I've been messing about with lost foam aluminium casting here in the UK.
I've tried packing expanded polystyrene, and Jablite but they seem really difficult to get a good finish on the foam patterns. I want to be able to machine them, or use them in a basic foam lathe.
I know that in the States they have a denser finer grained insulation material (blue and pink in colour). These both seem to be better for obtaining surface finish. I've tried to Google the stuff over here but it seems to be silly prices.
Does anyone have any links to UK sites that sell a similar product? I was wondering if the harder stuff that you saw up and stick between the rafters for loft conversions would work as this seems a much denser fine grain foam to me.
Any ideas or advice would be appreciated.