I have 45sq mtrs of European oak tg flooring 190mmx20mm to lay on joists in my loft conversion, lengths mostly 3mtrs plus, I am going to finish the floor with 2 coats of Liberon floor sealer plus 2 coats of Liberon floor wax. There are rather a lot of knots that will require some sort of filling. What is the best way to deal with knots in European oak to provide the most descrete finish?
The best option is to sand the floor once it is installed with at least grit 80, collect the sand-dust, mix that with wood-filler and fill the knots with it. After it has dried you sand again with grit 120 to remove any excess filler.