It’s best to start backward and move to the future of where we are now. Drum sanders became belt sanders, scrapers became palm sanders, dust control became the standard, and hard-plates became multi-disc sanders.
My early years in flooring started with Clarke in 1985 as a service tech. Some of the best knowledge and skills, the real craftsmen of that day, walked into the service center. These guys loved showing me photos (not on a cell phone or tablet) of the beautiful floors they produced. Their tools were a critical part of the work they produced. Everyone was using the same tools and seeking ways to better improve the trade. I recall some of the crews talking with the service techs in the repair shop about ways to set up the sanders to fit their style of sanding. They would always debate about where they cut, how they perform best, and how to take the stress out of hiding the scratch. The leaders of the day and the professionalism they introduced was invaluable to me. Over the years, I began to wonder how a floor could get flatter than what I had seen done with a hard-plate. No way could a crew get rid of imperfections from the big machine or edger without the hard-plate.
The first multi-disc unit I saw was the Trio from Lägler in 1994. The idea of this tool was not to replace the big machine, but to reduce stress on the body, remove imperfections, and reduce the scratch. The driving force of the Trio was to flatten the floor and complement the big machine. Today we have multiple options for multi-disc sanders.
During training classes held by the NWFA and some manufacturers, I have put my hands on many different pieces of equipment. Getting past the old school mindset of using a hard-plate happens fast when you get to look at how nice that last coat of finish looks on the floor that was sanded with multi-disc units.
Every floor sander has a different style, process, trick, and tool that they use to sand the floor. Picking the tool that fits our style and process goes back to how they cut, where they cut, scratch imperfection, and body fatigue (the stuff I learned in my early days in the service center). Features, benefits, scratch, and my all-time favorite question – how does this affect me? At schools, many have heard me say over and over that these tools should not be referred to as floor sanders. These tools are paper turners. The paper does the work and it’s the mineral that cuts.
Features
The multi-disc sanders may use paper sizes from 4” to 8”. Even though the units are all unique and different in their own way, each unit offers the same feature with regards to getting the imperfections such as chatter, wave, and dish-out out of the floor. Hard plates can do this as well, but unlike today’s multi-disc units, they can leave a more-harsh scratch. I see this as the best feature of the multi-disc. It can get a floor flat while it reduces its own scratch at the same time.
The next feature of multi-disc sanders is how they complement the big machine. Yes, I see social media posts of folks doing the total job with just the multi-disc and a jitter-bug (AKA palm sander), but when we have a remodel job with some bad overwood or loose floors, it can take more time to get the floor flat.
One or two cuts with the big machine on angles will speed up the job. It is not uncommon to cut a floor on a 15 to 20 degree with 40 or 50 grit (big machine) to get it flat, then jump to 60 grit (multi disc) to remove the angle cut using a multi-disc sander. The next best feature is we can put the untrained floor mechanic behind the unit. Pushing it like a shopping buggy cannot get any easier for the newest crew member.
Let there be light directed at the floor. This feature offers light with a purpose. Seeing the fine scratch can be a challenge at times, and having scratches exposed with bright LED lights is a must.
Having choices with power is great as well. In some of the older homes I have worked in, they still have screw-in fuses, and getting 220 is a battle. The 115/120 volt units give guys an option when dropping a 220 volt line is otherwise impossible. (The 115/120 volt units do require a “clean” line to prevent popping breakers or fuses.) These units are not as heavy and one person can tote them in and out of the home. They cut flat, scratch less, and floors look amazing once finished.
Be sure to take advantage of the NWFA training classes. They held their first sold out multi-disc class last year in Tennessee, with four different brands of multi-disc units. Running them side by side and getting hands on with the instructors was awesome.
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 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 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.
