Repairing a broken tenon joint:

One of the bottom stays on our chair had a neat angle bracket fastened to the underside. When the bracket was removed, the joint fell apart.

I carefully chiselled out the broken tenon, taking care not to aggravate the problem by enlarging the mortise.

Next, I cut a 30 mm-deep slot into the stay. Here you should be careful to cut the slot no wider than the mortise, and to match the offset angle of the original tenon.

With a new tenon cut from a piece of offcut oak and glued into place, the joint was as good as new.

APRIL 2020