Hello,

My home has a small section of pine floors that have pine floors that need to be refinished. It does not appear as if they are currently stained or polyed. In the picture you can see the unstaoned section next to what is stained.

How much will this need to be sanded since there is nothing on it? How do I know when to stop? Also, what type of sander should o use? After I sand and clean the floor, how many coats of stain should I expect to apply? How many coats of poly?

Thanks for the help!

Pine floors are pretty soft so they will sand easily. Even if you have a fairly large room I think that a 6" random orbit sander with 80 grit sandpaper will be your best option, unless you know how to use a belt sander. Only sand the floor to smooth the planks so there are no edges that you can feel between the boards and remove the mill marks, which may show as small ridges if you look closely.Scrape and hand sand the corners with 100 grit paper, folded into thirds. Keep the scraper sharp with a mill file so you don't need to work too hard, and get some knee pads. Practice the stain color on a loose piece of pine to get the color to match. When the stain is wet, that will be the color after it has dried, been buffed, vacuumed, and the first coat of finish has been applied. I like to give the stain 24 hours so that the oil can harden after the paint thinner has dried. After the first coat has dried, when you lightly sand the surface with fine, maybe 100 grit paper, and the surface powders, you will be ready for the final coat. If you want to apply a third coat, wait a couple of days, then buff with fine sandpaper vacuum, or tack with a damp cloth and apply the finish. I use gloss for the first coat(s), then satin for the final coat, using up any left over gloss with the satin. Left over finish will skin over and not be usable after a few months, if you have a partial can.

Thank you for the feedback. A few follow up questions:

This is an old wide plank pine floor. There are some large gaps between some of the planks, and some unevenness between them. Is this okay and does it require and special handling?

How many coats of poly do you apply? Two? Or more?

The area I am doing combined is a hallway about 10'X4' and a small bedroom about 7'x 13'.

If you have an old floor, you are most likely dealing with the "finished floor" and the "sub-floor" as one, no sub-floor like modern houses. Unless you would like to re-inforce the floor with blocking between the floor joists installed under the floor, you will have too much deflection for regular wood patch to stay in place over time. You could fill the gaps, but the filler is most likely to crack and come out in the future. If you use a putty that is made to stay soft over time you will have a better look. This putty will be pushed into the gap between coats of finish so the floor looks nice after the final coat.
A stain and two coats would be good for normal wear. In a dining room or kitchen I recommend three coats. This makes the floor smoother and easier to clean and will hold up longer with more traffic.