Hardwood Floors October/November 2024

Is it Real Wood? Is it Refinishable?

the dark spots taking away from your craftsmanship efforts. In addition, unlike the test photos, the affected boards likely will be few and far between and spread throughout the floor, making it very difficult and time-consuming to identify them all before sanding. Even if you identify and replace apparent black spot boards, other affected boards may become present in the floor (from the same tree or area) but just not showing their spots until you open up other affected vessels when sanding the floor. It can seem like you’re chasing your tail on this one. As you can see from the test photos, once the floor is sanded (photo 2), the spots are difficult, if not impossible, to see because the dark smudges have been sanded off. The application of white stain (photo 3) didn’t pull them back out but just made the floor look fabulous. However, the black spots returned to the surface within 10 seconds of applying our first coat of waterborne sealer (photo 4). Two additional coats of waterborne finish didn’t make them worse, as the sealer did its job of sealing the floor against further penetration. Still, the final look probably is not what the customer was “expecting” (photo 5). Replace those boards? Sand the floor again? Spots appeared on different boards? Chase your tail? While water-popping did make some of the spots appear (photo 6), it’s not enough that they would make the alarm go off in my head when inspecting the floor before staining. Plus, it still keeps me chasing my tail with pull and replace, sand, other spots appear, round and round we go. So, for the moment, the best thing you can do is to discuss the possibilities of these spots showing up with your customer during the bid process, as it’s much harder to explain these away after the fact. However, through my testing, I think there are a couple of “systems” you could use to prevent or minimize these dark spots. I will cover this in my next article, which will be available on hardwoodfloorsmag.com.

The hard surface maketplace is full of confusion. The NWFA Engineered Wood Flooring Refinishable Program cuts through the clutter and identifies real wood flooring products with wear layers thick enough to be sanded & refinished. LEARN MORE ABOUT THE PROGRAM AND VIEW THE COMPLETE LIST OF CERTIFIED MANUFACTURERS

Todd Schutte is the director of global eLearning for Bona AB in Englewood, Colorado. He may be reached at todd.schutte@bona.com.

SOURCES: Black Spots in Red Oak – 1991 Gerald Thompson (Bona US) and Lidia Brito (Colorado State University) Dark Deposits in the Grain of Red Oak – 1990 Gene Wengert & Fred Lamb (Virginia Tech)

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