CASTING
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Mould
Making
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Mould Making
It comes as quite a surprise to most people to learn that pewter and other tin alloys can be cast successfully into rubber moulds (without the mould melting or catching on fire!). Two sorts of rubber can be used RTV silicone rubbers are cold curing, they come in a liquid form and are hardened by addition of a catalyst. Vulcanised rubber moulds (both organic and silicon based varieties are available) are cured by heat and pressure and are the first choice of the industry. They have been commonly used for casting pewter and other tin alloys for more than 50 years.
RTV
silicone rubber moulds
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Advantages
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Disadvantages
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Vulcanised
rubber moulds
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Advantages
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Disadvantages
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Siilcone
or Organic vulcanised rubber?
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Vulcanised rubber is available in organic and silicon the finished product can be essentially the same but there are some distinct differences in use. |
Silicone
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Advantages
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Disadvantages
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Organic
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We make moulds for customers who also take advantage of our Contract Casting Service
We only make vulcanised moulds usually organic or low temperature silicon. To make a mould we need a master, this could be made from pewter or many other metals or epoxy putty (such as Milliput) or a combination of these. We can offer advice on the suitability of a particular material. Normally for machine casting a master mould is made containing numerous different ietms, this is used to make multiples of each from which a production moulds can be made containing numerous examples of the same design. In this way the casting conditions can be matched to suit the particular object. Sometimes making a separate mould for each can't be justified and so items which have similar bulk etc. are placed in the same mould.