Refinishing a Hardwood Floor: Is Sanding Necessary?

LESLIE: Joyce in Missouri is on the line with a floor-finishing question. How can we help you?

JOYCE: I do have a question about my hardwood. It’s the old, solid hardwood put down back in the 50s. I love it and I refinished it, oh, probably about 15-17 years ago. And with the time and traffic, the top is wearing now and I need to sand it down and resurface it. When I did it then, I used GYM-SEAL. But I want to know what would be the best product that would be long-term lasting and something that would be user-friendly for an individual.

TOM: OK. So first of all, in terms of the sanding-it-down part, does the floor have any really severe wear or is it just the finish that’s worn?

JOYCE: Just the finish.

TOM: So you don’t have to sand it down all the way. What you can do is you can basically just lightly sand the surface. There is a machine called a U-Sand machine, which is like an abrasive disk sander that you can rent at a home center or a hardware store. It has four abrasive disks in it. It does have a vacuum system built in so it doesn’t leave dust all over the place.

But it won’t wear down the wood too much. It’ll just sort of take that top layer of finish off and get it ready to be refinished. Because with hardwood floors, you don’t want to sand them completely down if you don’t have to, because that takes many years off their life when you take all that finish off down to the raw wood. It’s really not necessary.

And then after you sand it, then you can apply an oil-based polyurethane. So not water-based but oil-based, not acrylic-based but oil-based. And you’re going to apply that with what’s called a “lambswool applicator.” It’s kind of like a mop. And you dip it into a paint tray, you apply it in a very smooth, even coat. Start on one end, work your way out the door and then leave for a good four or five, six hours depending on the weather.

JOYCE: OK. With the windows open?

TOM: Yeah. Yeah. If it’s a nice, dry day and the windows are open, that’s the best thing. But just remember: whatever it says for drying time on the can, at least double it because it tends to be a bit sticky for a while.

JOYCE: OK. So an oil-based polyurethane and a lambswool applicator.

TOM: Yup. And then with a light sanding before you start the whole thing. OK?

JOYCE: Sounds wonderful. Thank you so very much and you all have a wonderful day.