Make a Tapered Sliding Dovetail
A router, plywood fence, and shim make easy work of producing this sturdy mechanical joint for shelves and partitions
The tapered sliding dovetail is an ideal joint for joining shelves or partitions to a carcase. The sliding dovetail joint provides a strong connection, and the additional taper makes it easy to assemble the joint without binding during glue up. In some orientations, the taper can also help keep the joint tight with gravity.
The joint is not much more difficult to produce than a standard sliding dovetail or even a dado joint. The process is detailed in this audio slideshow, which incorporates demonstration photos from woodworkers Garrett Hack and Martin Milkovits.
Cutting the joint
To follow these techniques, you will need a simple plywood fence that has parallel sides, a thin shim, and a router set up with a dovetail router bit. The first step is to clamp the plywood fence in place so that the router can register against it as it is used to plow the straight dovetail slot. Next, shim one end of the plywood fence to widen one end of the slot, and take a second pass with the router to taper the slot.
To cut the dovetail on the tail board, the process is similar. First, rout a straight dovetail edge along one side. Make sure this side corresponds with the straight edge on the dovetail slot. Next, attach the shim to the wide end of the tail board and rout that side, completing the tapered dovetail. With proper test cuts and setup, the joint should go together with some resistance.
Audio Slideshow Produced by Matt Berger. Photos by Tom McKenna.View PDF