Originally Posted by Surreybirder
The link quoted in the message is:
though I don't think that's the full story.
Is Polycarbonate the stuff they sell in sheets at Homebase? It seems to come in various grades (thicknesses). I wasn't sure 'cos it says 'keep away from heat' on it.
The transparent cone on a Robinson never even gets warm,i think it must be because the inner cone(usually sprayed silver) is between it and the bulb.