Help finishing mold.

Hi Guys,

I am getting some parts machined at the moment for some molds.

They are made out of a layered stack of MDF into a shape pretty well like this:



Now I am wondering how I need to finish the wood, and what steps I need to go through before casting off of it each time. I will mainly be making the parts from fibreglass, but may attempt to do it from concrete at some point.

So I am wondering what products I need, and in what order do I need to do them in? The parts need to be very smooth.

Also, will there be any issue with the MDF possibly swelling from the PVA used to build up the mold?

Thanks,

Ryan