A deduster is comprised of two sets (pairs) of counter-rotating dedusting brushes in co-operation with a vacuum system for saw dust removal from wooden lumber. In addition to these features, the deduster may feature a separate, movable, top brush assembly that can be easily adjusted for different board thicknesses and raised up to allow for clearing board jams and for pass-through if boards were to be run without dedusting. This deduster apparatus is modular, thereby allowing it to be positioned over an existing machine or a lumber board unscrambler machine such as a lugged unscrambler machine.