09-17-2024, 08:38 PM
If the "stain" is black rust, it does no harm and best to just leave it.
“Those who think the world began less than 10000 yrs ago are worse than ignorant … deluded to the point of perversity, they are denying not only the facts of biology but those of physics, geology, cosmology, archaeology, history & chemistry.” – R. Dawkins