Here you can see N. passing one of the cutting boards through the drum sander. Talk about a wonderful machine! If you don't have a drum sander, have fun sanding! Alternatively, if you have a cabinet shop in your area they might be willing to run your assembled boards through for you. It's been my experience that they'll charge you around $2 a minute - this is an incredible bargain - it will only take them about 2 or three minutes to do, versus the 45 min to an hour (or more!) it can take using a palm sander. Really, it just depends on how out of whack the slats are after clamping.