The glazing bar dowel joint quickly became superseded by the mitred joint. However, the joint itself (and the use of a sash dowelling box to make it) is of some interest to me. It’s actually very simple, as Richard Arnold showed me.

This beautiful sash dowelling box was given to Richard and resides in his tradition tool collection. He remarked on the excellent construction and the fact it seemed almost too professionally-made to be a user-made tool. After handling it, I would agree.
This beautiful sash dowelling box was given to Richard and resides in his tradition tool collection. He remarked on the excellent construction and the fact it seemed almost too professionally-made to be a user-made tool. After handling it, I would agree.

The screw underneath raises and lowers the end piece of the box, adjusting where the drill hole will be positioned on the butt end of the glazing bar.
The screw underneath raises and lowers the end piece of the box, adjusting where the drill hole will be positioned on the butt end of the glazing bar.
Insert your glazing bar, push it to the end and clamp down the screw on the top to hold it in position.
Insert your glazing bar, push it to the end and clamp down the screw on the top to hold it in position.

Makes sure it's fully seated or your hole will be in the wrong place.
Makes sure it’s fully seated or your hole will be in the wrong place.

Clamp the box endways in the vice and locate your bit into the drilling hole. The end box should already be raised to get the right height. Then just drill away.
Clamp the box endways in the vice and locate your bit into the drilling hole. The end box should already be raised to get the right height. Then just drill away.

There you have it. Your glazing bar is now ready for a dowel joint.
There you have it. Your glazing bar is now ready for a dowel joint.