The "green powder" is verdigris,
The "green powder" is verdigris, and is quite common on old/neglected/exposed to the weather, electrical contacts. Glad it was a simple fix
Quote from: robbo on 19 May 2021, 10:03:56 amThe "green powder" is verdigris, I thought that was the stuff worth £1.000's that dog walkers find on the beach that comes from whales and used in perfume.