Rubber and paint

[ppppenguin]

It's a bit of a mug's game trying to predict interactions between polymers, paints etc. We know that PVC and polystyrene aren't happy neighbours. Also that natural rubber (non-vulcanised) will be badly damaged by hydrocarbons. Silicone rubbers are pretty inert, until they meet silicone oils.

Polythene is pretty safe with most plastics and finishes.Could you somehow slip a thin sheet between the eye and the dial?