(c) If used during the winter what precautions are observed?
4. (a) Mention two materials which are used extensively for building up ovens and doing the preheating.
(b) What kind of brick is used?
5. (a) How much should cast iron be preheated?
(b) Brass or bronze?
(c) Aluminum?
6. Sketch and describe how a temporary brick preheating oven should be built, giving all dimensions, such as: length, width and height and reasons for them.
7. Explain how a cylinder block with a broken water jacket is set up for preheating; how oven is built for charcoal fire; how fire is started; how block is protected while welding and how it is returned to a cold state.
8. (a) What precautions are necessary in setting up and preheating aluminum?
(b) If piece is to be turned while in the fire, what provision is made in building up oven?