This article discusses what to do when applying more than 2 coats of Bona Waterborne product in a day.
-Our normal recommendation is no more than 2 coats of waterborne finish per day. However, you can successfully apply multiple coats per day if properly using extra air flow during the drying/curing period and monitoring each coat with a good pin-less moisture meter (i.e. we usually use a Wagner L-607 Dual Depth meter)
To begin, before any liquid product goes on the floor, take a moisture reading of the wood to get your base point (say 8% in Colorado).
After the first coat of finish goes on (all air is off at this point) and has enough time to flow, level and tack-off on top (not sticky anymore); we will then turn the air back on, place a box fan in the doorway, etc; anything to help move the moist air off the surface of the floor.
We will then go back and taking a moisture reading about every half hour until we are within two points of our base (in this case it would be 10%).
Then the bottom coat is dry enough to apply the next coat. By using air flow and the pinless moisture meter, we can apply multiple coats in succession and or cut down the dry time in between coats to about half.
Note: Other manufacturers may vary in how close they want you to the base reading, but Bona’s is 2% points.
If you don’t use a pin-less moisture meter to monitor the coats, you can end up with soft finish, a white haze in the finish, a surface that scratches, scuffs and is less chemical resistant; and possibly some blotchiness too.