What are the most common mould-making materials?
Once you’ve completed a model, you may want to create a negative impression of the model in the form of a mould so you can easily replicate the model later. You can create these moulds by using specialist substances and equipment designed for mould-making, such as the types of mould-making materials we supply right here at Alec Tiranti.
There are many types of materials you can use for mould-making, depending on how the original model was made, how the reproduction will be cast and the level of detail required. Using these materials, you can cast reproductions in products as diverse as plaster, plastics, cements, and waxes. Here are five of the most common mould-making materials so you can pick the best one for your purpose:
Vinyl rubber is a handy mould-making material which can be heated using an electric melting pot or carefully using a domestic hob and poured over a sculpture to cool. One example of a vinyl rubber material is Vinamold which is made from PVC resin. One advantage of creating a mould from vinyl rubber is that vinyl rubber is suitable for casting a wide variety of materials. Being so flexible, vinyl rubber casts also require no preparation or release agents to remove and are even re-usable as they can easily be re-melted to form a new mould.
In contrast to vinyl rubber, silicone rubber is a cold curing mould-making material, meaning that it vulcanises at room temperature. Silicone rubber can also be used for most applications, thanks in part to the diversity found in different choices of silicone moulding material. Some silicone rubbers, such as RTV-101, are durable enough to able to work up to higher temperatures, making them useful for moulding metals such as tin alloys and pewter.
Like other mould-making materials, polyurethane rubber is suitable for a range of castings including plasters and concrete. Boasting similar hardness to a pencil eraser with its 40A hardness on the Shore durometer, polyurethane rubber is a two-part rubber which is a great choice for tough casting applications such as industrial parts and special effects departments. One downside of polyurethane rubber is that it relies on the use of a release agent to remove it from properly prepared models.
Latex modelling is one of the most recognisable mould-making applications, regularly used by film and TV special effects departments worldwide. Like silicone rubber, latex comes in a pre-vulcanised liquid form and dries at room temperature, making it excellent at creating strong strip-off moulds. You can either dip the original model into the latex, or paint layers of latex on the material. As this can be a time-consuming process, there are other latex moulding materials available such as thickener to speed up layering.
The final mould-making material we would like to highlight is alginate. This non-toxic material can take quick and highly detailed moulds from almost any material and prized by sculptors, model makers and those working in film and TV for its ability to be applied anywhere on the body to create body part moulds. Alginate sets when mixed with water and generally comes in two forms: normal set, which enables plaster or wax casts to be taken immediately, or slow set, which is ideal for larger and more complex moulds such as full-face moulds.
Here at Alec Tiranti we are proud suppliers of all five of the above mould-making materials, as well as other mould-making equipment. If you are wondering which would be the right material for your mould-making then why not contact us today? We can have you and your mould set in no time.