Through Wedged Mortise & Tenon

The through wedged mortise and tenon resists pulling apart due to the dovetail created by inserting wedges.

Begin by producing a through mortise and tenon in the normal way

Then prepare some wedges, approximately 4-7degrees, 3/4 the length of the tenon, and a slip fit across the mortise width.

Make a saw cut towards each end of the tenon, about 3/4 the way to the shoulder. These will accept the wedges

Widen the rear of the mortise on each end, by the thickness of a wedge (fat end) minus a saw kerf.

Pare the widened mortise ends down to the original width at a point 3/4 the way towards the front of the mortise. Creating a dovetail shape inside

This will allow the wedges to fit tightly in from the rear

Glue and insert the tenon as normal. Then apply glue to the top of the saw kerfs and the wedges...

...and drive the wedges home, being careful to strike them squarely, so as not to break them

Once cured, the excess tenon length and wedges are planed flush

Now watch the video: