Hello. I'm remodeling my bathroom. One of the things I'm doing is reglazing the tub. While I was removing the caulk from the sides of the bathtub, I noticed 1 corner was covered in black. I figured it was mold so I poured bleach in that area and left it alone for 1 day. The following day as I continued cleaning, I cleaned up the black stuff and it looks like Charcoal. Can anyone tell me what this is? Maybe it really is charcoal and some people use this to control moisture. Thanks for your help.
Charcoal like Substance under caulking of Bathtub
Oct 22, 2003
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