My painter contractor recently allowed vinyl siding cleaning solution to cover and dry on a bay window's copper roof.
Since then, they have tried to wipe off the dried cleaning solution (didn't work), then use Brasso (didn't work, but added to the discoloring) and have since used some type of paint thinner to remove all their previous blunders.
Now, with the paint thinner the copper plating has turned a grusome, splotchey, all-around yuckey kinds of discoloration; no where near the copper or it's oxidized color that it was.
What can the copper be restored with?
Thanks! My painter is fired!!!