Join Boards End-to-End With a 45-Degree Cut and Dowels

The Problem

Sometimes the board is short and the project isn't, and joining length is the only way forward. A square butt joint is the worst joint in woodworking — two end-grain faces that drink glue and hold almost nothing. If you have no choice but to splice, the splice needs geometry on its side.

The Technique

1. Cut both mating ends at 45 degrees, so the boards overlap on a long diagonal face instead of meeting square.
2. Drill for dowels through the joint — about three of them, in the maker's judgment, even with the angled cut.
3. Glue the faces, insert the dowels, and clamp.

Why 45 degrees: the maker is explicit that the angle is there to make the glue work better — the diagonal turns two hopeless end-grain faces into a much larger, more face-grain-like glue surface. The dowels then keep the slippery angled faces aligned under clamping pressure and add mechanical strength across the joint.

The dowel layout and drilling registration are easier absorbed by watching the maker's hands run the sequence once than from any description — the video is a quick watch and worth it before your first attempt.