6

Very closely related: How should I sand before the final coat of polyurethane?

However, I'm not asking for a how-to or which is the preferred tool/method but rather one specific tool and if it's an "ok" approach to take.

Assuming I already owned a 5" random orbital sander (similar to below example image), would it be realistic to use it with 220+ grit sandpaper rather than a "full-fledged" floor buffer, at least to the level where I can use it between a few coats of poly and still achieve a good finish on the final coat?
I'm not really asking if it's necessarily practical, but more as a cost saver while also being able to achieve a decent result (plus I don't have the level of experience with the larger equipment as I'd like/be comfortable with).

From what I've been reading, poly doesn't seem to need a whole lot of intense sanding between layers and just a little roughing up for subsequent layers (by all means correct my if I'm wrong here - would rather be berated online than ruin a perfectly good floor).

I know it'll take longer simply due to size, but I'm only looking at a couple hundred square feet anyway, nothing overly large.
random orbital sander

7

You could use a hand-held orbital- like you mentioned the biggest downside is time. But you're correct, sanding between coats of poly isn't stripping an old floor- it's just scuffing up the previous coat of poly in preparation for the next one.

Even easier for this step though would probably be a pole sander- like the kind for drywall seams. Use a fine grit paper and run it over the whole floor- you don't need much pressure.

  • 3
    Besides time, another downside to random orbit sanders is, all the vibration right in the palm of your hand. Sanding a few hundred square feet with a random orbit sander might be enough to make your hands go numb. – dwizum Jul 8 at 20:16
  • 2
    The linked related question also suggests a pole sander. I'd be worried about the electric sander being too aggressive, plus you have to be down on your hands and knees. – JPhi1618 Jul 8 at 20:18
  • 1
    Yeah, I just went out an bought a pole sander.. After the poly dried I just looked at it, then over at my orbital and though "well, that would just be ridiculous." – Broots Waymb Jul 11 at 20:54
7

I had two floors to do once and between coats I used a broom with 3 bits of fine sanding paper taped to the broom head - cheap, cheerful and effective...

Also, had to punch down the floor brads (nails) so they were below the surface...

Those floors came up magic but also vacuumed after sanding to remove the dust...

  • Was this a "push" broom? – Jim Stewart Jul 8 at 21:33
  • @JimStewart simple broom, soft bristles and a handle... – Solar Mike Jul 8 at 21:35
  • I've also found that lightly "wiping" with a sheet of sand paper wrapped around the hand worked for about 70 m² (with a 2nd wiping with moist cloth & scrubber to remove the dust). Next time, I'll probably put the sand paper around a flat mop. +1! – cbeleites Jul 9 at 12:17
  • 1
    New product idea: Swiffer Sander/Finisher™ - Sands. Picks up dust. Applies urethane all in one step. Main competitor: iRobot Saanda™. – Dennis Williamson Jul 9 at 19:47
1

That is fine. All you're trying to do is knock down petrified fluff and dust. And also scuff the surface to give it some "tooth" for the next coat to bite in to, but that is not necessary if you've hit your re-coat times.

As such, you do not want a tool meant to level; that would mean blowing through the coating entirely on high spots. A flexible, follow the contours tool is appropriate.

1

Best thing to use is steel wool on pole sander. Harper has a good point you are not leveling, but beyond that most sand papers from home improvement stores are to heavy of a grit. Besides it is VERY difficult to clean up all of the sanding grit prior to the next coat. Steel wool and a good cleaning prior to the next coat will give you a mirror finish.

1

I did exactly what you're suggesting a couple years ago on ~500 sq ft of hardwood floor, with great results. As long as you have a semi-decent sander (connected to a vacuum) and decent sandpaper that doesn't clog all the time, you'll be done in no time. In fact, you need to be careful not to spend any time on a single spot or you'll sand right through the whole poly layer. Perhaps a second or two per square foot was about right in my case.

1

You could, but I wouldn't. It's just going to be a lot of tiring work (the sander is moderately heavy, at least for moving it around while sitting or kneeling on a floor you're working on) and possibly take off more material than you want if you're not careful. When I finished wood floors, I just used large-size sanding sponges (very light) and a few passes back and forth by hand. Other answers have remarked that you could do the same with sandpaper (or a sponge) on the end of a broom/pole of some sort, and that sounds even better still.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.