, fractures and surface detail after the prescribed set.
At the viva table
Try answering aloud, then open the suggested answer. Examiner questions vary.
01 / Should extra water be added casually to a setting mix?
No. Follow the product instructions; changing proportion alters properties.
02 / Why distinguish working and setting time?
They describe different stages of handling and hardening.
03 / What can trapped air cause?
Voids or defects in the cast.
04 / Does one gypsum type suit every application?
No. Select according to intended use and required properties.