A widebelt does not produce a finish sanded product. It'd probably be good enough, but I still hit everything with an orbital on the interior before putting them together. Plus there will be little scratches and dings just from being machined, dado'd, and having the tear out ripped off of them prior to assembly. After I assemble drawers, I rub a little bit of glue into the joint then belt sand them flat, and they'll get hit with an orbital on the outside.