I'm working on a base for a credenza which is shaped roughly like 3 sides of a picture frame (or a U), with two vertical legs joined to a bottom base. The legs and base are mitered at 45 degrees and I confess to having cut them to length and mitered them before thinking that I should have left extra material for a tenon...doh! Nevertheless, I'd like to provide extra strength beyond just the end grain glue-up (The thickness is 1 1/2" and width of the miter ~4").
Is there a decent way to cut/drill the mortise for a floating tenon in mitered end grain? In long grain, I'd use some combination of the drill press and chisel. I don't love digging out a mortise on end grain, but the material is thick enough that I think I could do that if there's no better idea.
Alternatively, is there a better way to add strength than the floating tenon? Also, I have to do another set of base and legs (for the rear of the credenza)...would it be best to do integral mortises for those? I've never cut a miter with a tenon integrated in to it, but it seems doable (if not as simple as just sawing off the miter at 45 degrees).
All thoughts appreciated!