One way or another, get one of these babies! Aside from the band saw, this will save you the most time, and add a level of finish to your products that really makes a difference. Besides, it's not like it's only good for working kydex! Mine is a cheapo Ryobi that I purchased a for $99 plus tax. It has a 4inch by 36inch belt which does the bulk of the work, and then also a 6inch circle that i like to keep some find paper on for touchup.

Don't get me wrong, this isn't going to get you out of sanding, but it will make the long arduous parts much more pleasant. (and fast!)