multiple investment casting waxes from soft tooling

From: RP Solutions (
Date: Tue Mar 02 1999 - 16:06:21 EET

Hi RP ers,

Perhaps someone out there can help us, we are an RP service bureau based in
Coventry in the UK.
We have been investment casting parts from FDM masters in ABS with some
success, however we would now like to make multiple waxes from vacuum cast
silicone ( RTV ? ) tooling.

We have no experience of producing waxes in this way so I would be grateful
for any advice on how to proceed.

Here are some of my questions:

Is it ok to use normal foundry IC wax or is there another type with zero

Is shrinkage of the wax a problem or can it be compensated for on the RP

what shore hardness and type of silicone should be used for the tool?

Does a silicone tool need a metal insert to reduce cycle times for the

Is tool construction unique to the process? ie do you need to produce a
tool that splits many times to be able to get the waxes out?

How should the wax be poured? under vacuum or injected in atmosphere, does
the tool need to be heated as well.

How do companies like MCP get their systems to work?

Are there other routes to making multiple waxes from an RP master that work

Many thanks for your time, I look forward to reading the responses.

Oliver Cole
RP Solutions

Tel: 01203 632120
Fax: 01203 632131

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