Q: We sanded and stained and polyurethaned old wood floors. There were really dark spots from old stains on some parts of the floor. We sanded them as much as we could. After we stained the floor, and put on the polyurethane, we now have big white spots on some parts of the floor.
A: Are you sure you removed all the old finish before staining? I try to caution people that this trade is really not for the DIY person. It is simply very difficult physically and technically.