Hardwood Floors June/July 2025

AT THE SITE Minimizing the Dark Spots (Continued)

If you have a customer who wants their floor stained white or natural, let them know that these spots might make an appearance somewhere on their floor and that while you’ll do your best to minimize any reactions, it’s considered a natural part of their wood floor (i.e., character).

DEALING WITH CUSTOMER EXPECTATIONS

HOW CAN YOU MINIMIZE THESE SPOTS?

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Water-Pop the Floor During Sanding – Because we know that the life-form deposits that cause these black spots are water-soluble, water-popping a new install or water-popping after the first cut on a resand should bring any potential spots to light. You also might want to spot-pop problem boards/ areas between every cut. Because there is only x-amount of the dark spot material within each cell, the more you can bring out and sand off with each cut, the more significantly you will minimize any residual material from being drawn out once the stain, sealer, and finishing process starts. Also, remember that with successive cuts you may open up other cells that contain the blackish material, creating other spotted areas, though usually on the same boards. Apply “Thin” Coats of Waterborne Sealer – We usually don’t push the “thin to win” theory when applying any sealer, as a proper coat at 500 square feet per gallon is already thin enough (about 1/1000” = one sheet of copy paper), but in this case, thinner coats will give you better results as you battle to minimize the devious spots. Again, due to the greater water solubility of the dark deposits, if you can reduce their exposure to water, you’ll get less pull, and the resulting initial sealer film will help to minimize any additional pull from succeeding coats; though you might have to apply two to three thin coats of sealer to give you the desired build you want prior to your finish application. Spot touch-up with game line paint – Depending on the final look and color that your customer is expecting, any spots that are too dark (or snuck up in an unexpected area) after the sealer coats have been applied can be touched up with waterborne game line paint. You’ll have to work up the blend that works best for each floor’s final color, with light beige being a great place to start, then adding white or yellow/brown to take the color in the desired direction. As the spots tend to originate and spread from the soft grain vessels, touch them up with your paint blend like you would a stain repair, dabbing on the paint and feathering it out in the same direction as the grain/spot pattern with an artist’s brush. Good feathering is the key to making it look natural (as is a good color match).

PHOTO COURTESY OF BONA

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