Vacuum cleaners may well remove surface dust, but they can\\\'t quite suck up particles (or post-sanding clumps) from between the gaps - which can either reappear when varnishing, or simply look unsightly when looking down the lines.
Very simply, use the pointed nozzle of a vacuum cleaner, and run it up and down two or three times. Remove any stubborn stones, particles etc using a kitchen knife, or similar (blunt edge of a Stanley knife for really narrow gaps).
Very simply, use the pointed nozzle of a vacuum cleaner, and run it up and down two or three times. Remove any stubborn stones, particles etc using a kitchen knife, or similar (blunt edge of a Stanley knife for really narrow gaps).