How do I use latex?

Latex is a cheap and easily sourced material for both mould making and casting purposes. It is best used in conjunction with a plaster mould or casting as the porosity of the plaster assists in the curing process of the rubber. Latex does not bond to most non-porous materials. If you do you a nonporous material each layer must be allowed to dry completely before the next can be added.

Remember, do not use Vaseline or any other petroleum-based products as a release agent for latex, as it will accelerate the rate at which the mould decomposes.

Dipping latex, skin casting, mould making

A vessel filled with liquid latex can be used to make simple, quick latex skin moulds as a substitute for silicone. Using a dry plaster master, suspended by its base, submerge it completely into the latex. The longer the plaster is left submerged in the latex, the thicker the coating will be. As a general guide 15 minutes should build up an adequate layer thickness for very small moulds while as much as an hour will be needed for larger mould making. All latex moulds should be left for 24 hours to cure fully before being powdered with talcum powder to prevent it sticking to itself prior to removal from the plaster master.

Latex is available in The Bonington Shop or :

Alec Tiranti sculpting supplies

Prices vary:

£8.00 per kilo

    Prefabricated latex tube stretched over two hundred dining chairs suspended from the ceiling
    Latex must always be treated with talc to   
            prevent sticking upon removal
        Brushed latex mask
       Rollered latex sheet
Brushed, pigmented latex mask stitched with hair

Brushing and rollering latex for casting and mould making

When using brushing techniques to make a skin on anything other than dry plaster, first paint a layer of latex on the surface of the master you are using to make your mould and wait until dry (turns from milky white to translucent toffee colour when dry). You can accelerate this process with heater fans, hair driers or hot air guns set on low so as not to scorch the latex.

Continue to build your layers of latex until you have achieved the desired thickness.

To add strength to your latex skin mould, layers of cotton gauze or bandage can be used to stop tears and eliminate extensibility (stretchiness) while still maintaining most of its other mechanical properties.

Once the desired thickness has been reached, a jacket should be used to retain the shape and form of the original master, before it is removed. Plaster, mod-roc or fibreglass are popular choices for jacket making although other materials can be used.

What is latex?

Latex is a gum extracted from the rubber tree, native to Brazil, Mexico and the Caribbean. It is unique in the sense that it is also a natural rubber polymer; a water-based liquid that emulsifies on contact with air forming a rubber like skin. The Inca, Mayans and indigenous peoples of Haiti used latex to make bouncing rubber balls and hoops to play an early version of basketball, but they also used it as a coating to water proof and protect their feet and storage containers, over 900 years ago.

Thanks to Christopher Columbus, latex is still in use today, mostly as a chemically modified version. These modified forms of latex are all around us and are still used in industry too. It is used to make elastic bands, balloons, face masks, toys, hot water bottles, rubber balls, prop making and protective medical gloves, it can also be used to coat polystyrene sculptures allowing it to be spray painted or fibre glassed. Most importantly, it was used in a process called vulcanisation (the addition of heat and sulphur to latex) by Charles Goodyear in the 1800’s to make the first rubber tyre; production methods of modern car tyres has changed little since then.

Tapping natural latex from a rubber tree

Latex- Brushing and dipping