Tom.
Thank you for the note.
Yes, PVC has sprung to mind, but the problem is that here in Hong Kong, we have so much sun year round that anything 'plastic' based rots in no time at all.
Except for the magnet discs, my entire turbine bodywork is stainless steel and I am trying to find something that will last 20 years or longer, 50 years would be glorious, and 100 years icing on the cake!
Dave