Floor refinishing, our tryst with the multi head orbital

Sounds dirtier than it is, I promise.

Now, if you are going to refinish a floor, the most obvious part of the process is that you have to get the old finish up (closely tied for "most obvious" with needing to put down new stain"). In the olden days, there was really only one way to do this, a drum sander. But drum sanders have a fairly scary reputation (more on this later). So, for the do it yourselfer, a few years ago there emerged another, safe option:the multi-disc orbital. And after much reading, and researching, we decided this was the way to go, because pretty much everything we read said it was practically foolproof. So, we found a recommended brand, and a place that carried them, and one Saturday morning a few weeks ago, we went and picked on up our very own, which looked like this:

now if you were to tip that puppy back, you'd see that it has four round discs on the bottom. This discs spin around, but the also oscillate in a random pattern so that the scratches don't all appear in the same direction. This is in contrast to the drum sander above, which only sands in line with the direction of the drum. Because of the random oscillation, you kinda can't mess it up. And if it sits in the same place on the floor, well, that't not a problem either. So all signs pointed to this being the machine for us. 

Unfortunately, the place we rented from was pretty busy and the guy that helped us was, and I quote, "not a floor guy" so they were pretty sparse with the help. No manual, no nothing and we had to ask for help. I would not recommend them. But, the machine was supposed to be foolproof, so we went ahead. We bought a ton of packs of round disc paper, lugged the thing home and up the stairs, and decided the back bedroom was the best place to start. 

We have the requisite before picture:

And a during, Matt's sort of buried in the closed here but you can see the pattern we started with:

And after 7 hours of hard work, we were here, sigh:

As you can see from the variegated color still on the floor, we didn't get all the old varnish off. We read in the books that if your floor is in good shape, you can start with 60 grit. We figured, our floors weren't amazing, so we started with 40. And that got us about a 3x6 ft square using one set of pads. So, we changed the pads a bunch, and kept going, because at that point what did we have to lose? But after a lot of time, we basically had to admit defeat. Not only did we not buy nearly enough pads to do the rest of the house, but it would have taken us about two weeks to finish it up, and at more than a dollar per sandpaper pad, and four pads on the machine at a time, it would have cost a fortune. 

But, we did learn a lot. First of all, the machine is foolproof. And very easy to use. You basically just turn in on and it does all the work. Secondly, our floor wasn't in sort of bad shape. It was in BAD shape. You can't really see from the pictures, but we had some major issues with cupping of the floorboards. Cupping (and crowing) occurs when the moisture content above and below the floorboards is different. You can see it really easily in water damaged spots, but we had it all over our floor. Probably because our lower level is a basement. In any case, cupping is when the middle of a board is lower than the edges (crowning is the opposite, where the edges turn down). All of this meant that the random orbital, because it was flat and not very aggressive, couldn't get at the places that were lower. 

Long story short, if your floor is not absolutely flat, you don't want the easy way out. You need the big boy sander. Which is what we did the next weekend.