Hello, 
I am going to make some Uni-mould moulds from original parts that are too light and delicate to see any heat or pressure. Then, I am going to make pre-preg parts from the moulds.

I just wondered what peoples experiences of this were...
What temperatures have you used the moulds to? What pre-preg have you used in the moulds? Etc...

In another thread, Hanaldo suggested an extended post cure which I intend to do. Someone else mentioned board sealer which could be a good shout as I have spray facilities for this.
I also have access to an autoclave for when I make the final part. Obviously, the integrity of the mould will come down to how well it is laminated but I was hoping to use a prepreg that might be a little more suited to OOA/lower temp cure. I have looked for VTF261 but may end up with VTC212 or similar. 
Any pointers on this will be much appreciated as I have a few projects coming up that would be suited to this process (if it works!)
Many thanks in advance!

Generally the XC110 system is meant for out of autoclave use so vacuum bag only should be sufficient.  However a bit of extra pressure would likely be fine on the pre-preg itself.  It might be possible with too much pressure to squeeze out some resin but without specific testing its hard to know in practice if that may be an issue. 

The Uni-mould and many wet lay up mould systems are not generally rated for autoclave use due to the issues with voids and fibre consolidation.  Even if voids don't collapse or burst through, it may be enough to set up stresses in the mould that lead to cracks in the gel and accelerated mould wear.

Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant