Global Scale Modeller

I'm looking to start my first diorama which will be a concrete bunker built into a hillside.

I'm casting the concrete building using plaster of Paris and using modroc and mesh etc on the hillside and rock faces. I went to the shed to start making up moulds to start the exterior bunker walls but did not have any sheets of ply to use as shuttering / moulds.

I did however have loads of sheet styrene so decided to use that instead. The moulds will be sacrificial due to the shape if the casts so will need to be broken out once the casts dry.

My question is ...... will the plaster stick to the styrene ? If so, what can I use as a release agent ?

Any advice would be appreciated. If all else fails I could make up a test mould and see what happens but if anyone has tried it and knows the results ....... why invent the wheel again.

Cheers

Toto

No idea mate...gotta test it out

No worries .... cheers anyway

I suspect it will stick due to the sometimes uneven cells of polystyrene.
Petroleum jelly perhaps or anything like that that will repel water, but as Scott says test a small piece first.