My house is almost 100 years old in southeastern IN. The floors are red oak, they were never fully finished.The perimiters were stained, and then area rugs were put down. Rooms are about 15 x 15 and the area rugs were about 10X10. Zero finish under where the rugs used to be. I drum sanded with a 24 grit drum sander for 7 hrs in two rooms and I can still see where the area rugs were. The formerly stained areas look great, but the area rug areas are dark. I now have a very two tone floor, and I have filled a large trash can with dust.

I would love some idea on what to do next. My end goal is some sort of dark stain that is easy to take care of, and will last a while.

Well after looking at this post http://www.hardwoodflooringtalk.com/forum/post35645.html?hilit=red%20oak#p35645 it seems that I have duglas fir.

Still need help

I ain't no expert finisher but I think you should stop until you figure it out. This seems kinda backwards as far as area rugs and the patina of wood floors go. Perhaps it is because there was no finish or stain where the rugs were so that part aged and the stained part was protected. Just a theory.

That sounds like a good theory. Like Fir is soft, and what wasn't covered with carpet has 100 years of impregnation,therefore stains lighter, as compared to the carpet covered area. Are these 2 installers out in left field, sand guys?

So I'm not so sure that it is Fir. It has a lot of red in it, and its not real soft like poplar or anything.

I guess I need to get some pictures.

Cleaning the floors with oxalic acid has been recomended to me. I'd like to know what you all think.

Thanks again

Hard to say without seeing it, but that color difference you are seeing quite possibly goes into that wood 1/4" or more (as far as the nail heads, anyways). Pine, fir, cherry are just a few of the woods that can take on a "non-sand-outable" color change due to UV damage, etc..

If you sanded with a 24 grit, your only hope of trying to hide these areas a bit better may be to stain the floor.

I just sanded a floor that had some stains. I went back and forth atleast 6 times with the 24 grit but couldn't get rid of the stains. They got lighter but are still there. I couldn't sand forever for fear of ending up in the basement.

It is correct that the stain areas were protected and are lighter and it will likely stay that way. This is very common with fir, you can try to mask it with stain but you will not be able to get rid of it, If you keep sanding to far you will end up with a thin wear layer that will splinter as you use the floor.