Vibrating Mirrors Permanent solution: Unscrew Mirror from the holding bar, instert a large dollop of bathroom silicone sealer inside the mirror casing, i.e. behind the mirror. Leave to dry = Hey Presto! The rubbery consistency of dried slilicone will dampen the vibration for ever.

You can also use expanding foam but then you need to cut the excess with a stanley knife because that stuff has the tendency to expand 10 times what you "squirt"