Zen and the Art of Prop Making

There are many occasions in theatre and film where latex bladders of a specific shape and size are needed for props or special effects. Sometimes a commercial product can be adapted but generally they need to be made This simple technique can be adapted to make latex bladders for any situation. The steps involved in the process were originally developed for the construction of a spurting blood razor for the 1998 Opera Australia production of "Sweeney Todd". Steps to make latex bladders The following steps illustrate the principle of making latex bladders for a specific purpose. They can be adjusted as necessary to adapt to the intended use required. Step 1 The original CAD drawings of the razor were used to produce DXF files and the razor part were laser cut in aluminium. When the parts were assembled the handle had a hollow recess into which a clear Perspex trigger handle could slide. Squeezing the trigger handle into the body of the razor compressed the blood fi

A latex mould is a nice compromise between a fibreglass mould and a silicone mould. They take a little longer to make but they are more flexible than a solid fibreglass mould and much cheaper than silicone rubber. A latex mould will deteriorate over time since it is a rubber compound but thisis generally not an issue. As with fibreglass moulds you can have several sections bolted together. Small undercuts are not a problem with latex because of it's flexibility. Step by step latex mould making For a description of latex mould making we will make a two part mould of a deer head. The following steps are the general ones to follow regardless of what you are moulding. Step 1 Build a flange around the middle of the head where the mould will split. Fill all gaps with plasticene so that there is a clean right angle join between the object surface and the flange. This minimises any join marks when the two halves are bolted together. It's a good idea to place a few small 12m

A plaster mould is the easiest and cheapest of all moulds to make. They are also the heaviest and most fragile. There are two basic ways of making them. The method described here is to use plaster bandage which is normally used to set broken limbs. The other method is to pour the plaster into a mould box which is described in another post on Plaster Mould Making . Simplicity of plaster bandage moulds A plaster bandage mould is useful when taking moulds of body parts because it dries quickly and has no harmful solvents. Plaster bandage can also be applied directly to an object without having to make special dams or walls to contain it. To save money it can also be used as a support jacket in lieu of fibreglass when making a latex mould. Step 1 For the purpose of description we will take a plaster cast of a foot. You need to put a release agent onto the skin to prevent the plaster sticking on skin or hairs. Even though it's messy, petroleum jelly is the best to use. Ev

A silicone mould is much more forgiving with undercuts than one made from fibreglass because they are so flexible. A silicone mould is used more for casting urethane foams and resins to make solid objects. They are excellent for making bottles and glasses and usually have a cut down one side to make it easier to remove the cast. A wooden box or tube is used around the mould to support the silicone rubber when it is filled with casting material. A silicone mould is easy to make but the materials are expensive. You need to balance the size of your object with the size of your wallet. That being said they are robust moulds and can give many impressions. For the purpose of description we will make a mould of a engine cylinder head for a full-size prop replica of a Wright Cyclone radial engine. Cylinder head silicone mould The following steps describe the construction of a silicone mould and casting of a prop cylinder head for an aeroplane engine. This replica Wright Cyclone engine

A simple as hoc lathe can be made in a matter of hours to turn polystyrene foam. You will need access to a MIG welder, metalwork tools and some scrap RHS steel to make the frame and bracket to mount the drive motor.The size of the frame of the simple lathe will depend on the size of the block of polystyrene you will be working with. Fitting polystyrene to the simple lathe Prepare the polystyrene block for the simple lathe by glueing two circular pieces of 12mm plywood on both the ends of the block. This gives a solid mounting point to fit the polystyrene into the lathe. The long edges of the block are trimmed at 45 degrees to make it easier for the initial turning. Step 1 The heart of the lathe is an electric motor that has a small pulley fitted to its shaft. I used an electric motor from an old gem tumbling machine but any electric motor that is available is suitable as long as it has enough torque to turn the polystyrene block. A larger pulley on a short shaft is fitted thro

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

Several Japanese style lanterns were required for a terraced garden. They were made from Merbau and fitted to the top step of several stairs between the garden terraces. Construction was relatively straight forward as is indicated in the photos below. The individual timber strips to make the lattice windows was cut from Merbau planks which had been cut to 10x10mm lengths. These were then assembled into the window lattice frame and glued into position. After all the lattice windows were made they were fixed into square timber frames made of 20x20mm Merbaus. Translucent perspex windows were cut to fit behind the wooden lattice frames to diffuse the LED lights. Additional diffusion was obtained by mounting the LED's inside white plastic milk containers. The perspex windows were held in place by wooden blocks fitted under the removable lantern top. The photos below show a completed lantern before installation in the garden.