Abstract: An automatic wood flooring boards reparation device for applying and spreading filler over boards is provided, the device comprising an infeed unit, an outfeed unit and a filler applicator. The filler applicator applies filler over a top surface of the boards with a head comprising a main body, a spreading device and a bottom portion, each part comprising an opening for distributing filler over the board and an opening for securing a scrapper for spreading the applied filler. A tight seal is created between a filler applicator opening of the bottom portion and the top surface of the boards to avoid overspill of filler. A method for applying filler is also provided.