How to apply Bona: one coat of ClassicSeal followed by two coats of Mega or Traffic.

If you watch our YouTube video on screening and recoating a floor, skip to the very end where we’re actually spreading the polyurethane; that’s the best demonstration of our technique we can possibly give you.

Remember that Bona ClassicSeal, AmberSeal, Mega, and Traffic are all water-based products; use water for all cleanup.

Do not use paint thinner, turpentine, alcohol or lacquer thinner.

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    Vacuum on hardwood floor
    Step 1: Vacuum, vacuum, vacuum

    Use a good vacuum to make absolutely sure there is no dust, debris, or foreign matter of any kind left on the floor. It’s best to use a shop vac or canister-style vacuum that uses a wand with a soft bristle brush attachment rather than the upright vacuum you use for carpet.

    After you vacuum, wipe the raw wood with a soft, DRY rag (old t-shirts are perfect) to get up the last specks of dust that the vacuum left behind. Then run the vacuum over your dry applicators to eliminate loose fibers. If the room you are about to coat is adjacent to a floor where you don’t want spills or drips, use blue tape to protect it.

    Tape down some cardboard at your exit door so you have a safe zone to place your sticky mop and pad painter as you back out of the freshly coated area.

    Open window with fan
    Step 2: Open a window, keep to 60°

    Make sure that at least one window in the room to be coated is open 3″ or more and that you can maintain a temperature of at least 65 (70 is better) degrees Fahrenheit for the duration of the drying and curing process – not just while you’re coating.

    You will improve air exchange and maximize your cure rate if you turn on a fan (like a bathroom vent fan) in an adjacent room to make sure that the coated rooms are emptied of air four to five times an hour.

    Bona ClassicSeal wood floor finish
    Step 3: Gently shake, prepare t-bar

    Before you crack the seal, gently agitate your jug of Bona ClassicSeal to stir. Open the lid and insert the small plastic strainer into the jug opening.

    Slide your coater cover onto the metal t-bar and make sure the t-bar is securely attached to your threaded pole. Stick a clean, dry rag in your pocket so you are ready to deal with drips.

    Cut in finish with pad painter
    Step 4: Cut in with pad painter

    Start at the wall that is furthest from your exit and runs parallel to the wood grain. Pour a 5-inch-wide puddle that runs the entire length of your starting wall, about 3 inches from the wall. Begin cutting in with the pad painter, but don’t cut in the entire room!

    Coat a 6-inch border along your entire starting wall and 3 feet along the walls that abut your starting wall.

    Applying finish with a covered t-bar
    Step 5: Dip applicator, press lightly

    Charge up your t-bar coater with polyurethane by dipping the applicator end in the puddle and then pressing lightly against the floor.

    Do this several times, until the applicator appears evenly filled with finish, but not drippy (similar to how a paint roller feels as it leaves the roller tray).

    Applying finish with a covered t-bar
    Step 6: “Snow-plow” the finish in front of the applicator head

    Begin at the top corner of your cut-in zone and gently drag your t-bar at a 30º angle, aiming the center of your 18-inch coater at the center of your puddle of polyurethane, effectively “snow-plowing” the finish in front of the applicator head.

    Walk in a straight line, parallel to the wall and without stopping, until your t-bar reaches the cut-in section at the far wall.

    Don’t lean your body weight on the stick; the weight of your two hands on the t-bar is all the pressure you need to lay down the correct amount of polyurethane.

    Step 7: Overlap your last pass

    Lift your t-bar and gently wring it out by pressing it against the floor that is already wet with polyurethane. Start from the cut-in zone and overlap your last pass, again dragging the puddle parallel to your starting wall all the way to the wall at the top.

    If you’re coating correctly, the puddle will slowly shrink because each pass with the t-bar applicator will leave behind an even film of polyurethane.

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    Step 8: Cut in another 3 to 4 feet

    When you reach the end of the area of the original cut-in zone, rest the t-bar with the applicator in the wet polyurethane (leaving it on the dry wood leaves a permanent mark), and cut in another 3 to 4 feet along the walls at the top and bottom of your next coating zone.

    Pour a fresh line of polyurethane if necessary. Continue alternating t-bar and pad painter until you are 3 feet from your final wall.

    Applying finish with a covered t-bar
    Step 9: Coat your last exit stripe in sections

    Use your pad painter to cut in along every wall you have left, except for your exit. Starting at the corner furthest from your exit and working a 5-foot section at a time, gently mop the polyurethane on with a back-and-forth motion.

    Scrape the excess finish down into a puddle at your feet, then go back and blend your coated section into the cut-in zone by pushing the t-bar away from you while you gradually lift it off the ground. Work backward, blending each section into the last, until you reach your exit door.

    Switch to the paint pad for the last few strokes. Remove your coater from your t-bar and the pad from the pad painter and keep them both soaking, subermerged completely in water until your next coat!

    If they dry out and crust over they will not spread polyurethane evenly and you’ll need to buy new ones.

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    Step 10: Dry four hours, but not more than 24

    Your layer of sealer must be dry enough to walk on before you apply the next coat. With a temperature of 65 -70 degrees with good air exchange, this should take three to four hours. You can apply your first coat anytime after it it dry enough to walk on with leaving footprints, up to 24 hours

    What if it feels really rough after it dries?

    This is to be expected! Water-based finishes are likely to raise the grain, and your finish will harden around those little raised particles, making the texture rough. If you would like to sand that back for a smoother floor, do NOT sand the sealer! Wait until 12 hour after your first coat of Mega or Traffic HD. The surface will be much harder and less likely to gum and grab as you try to sand.

    Step 11: Apply your first of coat of Mega or Traffic

    Using fresh applicators, and relying on the skills your learned is steps 4-9, apply your first coat of Mega or Traffic HD. Wait at least four hours, but not more than 48. If the floor feels smooth, (or it it feels rough, but you don’t care) you may immediately apply your second coat of Mega or Traffic.

    If you would like to abrade your first coat of Mega or Traffic because it feels rough, wait at least 12 hours after the first coat, abrade with 150-180-grit using a sheetrock screen or flooring buffer, vacuum, then wipe with a cloth lightly dampened with water. Once the water dries, apply your second coat of Mega or Traffic.

    Rinse your applicators after use, and store them submerged and weighted down in water so they do not dry out or become crunchy!

    If you are coating with Traffic HD be sure to only catalyze the amount of finish you need for one coat; the pot life of the catalized Traffic HD is only four hours.

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    Step 12: Apply your final coat of Mega or Traffic

    After four hours or after the your previous coat is dry enough to walk on without causing a footprint, apply your final coat of Mega or Traffic.

    Wait 24 hours after your final coat of polyurethane before allowing foot traffic or furniture back on your floors and wait at least two weeks to replace large area rugs.

    Pete’s Bonus Tips

    Open window with fan

    Heat, humidity and air exchange.

    No matter what the season, both oil and waterborne polyurethanes need THREE conditions to cure quickly and thoroughly:
    • low humidity
    • warmth
    • air exchange

    The air has to be DRY because heavy, moisture-laden air literally blocks oxygen from reaching the finish

    It needs to be WARM because the chemical reaction that cross-links and cures the finish will not proceed below 65°.

    And a constant but gentle source of FRESH, OUTSIDE AIR provides the oxygen that the finish must combine with in order to become a solid and fully cure .

    Some tips for creating the perfect curing scenario:

    If the interior temperature is likely to fall below 65° at any time during the coating or the first week after coating, turn on the heat!

    Don't point a fan directly at the drying floor; it will force dust into the wet finish. Use a fan in an adjacent room like a bathroom or kitchen vent that is connected to the outside, and leave it on. In warm weather you can put a box fan in a window (blowing out!) in an adjacent room. In cold weather, box fans in windows will suck out too much heat - just gap the top a window in each affected room.

    High humidity is the most difficult coating condition to deal with. Turning on the AC will bring the interior humidity down, but without opening windows, the evaporating solvents have no place to escape and fresh oxygen can't get in. But opening windows brings the humidity back up. Usually you simply have to resign yourself to longer times between coats and a longer overall curing time during the most humid months.

    For oil-based polyurethanes, you should keep one window in the coated room gapped to 3” for two weeks.

    Front of Pete's Hardwood Floors store in St. Paul, MN

    Buy online, or stop by our cute store in St. Paul, Minnesota.

    Pete's sells supplies online across the continental U.S., and rents equipment to Minneapolis/St. Paul DIYers. Our store at 186 Fairview Avenue North in St. Paul, MN is at the corner of Fairview and Selby.

    It's just the cutest sander rental shop you'll ever visit. Call us at 651-698-5888.

    Store hours:

    • Monday - Friday: 8:30-5
    • Saturday: 8:30-3
    • Sunday: Closed