WORKING WITH PLASTIC - not as easy as it looks !


You will be working with a piece of acrylic,called "Perspex", to make your Key-fob from. "Perspex" is a "brand-name": a manufacturers choice of name given to a product, e.g. "Coke", "Big Mac", "Branston" etc. By the end of year 7 you will probably realise that plastic is, in fact. More difficult to work with than wood or metal. "Perspex" will crack, split, scratch and break very easily. Once it is damaged, there is little or nothing you can do to repair it! Therefore you must take extra care while working with plastic. Over-tightening a metal vice too much will even spoil a piece of plastic, as it will produce a criss-cross pattern into the shiny surface.

Marking-out lines on plastic should be done with a permanent marker-pen. If lines are wrongly scratched into the surface they will remain there! Ball- point pens can be used if the acrylic has a thin layer of white film protecting it. Do not remove this protective cover until the very end of the project. Keep work positioned very low in the vice and cut with extra care; as "Perspex" breaks so easily.

Coping saws are ideal for cutting acrylic but all cuts must be done close to jaws of the vice. Once the shape is completed and filed smooth, the edges can be rubbed-dov/n using "wet and dry paper," along with water. The edges can also be polished, as this will also improve the appearance. Finally,remove the protective film, which covers the surface.

VACUUM FORMING MACHINE
Your biscuit cutters will be produced on this machine. It is very easy to file acrylic but try not to give yourself too much filing to do. Once again, it is easy to be unlucky and make a single mistake; which cannot be corrected.
Greater time and care should be taken to "saw" very close to the required shape and size; so that you are left with Just a small amount of filing.

Vacuum forming machine