Removing paint from wood floors

[Daniel Porter]

So I tore up some carpets in this house and found some wood flooring underneath that seems pretty salvageable. Whoever rehabbed it before us was really sloppy with their paint job and left paint all over the floor, and actual coats of it near the trim. Is it possible to remove this with some sanding? Maybe a 20-30grit? I’d love to get these floors back in action! I’m planning on doing a dark stain to help hide some blemishes, but the paint is a big issue.

[Jim K.]

Originally posted by @Daniel Hennek:

Sounds like some YouTube can help you out. You're getting answers all over the place and some of them not good at all. There are lots of ways to refinish a wood floor and it sounds like your going to need to do the whole thing and not just where the paint is.  Watch a few videos.

Well, it's not exactly a cacophony. And it turns out that this is a great opportunity to illustrate something interesting about DIY. Why are there multiple answers to the same question, and why do they sometimes conflict?

Here are some of the people talking about this here: I'm a handyman working in my own old, beaten-up C'class properties in western Pennsylvania. @Matt Clark is (please correct me if I'm wrong, Matt) a high-volume property manager who has been in this for over a decade and also worked as a handyman before he stopped. @Mike Reynolds is (please correct me if I'm wrong, Mike), a GC who had filled multiple roles on teams working in new construction and renovation for decades. I don't know @Account Closed , but judging from the posts I've read, he's also a hands-on landlord with clear experience working on his own properties himself in the past. I don't know @Frank Scaffidi at all, but he's giving a good answer here. All of us have different takes on the problem.

Denatured alcohol softens latex paint, turns it into a putty. So does TSP, but not as effectively. What TSP also does is work on heavily soiled areas, including residues of old oil-based paint. The newest property I own is over 45 years old. Even getting my start in Athens, Greece, I worked in poured-concrete masonry apartment buildings. I use oil-based primers and paints on a lot of problem surfaces much more frequently than people working in newer construction. So when I see a paint stain on a floor, I tend to reach for what I know as a general paint cleaner, TSP. When Frank see it, he reaches for acetone (nail polish remover), which is also a strong general solvent, or rubbing alcohol, isopropanol, a less powerful but still highly effective solvent and cleaner.

I talked about green scouring pads, Kris talked about Scotch-Brite. They're the same thing.

I said "a small scraper" because I actually meant a 3/4 in. putty knife, a little guy you can get a lot of pressure behind. Since I'm using TSP, the paint will tend to come off in flakes, not turn into soup. Kris, using alcohol, warns against that. Kris talks about keeping the rubbery putty softened by denatured alchohol out of gaps in the flooring if you use a putty knife.

Mike goes deeper into denatured alcohol, the green and the clear. The green works better as a cleaner. He doesn't know why. Because I was on my high school's trivia team and still enthusiastically collect useless facts, I DO know why. An increased amount of methyl (wood) alcohol, a more powerful solvent than ethanol, is mixed into green alcohol to denature it. If you drink green denatured alcohol, you'll go blind. What's mixed into clear denatured alcohol to denature it is mostly concentrated ipecac extract, stuff to make it stink and taste very bad. This is typically why it takes a much higher dosage of clear denatured alcohol to suffer permanent negative health effects, and you'll be vomiting faster ingesting a similar amount of clear versus green alcohol (kids, don't try this at home!). BTW, in the USA, it's green. In other countries, it's a different color. Greece's is blue, Italy's is pink. Clear is 97% ethanol, colored is 92% ethanol.

The OP got different answers about sanding, too. All my hardwood floors are either 90-year-old+ heartwood pine or white oak. I refinish for utility, not for appearance. I would be going with coarser grades. Mike gives a more measured answer, with finer grades.So does Frank, who also refers to refinishing the whole floor.

Matt posted a link to a coarser paint stripping wheel that only goes on a drill, they make others that go on a grinder, and they're easily confused looking at product pages on a website. These are essentially very beefed up scouring pads. It's faster grinding out paint by machine than doing it by hand, and you can do larger areas without solvent. A grinder is faster and easier to use to do this work than a drill. That is probably the better solution to reach for in areas and situation where you have to avoid spreading stink and get the work done soonest, such as apartment buildings. It might not be as good in tight corners and tight along floor edges, where you often get the kind of drips the OP is talking about.

We're all different. with different ways of coming at the same problem that have worked for us in the past, and in my case, I will almost always give you an answer based on not-so-nice working conditions in old single-family properties that will get you to a good-enough solution. If you have an A-class or a B-class property that you're trying to DIY, much of my advice is a bit rough. Mike has worked much more than I have in different conditions, places where you might be dealing with softer wood flooring materials that can't take the same amount of abuse as a white oak floor that's survived 80, 90 years of being walked on.

What about you, Daniel? What's your experience doing this work?