Produce components from moulds two gauge casting

Producing plaster components Introduction Aims: To introduce fibrous work Objectives: To recognise and understand the processes used in two gauge casting

Producing plaster components Two gauge casting Can you answer the following? What are firstings? What types of reinforcement are used in two gauge casting? How is the plaster applied to the mould? List the processes involved in two gauge casting What is size used for?

Producing plaster components Introduction Two gauge casting Two gauge casting is used to produce all manner of fibrous plaster items. The main qualities expected from two gauge casting is to produce a strong lightweight product. Two gauge casting can be a long and complicated operation so preparation is everything. Unlike one gauge, care must be taken to prepare the reinforcement before any mixing takes place, so all laths and canvas must be cut to size before the casting process starts.

Producing plaster components Introduction Two gauge casting Prepare reinforcement materials (hessian face and backing cut to size lathes that have been soaked Prepare two amounts of water (firstings and seconds) Add required amount of retarder to the seconds (you need to know how strong it is to give you time to complete the cast) Mix the secondings first and the firstings second Using a splash brush on the firstings and then splash on the mould Clean off the strike offs

Producing plaster components Introduction Two gauge casting (cont.) Apply the seconds to the mould Put the canvas in place and brush in with the seconds Position the ropes and lath reinforcement Apply the rest of the mix to give some thickness to the back of the cast Place reinforcing wads on the back of the cast Strike off the mould to complete

Producing plaster components Two gauge casting You should now be able to answer the following: What are firstings? What types of reinforcement are used in two gauge casting? How is the plaster applied to the mould? List the processes involved in two gauge casting What is size used for?

THANK YOU