Originally Posted by
josef1
the fisrt one is cast and polished then a mould is made from this its called a master and copys can be made from that by injecting wax into it but they will be smaller than the master as you have 2 lots of shrinkage to contend with.The master has to be sized to allow for the shrinkage of the full process. sometimes a sizing part will be built into the ring so you only need a few moulds as you can size the ring up and down a few sizes, depending on the design. Also you can size the injected wax model a certain amount