I am building a cal king bed frame out of black walnut. I need to glue boards on the short edge vertically. They will be 84" long. In order to ensure they can withstand the stresses, I am thinking of adding grooves to the edge that will be glued. The grooves I am thinking of doing are either a "Tongue and Groove" or "Finger Joint" with a router bit. See images. I am also considering a 45° groove on the corner connection- but without glue. Instead I would use a steel bracket to reinforce the bed corners.
What do you think is a stronger connection- finger grooves, or the tongue and groove. And do I need the 45° grooves, or should I just bud the wood and brace with a bracket?