Hardwood Floors June/July 2025

reported back that after a year, the black spots had faded to an almost indistinguishable level – only noticeable on hands and knees if you knew what you were looking for. He also clued me into the game line paint method. So, this time element also is something to keep in mind while discussing expectations with your customers or trying to figure out the best way forward if they do pop up. It’s always a heartbreaker to hear someone resanding a floor to try and resolve an issue like this, unnecessarily taking away from the lifespan of the floor when a little bit of time (and paint) might be all that’s needed to fix the problem and get everyone back to loving their hardwood floor.

Achieve the white color with sealer instead of stain – The application of white stain is not enough to seal the dark deposits into the vessels, and they typically are not visible once the floor has been sanded, so staining a red oak floor white may be a waste as any residual dark spots still will pull up through the stain. A better route would be to apply thin coats of white pigmented sealer until the desired level of white is attained, which also will minimize the deposits from coming out as described above. Then, touch up any spots, as needed, with your paint blend and apply clear coats of waterborne finish over the top to protect it all. While a solvent-based sealer would be more effective at preventing the black spot material from leaching back up to the surface, they will all turn the wood surface too yellow (even worse over time) to fulfill a white or natural look floor, as seen in photo B1 (natural, opposite page) and photo B2 (white stain, opposite page) that were both sealed with two coats of dewaxed shellac (OMU would be even darker and yellower); thus, our sticking to an all waterborne system when trying to troubleshoot this issue. Give it time – A friend and great craftsman from the Williamsburg, Virginia, area, who first alerted me to the resurfacing of these mysterious black spots occurring on red oak while he was working on a historic museum job also 3 WHY NOT USE SOLVENT-BASED SEALERS?

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

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