[peteeng]

Hi BH - I haven't used Partall but its a common brand and spec for low temp cure. It will be fine for the job just make sure it has enough on use the masking tape test and let every coat cure proper before the next coat.... follow the directions and it will be fine. Silicone is great but can transfer if sprayed or knocked over! Don't ask...
I'm not sure PVA helps in your case as you are disassembling the mould and styrene transfer is not in the mix... But PVA is sort of an insurance policy if your uncertain of the process or use it in places you think maybe a bit tight to remove.... Keep us in the loop... Peter

I like liquid waxes less elbow grease gets on the mould.... apply with rag not sprayed... plus this is good for coating nuts and bolts and various bits that you may not want to get stuck to the mould or part. Use in well ventilated place, generally uses naptha as solvent and its a bit heavy duty on the human system..

Another suggestion is to use mylar tape. Packing tape is commonly used for one off moulds where surface finish is not important. A packaging company may have a wide sticky tape that you can apply to the surface. Then a quick wipe with wax and your done... for instance in the photo attached there is no wax involved. The timber has been wrapped with clear packing tape and the melamine has a plastic film on it... this is an epoxy infusion of steel and other fibres.. Mould is dry stacked then use vacuum to pull epoxy resin through the part. You could do this as well but keep going the way you know... That mould has been used 3 times no wax... chunk of Tetrium out of mould cleaned up in router, very little porosity due to vacuum process...

[badhabit]

Another suggestion is to use mylar tape. Packing tape is commonly used for one off moulds where surface finish is not important. A packaging company may have a wide sticky tape that you can apply to the surface. Then a quick wipe with wax and your done... for instance in the photo attached there is no wax involved. The timber has been wrapped with clear packing tape and the melamine has a plastic film on it... this is an epoxy infusion of steel and other fibres.. Mould is dry stacked then use vacuum to pull epoxy resin through the part. You could do this as well but keep going the way you know... That mould has been used 3 times no wax... chunk of Tetrium out of mould cleaned up in router, very little porosity due to vacuum process...

I've done quite a lot of regular infusion projects and i used this sort of tape: https://www.easycomposites.co.uk/flash-release-tape it does not require any wax or anything. Epoxy just don't stick to it. It is actually quite nice tape...

I also considered the "wrap the form"-approach, but it has quite a lot of recesses etc...it is going to be a nightmare to wrap....IF i can find "tape"/wrap wide enough.... "stacking" the tape side-by-side is to tedious for me and will most likely cause stripes in the surface...then i like to odds with the wax better...

/Thomas