On Wednesday, February 19, 2020 at 9:50:15 AM UTC-8, John McGaw wrote:
On 2/19/2020 12:20 PM, Scott Lurndal wrote:
John McGaw writes:

A tightly fitting, correctly glued box joint should be stronger than
the wood around it. I don't see the necessity of additional reinforcement.

Assuming that the joint is fitted well and the glue involved is guaranteed
to never creep under constant load then reinforcement is not needed.

It's hard to be sure that a cross-grain joint (box joint) won't be stressed, internally,
by wood movement in addition to a constant load stress. That makes it a little
less certain than a dovetail (where some wood could do brittle breakage), and
a lot less certain than a dado (where a 12" shelf has a half inch under its dado socket)
that must make a 12" long check that splits 6 square inches of wood faces.

For what it's worth, old box joints do NOT stand up; hide glue gets eaten by fungus,
in about 150 years...