Applying as many heavy coats of finish as possible is best…
This is a common misconception. Multiple thick coats do not dry properly and will scratch easier. The total number of recommended coats of sealer and finish is normally three to four on a newly sanded floor. Most often, this includes one or two sealer coats and one or two finish coats. All coatings should be evenly applied at their recommended coverage rates. This will ensure proper drying, best appearance, and wear resistance.
Excessive top coatings tend to give the floor a look as if it were plastic or artificial. In the case of solvent-based finishes, which yellow over time, the appearance of the wood grain becomes obliterated. It will also get “murky” if you apply too many coats and do not allow the proper curing time for each layer. Too many coats can make it difficult to determine a wood species when numerous coatings have been applied over the years, giving a look of a painted surface.
The type of hardwood floor you have and use can determine the amount of finish coats you apply. Make sure you speak with an expert or your hardwood floor contractor if you have questions.