In the absence of any other way why not start the mortises off with a router and go as deep as you can, then finish to depth with an auger bit, chisel and mallet? No need to go to the complexity of squaring the shoulders or cutting the splayed verticals that a foxed (wedged) tenon requires, although (draw-bore) pinning the joint would add a lot of extra strength and with 2in of depth you have just about enough material to do that with
"Unfortunately there is lots of bad information online; some of it is really scary. It's probably not intentional, but I've seen some content that sets up the illusion that you can do whatever you want and get away with it" - Norm Abram in an interview with Jefferson Kolle
Last edited by Phil P; 02-18-2015 at 09:52 AM.