When broken apart slowly, by hand tools, the wood failed, but quite close to the glued surface.
To me, this indicates that more penetration is desirable.
I will try some more test pieces, coating a freshly cut wood surface with clear epoxy first, then applying J-B weld before it cures. i.e. allowing clear epoxy & J-B Weld to mix right at the join, hoping that the clear epoxy will penetrate deeper into the wood.