Im pretty sure that they are stains from animals, but they were here LONG before we purchased the hosue so theres no way for me to be certain. But I will try a few different solvents before I give the go ahead for sanding..
I have recently rented the large drum sander and tripped my hardwood floors of the top finishes. I ran into a slight problem though. There are significantly dark stains in the high traffic areas of the floor. I tried to sand down below them but I am afraid of sanding too much and having a...