Zen and the Art of Prop Making

Fibreglass moulds can be a one piece mould or, if the object has a complicated shape, made in two or more separate pieces bolted together to make the final mould. This makes removal of casts from the fibreglass moulds possible. There have been many unhappy souls who have made a cast in fibreglass moulds only to find they cannot remove them. There is no flexibility in fibreglass moulds so things will get permanently stuck if there are any undercuts. Main points of fibreglass moulds The aim is to make the surface of fibreglass moulds as smooth as possible. If the surface quality of the mould is like a mirror then the cast object will be the same. The extra care taken in making the mould will reap rewards when casting later. Mould release agents or wax should always be applied to moulds before laying fibreglass matting. The following steps are a general guide to making multi-section fibreglass moulds. Step 1 You must carefully plan where you want fibreglass moulds to split. In ...

The first step in making a giant egg is to make a giant egg! From this a mould can be made from which to cast as many eggs are required. Depending on the size of the egg you want to make will dictate how you go about making the egg form. Since the egg we needed to make was about 60cm tall it was decided to carve it from a block of polystyrene. Since the egg shape is symmetrical it is best to turn it on a lathe. The polystyrene has to have plywood boards glued to both ends so a lathe faceplate and tailstock centre can be attached so it can be turned on the lathe. The corners of the block are then cut off at 45 degrees to make turning a bit easier on the polystyrene. If this is not done it is likely large chunks will break off when the lathe chisel is applied to the turning block. It is very, very messy turning polystyrene on a lathe so ensure the work area is covered with something to collect the shavings and clean up regularly as you work. This will minimise the polystyren...