At the same time I did the kitchen, I also did the dining room (2 coats stain, 3-4 coats poly). The dining room is adjacent to the living room which was carpeted at the time. Now the wife wants the carpet out and the floor refinished. Can I refinish just the living room? I am concerned that at the junction of the living room and dining room, I will see a visible transition line. Or should I just put two coats of poly on the living room, then light sand both the living room and dining room and then apply a third coat? The dining room was finished with an oil based poly. Can I use a water based poly for the living room or will there be a noticeably difference?