You dont want to use polystyrene, you need PVC foam. Various thicknesses and densities are available from a few suppliers in NZ. Nuplex composite supplies, Fibreglass supplies, compostite supplies christchurch, PJ hobbs, the list is endless!
She is not aware of anybody that actually manafactures the stuff in NZ , but most all of the polystyrene companies import it ( her work gets theirs from Germany ) . They have branches in Auckland , Wellington , Blenheim and Christchurch and are usually happy to sell smallish quantities for model making purposes .
( by " smallish " - I mean by the sheet , as opposed to a house lot . Its not particually expensive though )
XPS - Extruded polystyrene is the stuff I was after - thanks Lumpy. Great to see Expol does have it - I thought they only had the expanded stuff. Foreman sells the Dow stuff by the sounds of it - thanks.
PVC would be good but I have read that it is 5x the price of xps. Will follow up those links too.
Hi David, I noticed today a comment that Bunnings are selling extruded Polystyrene foam 1200 X 600 sheets 30mm thick at $15, or $24 for 50 mm. There is actually quite a lot available from various sources around the country. I acquired a good quantity at a much higher strength (80kg/m3) AS2122.1 ex a builder's skip, Goldfoam GF-2, 30mm thick but 1.8m in length and strips about 200mm wide - plus a good quantity of the blue Styrofoam about 40 mm thick at about 1/2 metre squares. Nice to have friends in the building industry! Cheers Colin H