Hardwood Floors April/May 2025

AT THE SITE Multi-Head Sanders: What You Need to Know (Continued)

The friction drive units have a two degree pitch to the drive disc. The main head spins counterclockwise, making the drivers spin clockwise. The units like this have more pressure on the outer edge of the pads. They flex a small bit and are aggressive. They flatten fast with a smaller footprint. Some units have six discs and some have five discs. The 5-disc unit will cut faster and a flatter than the 6-disc units. The scratch is easy to hide when using

BENEFITS The biggest and most important benefit of using multi-disc units is the final look of the floor. There’s just something about how the floor looks flat, and scratch-free, giving it that wow factor. Zero wave, zero chatter, zero

dish-out, zero drum marks, refined scratch, and giving the perfect surface that lets the finish lay right on the floor, like it was meant to be. Multi-direction floors, mixed species, flat sawn floors, wide boards, floating floors, engineered flooring, and custom installs fall right into the benefits of when and where to use multi-disc machines. The multi-disc units also can be used on factory finished floors. With diamond drivers, we are able to cut through the finish quickly while saving money on high performance sandpaper. Once the finish is cut off, we can move forward with the big machine to remove any micro bevel or over-wood. Once more, the multi-disc is complementing the big machine while saving time, money, and body fatigue. SCRATCH Every machine has a cutting point and a footprint. While it seems like it would not matter how we travel across the flooring with these units, that is far from true. The multi-disc units that work like the buffer still move right to left and up and down with handles. The multi-disc units we can move around like a shopping buggy have slight slope. The main heads rotate opposite the disc on almost all units. I have seen a few that rotate in the same direction as the main head and that can change the way the unit cuts. The most important factor is they all drive paper and that paper will leave a footprint. First, the size of the paper matters. Four-inch paper almost always is not round but has a flower shape. This helps with the clean-up of its own scratch. If it hits a void, then hits the void again, it helps to reduce its own scratch much like inter-coat pads and sandpaper. It cuts, cleans, cuts, and cleans while we are using the cutting point on the machine.

the correct grit sequence with either of these types of units. Most folks water pop so the “angel hair scratch” hides when stain hits the floor. The 7” and 8” units cut flat and are planetary driven with a belt, gears, or chain and can be bigger and heavier. The extra weight and size does change the footprint to a much wider base and cut. They do leave a longer scratch due to the size of the paper. Get down on the floor with a bright LED beam and look at how each unit cuts, cleans, and leaves a scratch. Is one better than the other? Asking a few manufacturers’ reps, they will all tell you that theirs is the best, fastest, and hides the scratch. Ask me and it’s all about your style, needs, and how they can complement your sanding jobs. Like the guys back in the service branch, we all find a different road to the final coat. This affects me when I see the last coat of finish. The flat floors looks amazing! I do not have to spend more time reducing the scratch. The reduction of stress on the body is huge and having the ability to control the speed on the unit aids with the paper’s life. Training a new floor mechanic is easy and fast. It brings all of us up to the next level. Multi-disc sanders are here to stay. They have changed the rules for how well a floor can be sanded. I would encourage everyone to attend NWFA classes that offer the multi-disc units. Research the best unit that fits your style. Reach out to your distributor and ask for an on-site demo. You will see the wow as you get the finish on the floor. Wayne Lee is business development and technical advisor for Middle TN Lumber in Burns, Tennessee. He can be reached at wlee@midtnlumber.com.

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