Water-based hardwood floor finishes are a popular choice among flooring professionals as they dry quickly and don't have the odor or chemicals of oil-based finishes. The quick drying time does leave little room for error, which is why following the correct application process for each coat is crucial.
Clean and Sand the Room
Sand the floor with a sanding screen or a sanding pad to create a smooth surface before you put on the finish. For best results, the room should be completely clean before you apply the finish. Remember to clean crevices, walls, window sills and any other areas that could hold dirt or dust.
The ideal temperature to apply a water-based finish is between 65 and 70 degrees Fahrenheit. Use heating or cooling as necessary to get the room to an acceptable temperature. Make sure the heat or air conditioner is off before applying as the draft may affect the finish.
Start Applying the Finish Along a Wall
Before using the finish, mix it according to the manufacturer's instructions. Depending on the finish type, mixing can be as simple as shaking the container, or it may involve mixing in a hardener and straining the finish a few times.
Be sure to use a synthetic applicator to apply the finish as these applicators spread the finish instead of soaking it up. For large areas, T-bars are the best choice. Brushes, rollers and pads are all good for filling in small spots.
Choose a wall as your starting point, and apply a line of finish along the edge of that wall. The line should be at least a 4 inches wide, and it must follow the direction of the floor's grain. Put your applicator on the floor, and cut into the finish. Then, use it to brush the finish up and down the floor, covering a couple of feet of the room. Apply a moderate, consistent amount of pressure when you push the finish, but don't push down on the applicator while pulling it towards you. Aim for smooth strokes without too much excess movement as this may cause bubbles.
Turning at the End of a Run
When you reach a wall and have to start a new run, turn the T-bar towards the unfinished section of the floor, being careful to keep any extra finish off the wall. Lift the T-bar off the ground, and gently set it on a dry part of the floor next to your pour line. Pad the applicator by moving it back and forth a bit. This takes some of the finish off your T-bar so you don't put too much on the floor when you make the turn.
Put your T-bar up against the wall by your turn line, and pull it through the finish to start a new run. As you pull, slightly lift the applicator. This feathers out the turn line so the whole floor looks consistent with an even finish.
Continue Applying Finish to Cover the Whole Room
You can repeat this application method to cover all of the room's hardwood flooring. During the process, pour additional finish onto the floor whenever you need to bolster your pour line. Always keep the pour line at a minimum width of 4 inches so you have enough finish for the next run.
Leave Space to Exit the Room
The last thing you want to do is trap yourself in the corner of the room, forcing yourself to walk over all your hard work. Plan out your runs in advance to ensure that your final run ends at the doorway to the room so you can just step out when you're done.
Finishing up once you get to the doorway can be a bit tricky. Ideally, you want a small amount of finish left, or you can pour some onto the floor to finish the job. Stand in the doorway, and pull the final pour of finish towards yourself, using a slight zigzag motion to spread the finish evenly on the last section of the floor. Leave a small dry area to pad out the applicator the same way you'd pad it out at the end of a run. Then, lightly go over the zigzag pattern to smooth it out and get rid of any turn lines.
Put On the Finishing Touches With a Cut-In Pad
Use a cut-in pad to pick up any extra puddles of finish, and drain it into any container you have available. Touch up the last section of the floor as necessary using your cut-in pad.
Wait to Add Another Coat
While you can find the recoat time frame on the finish container, water-based hardwood finishes typically take about an hour to dry and are ready for another coat in 2 to 3 hours. If the room is very humid or cold, expect the client’s floor to take longer to dry.
Once the floor is ready, follow the same procedure to apply another coat, completing the cleaning and sanding process once more. With certain finishes, you don't need to sand the floor again if you're applying another coat within 24 hours. However, you can still sand to ensure you get the best results.
Repeat the Process Until the Floor Has a Sufficient Coating
The finish creates a layer of protection over the floor, so you need to apply a sufficient number of coats. Water-based finishes usually have 30 to 35 percent solids, so you need four coats to fully protect the hardwood. If you apply each coat right away when the floor is ready, you can have the floor ready for the client within a day.
A water-based finish is great for protecting and showing off a home's hardwood. Apply the finish the right way to give your client's floor a beautiful sheen for years to come.