Windsor Chair repair

[Setch]

I've repaired a few spindle backed chairs in the past, and this has mostly been a case of fresh glue, and fresh wedges in the wedged through tenons under the seat.

This one is a bit more challenging. It's the second attempt on this chair. The first attempt with new wedges and liberal quantities of liquidhide glue worked a treat at tightening the tenons up, but alas, one tenon was not longer attached to the back.

Spot the difference!

 

[Setch]

So, how to graft on a new tenon, ideally without it showing?

I considered trying to drill down the endgrain for a dowel, but wasn't convinced I could do it accurately, and I wanted to maximise the glue area, ideally without removing what little was left of the tenon, as this would help me cut the new tenon in the correct place.

So, improvised horizontal mortising rig:




The little Makita trim router is clamped down securely, and the height of the workpiece adjusted by stacking MDF offcuts till I was happy - 2 bits of 12mm seemed about right. I clamped another piece of 18mm MDF to act as a fence for left/right location.




I did a first experiment with a 1/4" straight cutter, sliding the workpiece forward into the cutter, and simultaneously side to side, like a domino, but moving the work not the cutter. That worked smoothly, with no tendency to snatch or chatter, so I stepped up to my extra long 3/8" cuttter.

The result was this nice clean mortice.

 

[Setch]

Next, I'll need a tenon. I cut one on my tablesaw crosscut jig, then traced round a 3/8" bearing so I could shape a matching radius to the mortise.


I little chisel and file work produced a nicely fitting tenon.



I knocked the joint together with a hide mallet, and then couldn't get it apart - I clamped it in the vice id my workbench, and actually lifted the entire bench, and attached drawers while trying to pull it apart.