Re: dado fingers question
I agree that box joints just expose the maximum amount of end grain and create horizontal joining surfaces where none are needed. All of this invites water penetration and premature rot. Butt or rabbet joints are much better in my opinion (and experience), modern glue (titebond III) and power driven screws are better, faster, and more secure than box joints and nails. If you are not making 100's of boxes and don't want to take the time to make a jig, you can use a 2" square piece of wood clamped to the "short" piece to keep things square while you screw the "sides" on. No need for special blades or table saw jigs, everything can be done well with a rip fence and a cross-cut guide. I make all mediums, a 1x8 board 6' long makes one box. 6' boards are usually cheaper and of better quality than the longer boards, I prefer lumber yards that are self-service, I can sort through the pile of utility grade boards to find the ones that will work for beehive boxes.
life is finite while knowledge is infinite. - Zhuang Zi