OK If you look at the cut list from the first post those 2×12x12’ are sliced up into a bunch of 33” long chunks and ripped in half and then again into 5 1/4” (for slop) The Tenon is achieved by tacking a block of Plywood (mine is 2 1/2”) wide at the Ends of two of the inner boards in the stack your going to glue up.
I then Set up a stop in my miter Guage and choped 2 1/2 Off the outboard pieces and glued and clamped them…
This is the setup before glue.. with the blocks of Plywood tacked in with 16 guage brads -
Then you clamp like crazy! This was taken after a hour or so… I removed the end clamps and popped off the Plywood so that it would not become part of the project.
I then Cleaned out the Top and bottom with a shoulder plane and block plane as needed and used my smoother to put a Chamfer along the bottom edge (this is help you move the beast if you need to with out chipping the edges out)
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