Reply To: Bridle vs Mortise & Tenon joint

If experience isn’t understood as skills, then I have some on the bridle joint (slip-joint with another – possibly more correct – name. Anyway, here’s my farthing, mainly based on windows and doors.

Basically, I think the slip-joint is confined to stand alone frames (doors, windows, and [well] frames). It does not seem to be a good alternative for caseworks, as the joinery of any piece to be attached perpendicular to the corner of a slip-jointed frame would damage to the slip-joint.

Furthermore, its use is probably limited by the size of the frame. Large frames, as front and interior doors, seem to be very keen to twist; probably because of gradients in temperature and humidity along their heights. Wide stiles and bottom rails, allow for tall (often double) tenons, which I believe interlock with the mortices: the rails cancelling the warp of the stiles, and vice versa. The open end of the slip-joint perhaps results in poorer interlocking properties, I guess.

The slip-joint is quite great for making windows up to a size. One can make the rebates for the panes before cutting to dimension, and then close the gap made by the rebate by shorten the tenons on rebated side to the width of the rebate.

The strength of both mortice-tenon joints and slip-joints can be enhanced by pegs or drawboring. Please see attached photo of a drawbored century old glazing bar. The window needs to be replaced, but the joinery looks to be …