Bona FlexiSand DCS Buffer: Discs, Screens, Grit Sequence

The Bona FlexiSand DCS is a 16-inch buffer designed for screen-and-recoat work, between-coats sanding, and — with the Power Drive accessory plate — random-orbital sanding down to bare wood. It takes 16-inch screens and pads on the standard driver, six 5-inch discs on the MultiDisc plate, and a quad-head sanding system on the Power Drive. This guide covers the abrasive sizes, the grit sequence for each application, quantity planning, and how the FlexiSand fits alongside drum sanders like the Silverline SL-8 and Clarke EZ-8.

Bona FlexiSand DCS Specifications

Specification	Detail
Motor	1.5 HP, dual capacitor
Power	115V / 15 amp / 60 Hz
Pad RPM	175 RPM
Pad capacity (standard driver)	16 inches — accepts 16" screens and pads
Weight	102 lb (with pad driver)
Gearbox	10:1, all-steel, sealed and lubricated
Power cord	25 ft, 14/3 gauge
Handle	Hydraulically adjustable height; foldable for transport
Dust collection	Integrated dust channel + floating dust skirt; pairs with Bona DCS vacuum systems

Specs verified against Bona’s published technical data sheet for the FlexiSand DCS Buffer (US 115V model). The European FlexiSand 1.9 (230V, 1.9 kW) is a different machine — confirm voltage before ordering parts internationally.

Why the FlexiSand Matters to Floor Refinishers

A drum sander cuts. A buffer blends. The FlexiSand is the second machine — the one that erases drum-pattern scratches, prepares the floor for finish, scuffs an existing coating for a recoat, and (with the Power Drive accessory) doubles as a swirl-free random-orbital sander.

Skip the buffer step and you get drum-pattern ghosting under finish. Most refinishing complaints — “I can see lines under the poly when the light hits it right” — trace back to a missing or rushed buffer pass. The 175 RPM pad speed on the FlexiSand is fast enough to blend the field with the edged perimeter and slow enough not to burnish the wood closed before stain.

The DCS variant ships with an integrated dust shroud and pairs with Bona’s DCS vacuum line for near-dust-free operation. That matters on occupied homes and on dust-sensitive species like white oak where airborne tannin dust stains adjacent surfaces.

FlexiSand Abrasive Sizes — Three Drive Systems

The FlexiSand chassis accepts three different drive plates. Each takes a different abrasive size and fits a different stage of the job.

Standard 16-inch pad driver (ships with the machine)

This is the default plate — a single 16-inch hook-and-loop driver. Use it for:

• 16-inch sanding screens in 60, 80, 100, 120, 150, 180, and 220 grit. Silicon carbide is the standard abrasive for screens. Use these for screen-and-recoat, between-coats poly, and the final blending pass after a drum sander.
• Maroon, red, white, and tan buffing pads for waxing, polishing, and final dust knock-down before finish coat.
• Tampico brush for grain-cleaning hard-to-reach pattern floors.

MultiDisc plate (sold separately)

The MultiDisc holds six 5-inch hook-and-loop discs that spin independently of each other on a planetary drive. The independent rotation cancels out swirl marks that a single 16-inch screen would leave on softer or figured woods.

Use the MultiDisc for:

• Final fine-sanding passes (80, 100, 120 grit mesh) before stain or finish
• Floors with figured grain (tiger maple, quartersawn oak) where rotary swirl would telegraph
• Light cuts on engineered floors with thin wear layers — the planetary motion is gentler

Power Drive plate (sold separately)

The Power Drive is the accessory that converts the FlexiSand from a buffer into a sander. It is a quad-head gear-drive that delivers random-orbital sanding to bare wood while reaching within 1-1/2 inches of walls — much closer than a drum sander, which dramatically reduces edger work.

Power Drive uses:

• Buffer plate — 16-inch hook-and-loop for screens (same as standard driver)
• Multi-disc — four to six 6-inch discs (spec varies by model year)
• Diamond discs — for concrete, terrazzo, and other hard-substrate prep
• Wire brush kit — hook-and-loop wire brushes for textured/wire-brushed finish looks
• Steel plate, Tynex brushes, dust skirts, and 15-lb weight kits for aggressive cuts

Bona’s recommended sequence for the Power Drive on bare wood starts at 40 to 60 grit with the weight kit installed for cutting power, progresses through 80 to 100 grit (weights removed — the lighter touch prevents motor overload on fine grits), and finishes with fine mesh for swirl-free preparation.

Important operating note: when sanding bare wood with the Power Drive, keep the handle as close to 90 degrees vertical as possible. Tilting the handle changes weight distribution and produces uneven cuts — a habit that drum-sander operators have to unlearn when they first switch to the Power Drive.

Grit Sequence for Each FlexiSand Application

Screen-and-recoat (existing finish, no bare wood exposed)

The standard NWFA-aligned screen-and-recoat sequence on the FlexiSand:

Pass	Grit	Purpose
1	120-grit 16" screen	Scuff existing finish for adhesion
2	150-grit 16" screen	Refine 120 lines, even the texture
3 (optional)	220-grit 16" screen	Show-area kiss before finish

The screen should not cut through the existing finish to bare wood. If you see raw wood after the 120-grit pass, the existing finish was already worn through and the floor needs a full sand-and-finish, not a screen-and-recoat. Stop and reassess.

Between coats of polyurethane

One pass with a 220-grit 16-inch screen between each coat of oil-based polyurethane. For water-based polyurethane, the same 220 grit works — keep the touch light and vacuum thoroughly before recoating because water-based finish dust gums up easily. Never sand past 220 between coats: finer grits close the surface and the next coat will not bond properly.

Bare-wood sanding with the Power Drive

For full bare-wood refinishes using the Power Drive plate (instead of, or alongside, a drum sander):

1. 40-60 grit discs — first pass with the 15-lb weight kit installed. Replaces the 36-grit drum pass on jobs where a drum is impractical (small rooms, second-floor jobs, stairs adjacent to landings).
2. 80 grit — remove the weights. The lighter touch prevents motor strain on fine grit.
3. 100 grit — final cut for stain-ready or water-based polyurethane jobs.
4. Fine mesh (120 grit equivalent) — swirl-free finish prep, blends with edger work.

Some contractors run the Power Drive start-to-finish on smaller residential jobs and skip the drum sander entirely. The trade-off: slower removal on heavy old finishes, faster overall workflow on jobs under 500 sq ft because there is no edger-blend step.

How Many Screens or Discs to Buy

Buffer screens and 5-inch mesh discs last longer than drum sheets because the cut is much lighter. Plan accordingly.

Screen-and-recoat: 500 sq ft

Grit	16" screens needed	Notes
120	2	Add one extra if the existing finish is heavy
150	2	Standard quantity for refining 120 lines
220 (optional)	1–2	Show areas only; not always needed

Total: 5 to 6 screens for a 500 sq ft screen-and-recoat. Scale linearly: 8–10 screens for 1,000 sq ft.

Between-coats sanding: 500 sq ft

Budget 1 to 2 220-grit screens per coat. A single 220-grit screen will handle 500 sq ft if the floor is clean and the cut is light. Buy two and save the second for the next coat.

Bare-wood Power Drive sanding: 500 sq ft

Grit	Disc/screen quantity
40 or 60 (Power Drive discs)	3–4 sets
80	2–3 sets
100	2 sets
Fine mesh (120 equivalent)	1–2 sets

“One set” equals however many discs your Power Drive plate holds (typically four 6-inch discs). Always buy one extra set per grit. Hard species (hickory, hard maple, jatoba) wear discs faster — add another set on those jobs.

Species & Janka Hardness Reference

FlexiSand cut speed and disc life vary by species hardness. The same Janka reference table that governs drum-sander grit choices applies here:

Species	Janka (lbf)	FlexiSand notes
Eastern white pine	380	Use MultiDisc, not standard screen — single-rotation marks show on softwoods
Cherry	950	Burnishes easily; keep moving, do not dwell
Black walnut	1,010	Softer pores show screen marks — MultiDisc preferred for final pass
Red oak	1,290	Standard sequence works; calibration baseline for most published specs
White oak	1,360	Same sequence as red oak; tannin dust requires DCS-rated vacuum
Hard maple	1,450	Burnishes if you stop moving; budget extra screens
Hickory	1,820	Add 30% to disc/screen budget; ceramic-grain mesh lasts longer
Brazilian cherry (jatoba)	2,350	Use ceramic mesh discs; doubles abrasive life on dense exotics

Engineered hardwood warning: with a wear layer under 3 mm, never run the Power Drive below 80 grit. Use the standard 16-inch driver or MultiDisc only — the Power Drive’s aggressive cut at low grits will burn through veneer fast.

FlexiSand vs. Drum Sanders and Edgers

The FlexiSand is not a replacement for a drum sander on full refinish work — it is a complement. How it fits in the job sequence:

• vs. Silverline SL-8 / Clarke EZ-8 (drum sanders): Drum sanders cut. The FlexiSand finishes. On a typical refinish, the SL-8 runs 36 → 60 → 80 → 100 in the field, the edger handles the perimeter, and then the FlexiSand with a 120-grit screen blends the field-to-edge transition. Skipping the FlexiSand step is the most common cause of visible scratch ghosting under finish.
• vs. Clarke Super 7R (edger): The edger handles the 6-inch perimeter the drum cannot reach. The FlexiSand’s standard driver does not get closer than ~6 inches to the wall either. The Power Drive plate gets within 1-1/2 inches — the only configuration that meaningfully reduces edger time.
• vs. Lagler Hummel (professional belt sander): The Hummel cuts more aggressively than any drum the FlexiSand is paired with. On commercial jobs and old painted floors, contractors run Hummel for the cut and FlexiSand DCS for the blend. On residential jobs the SL-8 or EZ-8 paired with the FlexiSand is the standard rental-scale combination.
• FlexiSand alone (with Power Drive) for small jobs: on rooms under 300 sq ft, second-floor jobs where moving a 200-lb drum is impractical, and stairs/landings, the Power Drive can run start-to-finish. Slower cut on bare wood than a drum, but no setup change between cut and finish passes.

For machine-specific sheet sizing on the drum sanders, see the Silverline SL-8 guide, Clarke EZ-8 guide, and Clarke DU-8 guide. For the perimeter machine, see the Clarke Super 7R edger guide.

Common Problems and Fixes

Swirl marks under finish on softer woods

Standard 16-inch screen on a 175-RPM rotary motion leaves a single rotational pattern that telegraphs through finish on pine, walnut, and figured maple. Fix: switch to the MultiDisc plate for the final two passes. The independent 5-inch disc rotation cancels the directional pattern.

Burnished spots that will not take stain

Pad dwelt in one place too long, friction closed the wood grain. Re-screen at 100 grit to reopen, then proceed to 120 and finer. Train operators to keep the machine in continuous motion — never let it sit running on one spot.

Screen tears mid-pass

Screen wrapped around debris (a finish chip, a nail head, a staple). Inspect the floor before each pass. After 80-grit drum work, vacuum thoroughly before mounting the FlexiSand screen.

Power Drive bogs down on first pass

Either the weight kit is installed at too high a grit (remove weights at 80 and finer), or the previous drum cut was insufficient. The Power Drive is not a Hummel substitute for stubborn finishes — pre-cut with a drum or Hummel first.

Dust skirt drags or curls

Floating dust skirt clogged with finish residue. Brush clean between rooms. On heavy old varnish, expect to wipe the skirt every 200 sq ft.

Where to Rent or Buy the Bona FlexiSand

The FlexiSand DCS is less common in the rental fleet than drum sanders. Most professional flooring contractors own the FlexiSand outright because it is used on every job. Owned-machine economics make sense after roughly 30 days of use.

Rental availability:

• Local flooring supply stores — most likely source. Call ahead.
• Sunbelt Rentals and United Rentals — limited inventory; usually requires reservation.
• Home Depot and Lowe’s — typically do not carry the FlexiSand. Big-box rental fleets stock cheaper buffers without DCS dust containment.

The Power Drive accessory plate and the MultiDisc plate are sold separately from the base machine. Most rental shops stock the standard 16-inch driver only — confirm plate availability when reserving.

Where to Buy 16” Screens, 5” Mesh Discs, and Power Drive Discs

Virginia Abrasives manufactures 16-inch silicon-carbide sanding screens in 60, 80, 100, 120, 150, 180, and 220 grit, plus 5-inch mesh discs and Power Drive-compatible discs. Available on Amazon through the Virginia Abrasives store.

For Bona-branded abrasives (siafast 5-inch discs, Bona-specific mesh), order through Bona’s direct dealer network or specialty flooring suppliers. Big-box stores rarely stock 16-inch screens above 150 grit — order 220 grit ahead of time if you need it.