Hi
Please note not a teacher nor a native speaker.
I understand that you use cast and mould as verbs.
I did a little research and it seems that mould is used mainly with things that have high plasticity, and the shape can be given using hands or simple tools.
such as :
plastic
clay
wet sand
wax
gold
silver
cheese
flesh
body
breasts
shape
personality
life
PS.
Cheers
You have mentioned the names some materials and terms used in the process.
Moulding and
casting are primarily two different engineering processes for manufacturing parts or goods having different shapes. Modern manufacturing processes use varieties of moulding and casting techniques applicable to specific materials.
For example:
injection molding is the most commonly used manufacturing process for the fabrication of plastic parts or goods.
Pressure die-casting is used to manufacture of aluminum/brass/other metal parts .
These are mass manufacturing processes for making standard products. However, for making non standard products and items in small quantities, a process called
sand casting useing wet sand(mostly manual)is employed.