I’ve noticed that my metal shower-curtain rods tend to accumulate a layer of blackish or greyish “rust”. Either that, or it may be mildew. It comes off easily and leaves grey or black smudges on my hand when I rub the bar.
Any ideas what metal(s) produces rust like this?
Answer by Randy Chan
If it’s black dust, it just might be metal dust, instead of “rust”. Aluminum is often times used, but it can be almost anything, depending on the alloy used in the rod and their relative hardness. Being that it rubs off, I’d say that it’s metal dust. I’d be able to say more, only if I knew what metals they were.