Underneath the carpet are many stains. I am sure they are stains from dog urine. Can they be sanded away? Or is my only option to replace the boards? If so, I will have to forget refinishing and just put carpet down on it. I really want to refinish these old, old floors. But I won't try it if it is not going to work. I sure don't want the spots to show through.

Start sanding, and then you will know. A sanding block, with 60 grit will work, to let you know if it is carpet time.

Pet urine is bad news ... a sanding block may not get deep enough to tell you for sure. Any chance you may be interrested in staining your floor very dark? Could do a decent disguise job.

Well, you made me feel a little better. I don't know if my husband is up for all that sanding. But I know it would add value to the house, if it worked. These are truly horrible stains. Large and all around the space where the bed was in the masterbedroom. The finish is gone where the stains are. So I will just have to see what he says. Wish me well.

Inez

I believe that you have 2 options.. staining DARK... or carpet.... you have to accept the fact that you will see darker spots..possible your friends may not.... Replace furniture strategically.. large area rugs??..... either way, lower your expectations a bit. It can come out decent. Good luck.
If its done already, what did you do?

I have been doing some reading and have found that people have used hydrogen peroxide to bleach the stains and then they have to re-stain it and have had good results. As for odor is seems white vinegar works well.

I have found this from this site http://www.ehow.com/tips_2700.html

For odors the ONLY thing that I have found to work are products that use natural enzymes. They break down the protiens that cause the odors. You can get them from pet supply stores. A good brand is Natures Miracle.

I think we are going to put carpet in the house. But I do want to at least try to sand and stain and polyurethane the dinign room. Thanks so much for all your tips and advice. I had not thought of the odor. The house is so dark and the floors look so stained up I had not even thought of the odor lingering after cleaning. Thanks for the website.

Inez

once you stain and poly.. there will be no odor. If you are going to put carpet down and worried about the stain. ... Hit it with a coat of Kilz oil based.

We are going to sand off the old finish and stain and polyurethane the wood floors. Now our question is: Should we buy or rent a sander? We live 50 miles from a rental place. How many days will we need the sander? What sort of sander should we rent or buy? First step is to take down the facings and mop boards. We are also removing the paneling which was installed over the sheetrock. So we have plenty to keep us busy for a few days. We are retired so we have more time than we have strenght. Would we be better off to hire someone to do the sanding?

Yes... you are better off hiring someone.. This is not a job for a diyer... it takes years to master and did you say you were retired.. Im assuming you are over 60.. This is VERY LABOR INTENSIVE...Alot of bending over... Im 34 have been doing it for about 6 year and trust me.. this is not something you want to try.. If its done wrong.. it can cost you alot of extra money that you would have saved. You are also staining dark.. which is one of the most difficult floors to accomplish. Get 3 estimates.. Talk to each persons last 3 jobs that completed.. and ask lots of questions. Good Luck..