I have quite a few dovetails to cut in the upcoming months. One part of the process I always felt very weak was in the transfer of markings from one piece to another. Whether you do tails first or pints first, at some point you need to clamp the to parts together and do a transfer.
I have seen a few different variations on this idea, this is just my take. Essentially the two boards need to be held at right angles, and up against a fence that references two sides of the boards as co-planar. I don’t normally keep around extra big plywood because I don’t have the room to store it. I found out lowe’s has 1/4 sheets of “lauan grade” plywood. Not as good or as pretty as birch, but it looks stable enough for jigs, and was much cheaper.
I started by using pocket holes to join the base. together. I relieved the edges up against the fence with a plane to make sure no dust would keep the aligned boards from interfacing with the fence. A 90 degree cut of plywood made a fence/reference surface for the boards. I made sure the base was good and square before nailing in the fence. The fence only protrudes enough to act as a reliable alignment surface.
This might have been good enough, but I wanted additional assurance that it was square, and a little help lifting it up off the table. These blocks do both as well as stiffen the jig.
To demonstrate the use of this jig I have a (admittedly poorly cut) dovetail that needs transferring. The jig sits on the bench top, or could be clamped down. Adjust the two boards to be jointed until they are lined up. When set, transfer the edges of the cut dovetail to the pin board as shown. Because the jig hangs out over the edge, a really tall board could be dovetailed without issue.
This simple easy jig should be helpful in the months to come. Hopefully I reference it soon with high praises.