Please help me refinish my wood floors!

[Joshin]

The story: Sunday night the mister got bored, and started ripping up the carpet from the dining/living room. We'd been talking about it for five years, so it was time to act.

Our house was built in the mid-40's. The floor beneath the carpet is in excellent condition -- satin smooth, no major points of damage, no thick layers of carpet glue. We assume it's been under carpet for at least 40 years, from the vestiges of avocado green and maroon shag we found still attached to some of the nail strips.

The issues: Some sort of glue was used. It was still slightly tacky when we pulled up the carpet. Wiped off with a damp rag and minimal elbow grease. Left behind a slightly dark stain where ever it was drizzled. Maybe a shade or two darker than the wood.

There doesn't appear to be any type of finish on the floor. All-natural wood. Water doesn't bead up on it, so if it was treated with a natural oil or surface wax at some point, it's long gone. For all we know, it's always been under carpet.

The questions: Every "tutorial" I'm finding seems to assume that we need to sand off an old layer of poly or shellac to get to the wood for refinishing. I know we'll likely need to sand to get rid of the glue stains (fingers crossed they are just on the surface). We have no experience with this sort of DIY, but we aren't noobs to DIY in general. The questions:

1. What sanding pads do we need for just a surface sanding on otherwise good, unsealed wood? I'm assuming we don't need to start at the same point as someone pulling off old poly.

2. Options if those weird glue stains are more than skin deep? I'm guessing stain/poly finish would just make them look darker and really stand out, but I don't really know. Would also prefer not to stain the wood, and to keep it it's natural color.

3. What's the best finish option that will allow light foot traffic within 12-16 hours? One section must be crossed to access the bulk of the house (including the only currently working toilet). We can stay out of the house for the day, but any longer isn't possible.

TIA for any advice!

[Spork]

I'm at the tail end of an overly long wood floor project.  (I did lots of things to make this take way longer than it should... some of them mistakes, some of them intentional challenges.)

From my limited experience and research, the most common mistake is under-sanding.   I started mine with 20-grit (the most coarse I could find locally) and it was NOT ENOUGH.  (Granted: My floors were very uneven and had THICK poly... this may not be true for you, but keep the "more is better" in the back of your mind.)

For sanding: if you can get away with the random orbit machine, that is what I would do.  Commercial drum sanders are superior (in the right hands).  Rental drum sanders just are not heavy enough.  This is not 240v vs 120v as some people will claim.  It is weight.  The rental sander is likely to bounce around due to it's lighter weight.  Trust me.  I could go into great detail here.  ;)   I would err on the side of more sanding rather than less.   Otherwise, you may end up finishing it and starting over with EVEN COARSER sandpaper.

For finish I used Rubio Monocoat.  Like everything, it has plusses/minuses.
Pros:
* zero VOC.  Many modern finishes are pretty toxic and you're going to have to leave the house for days.  This is made of food grade linseed oil and (I think) smells kinda good.
* it is repairable.   You have a spot that gets damaged?  Sand it, blend it in, done.
* very DIY friendly
* if you get the 2-part coat, you can put furniture on it in 2 or 3 days.  You can walk on it immediately (even while you're applying it.)

Cons:
* you can't go back and put a little more stain on it to darken it if you are unhappy.  It is a chemical reaction with the wood.  Once it dries, you are somewhat stuck.  (You can somewhat lighten it... but you cannot darken it.)
* it is pricey... or at least, it seems that way.  When you realize you are putting on ONE coat that is stain and finish, it is probably about the same price.

Maybe Pro/Maybe Con (depending on your opinion):
* you see the wood grain.  The floor will have some depth to it.  It WILL NOT be the super smooth glossy finish you see most places.  Instead it will sort of look like an old worn floor.
* Know what species you have.  Some species take stain unevenly.  I had this issue (maple) and have futzed with it for weeks trying to even it out.

[TrulyStashin]

I did this last year, chronicled here with pics:  http://forum.mrmoneymustache.com/share-your-badassity/what-i-did-this-past-weekend-refinished-my-wood-floors!/msg361926/#msg361926  There are some other threads on this, too.

Given your situation, with no finish to strip off, I'd use the orbital type sander like you see in my post.  If you can run a vacuum, you can run one of those (only heavier) because they float over the floor.  You may also be able to get by with a light screening ("buff and recoat") if you're willing to stain the floor to match the glue stain. 

I recommend doing a spot sand with a hand sander to determine how deep the glue stain is.  You can sand a bit, wipe it down, inspect, sand more if needed.  If you do that for a while and the stain is still there, you may have to stain the whole floor to try and match it.  Again, if it came to this, I'd do a test patch to see if you can get the glue stain and the intentional stain to match.

[Joshin]

Thanks!

TrulyStashin -- thank you for the info on the orbital sander. The guys at our neighborhood hardware store recommended the drum sander. Now after reading your thread and doing some research, I'm glad I asked on here. The mister is pulling up the last of the nailing strips today, so I'm going to break out the small sander and test the glue (under the dining table, where there will most likely always be a rug just in case I screw up).

We're pretty sure it was white oak, it seems to be the standard in other homes in our area that were built at the same time. Of course, I can't really compare, because all of our neighbors have thrown crazy dark stains on the floors, and we want to keep the natural wood color if possible.

These glue stains just plain piss me off. You can't see them at all if you're looking into the room from, say, the kitchen. You have to be standing right in the room to see them and then BAM! Obvious and ugly.

[Spork]

In theory... the drum sanders really are a better choice -- especially for an older floor.  That wood gets harder as it ages.  The issue here is that the lightweight rental sanders bounce all over the place.  It is extremely easy to get chatter marks.

I noticed my chatter while still at the 20 grit stage and switched to a random orbit machine.  But I switched after things were level.  I didn't remove all the chatter, but I knocked it back (and didn't make it worse.)

I would certainly try the random orbit first, especially since it sounds like you are starting out level and don't have a poly layer to remove.

[Joshin]

The test sanding patch went exceptionally well! The glue stains scuffed right off with two passes.

Spork, thanks for the advice on the sander. I think we'll hazard the orbital sander, mainly because we aren't using stain. It's my understanding that sanding issues are more likely to show up if you stain the floors a different color. Since the glue looks like it will come right up, there's no need to anything more than seal it.

At this point, anything is better than super the cheap white (!) carpet that was in here. It was barely white when we moved in, and after several years with two boys, cats, and a dog, it had developed a rainbow of stains. Fortunately, nothing that soaked down into the wood, though.

[TrulyStashin]

That's great news! 

My house was built in 1963 and I have oak floors.  The results I got with the random orbit sander and a clear sealer are absolutely wonderful.  I bet you get beautiful floors when you're finished too.