finished this humidor not long ago

well there is obviously no finish on the interior spanish cedar. The exterior black walnut is first coated with a tung oil or linseed oil based finish such as waterlox or watco danish oil which is applied and then wiped off and allowed to dry for 24 hours. After that I sprayed a conversion varnish, 1 primer coat and then 2 finish coats not exceeding 4-6 mils of finish thickness, which is what the manufacturer recomends. In between each coat I scuff sand with a minimum of 400 grit sand paper. I have been using this finish and methodology for the last 12 years on a variety of architectural and furniture projects and although it has evolved the basics are pretty much the same. hope this helps