This is the second time I have used Roebic Brand sulphuric acid drain
The first time in the bathtub, I didn't cover the drain, when I returned to
the bathtub, it was covered with a rust color stain. It did cleanoff with
time and considerable elbow grease.
Now I have done it again! This time I covered the drain so the gases would
cause the stain again. It didn't work, I still have the rusty stain in the
So what is the stain, and what is the easy was to clean it off.