Question

_____________ Binders are used to harden the skin dried moulds.

(a) Linseed Oil

(b) Marine Oil

(c) Vegetable Oil

(d) Synthetic Resins

The question was asked in an international level competition.

This intriguing question comes from Type of Sand Moulds topic in section Sand Moulding of Foundry and Forging

Answer 1

The correct option is (a) Linseed Oil

To elaborate: Linseed oil is added with molding sand in the green condition and then the skin of the mould cavity is dried up with the help if gas or flame torches. The structure after drying appears to be like dried skin. Hence the name is Skin dried moulds.