Generally, components are post-cured in the mould in which they were laminated. There are some steps that can be taken to ensure the mould does not distort.
Moulds that are subject to repeated use should be post-cured at a higher temperature than that required for the finished component. This allows the part to be post-cured in the mould at a temperature below the mould’s HDT, thereby avoiding distortion of the mould, mould surface or the component during the component post-cure.
Plugs used to build moulds should be post-cured at higher temperatures than the mould to avoid distortion of the plug or plug surface while the mould is being post-cured. Check plugs for fairness after post-curing and fair as necessary before the mould is fabricated.