Editor's note: This is a guest blog post from Charles Murray, an experienced period furniture maker based in central Ohio and instructor at the Artisans Guild.
This is the first of a four part series building a hanging wall shelf in tiger maple. The shelves are attached to the sides without fasteners using long sliding dovetails and hide glue. It's based on 18th century examples but likely has predecessors in the 17th century.
In my last post, the lathe tool holder used straight sliding dovetails. I could use straight dovetails since they were only 1 1/2” long. On this project they are 8” (the depth of the shelf), so tapered dovetails are called for. Introducing the taper allows the shelf to slide into its socket more easily during glue-up. Once the shelf is in place, the dovetail will be in compression the whole length, providing a secure mechanical joint. Even though we will be using hot hide glue (which will act as a lubricant until it sets), straight sliding dovetails would likely introduce too much friction and seize before the shelves are fully seated. Something else that makes this project tougher is that it’s made out of tiger maple, which is more difficult to work with. That means all tools need to be sharpened and ready to work.
I first laid out a template using a compass on 1/4” plywood. After cutting it out, I used a chisel and rasp to clean it up. The thin plywood needed to be supported while I worked it, so I placed it in a vise along with a thicker board (Fig 1).
Normally I would lay the sides on two separate pieces of wood and cut my sliding dovetails before I cut out the concave and convex elements. However, since I nested the sides (Fig. 2) in order to conserve material, I cut the sides out first (Fig. 3) When cutting the sides out, I left an approximate 1/8” margin in case of blowout from sawing. I then did a rough cleanup with chisel, gouge, spokeshave, and rasp, making sure I leave extra where the female dovetail comes through. This will be cleaned up after the dovetails are fitted (Fig. 4).
Using a dovetail plane, I cut the male part of the sliding dovetails on the shelves (the pins). In the photo you can see that I have a scrap piece clamped to the backside to prevent spelching (Fig. 5). On figured woods it’s sometimes helpful to wipe the area to be cut with a wet rag; this helps lessen the chance of tear-out (Fig. 6). You can see in the finished cut (Fig. 7) the shavings left by the cross grain cut and the next photo shows the profile of the plane (Fig. 8). After both sides (top and bottom of the shelf) have been cut, I placed a tick mark on the top-rear part of the dovetail to reduce it by about 3/32” (Fig. 9). Using a straight edge I scribe a line along the end grain of the long pin that connects the tapered scribe mark with the opposite (non-tapered) end. Following this line, I pared the pin down with a chisel or a side rabbet (Fig. 10). This makes the sliding dovetail thinner at the back. By just tapering the top it keeps the shelves square to the back.
On period examples, a plate groove is often found near the back edge of shelves that allowed plates to be propped against the wall with the plate’s rim resting in the groove. To cut this feature, I used a plough plane to cut a simple groove 1 1/2” in from the back edge. To make the groove round, a #4 round moulding plane is used. As the plane is pushed along the groove, I used a rolling movement, tilting to each side of the groove and making it 5/16” wide (Fig. 11). While making this groove, it will cut into the dovetail, however, this will be hidden when once assembled. After the first shelf is completed, I use it to mark the length of the other two, using it as a story stick (Fig. 12).
This is part one of a four part series building this period wall shelf. Part two will describe the process of laying out and cutting the groove into which the dovetail will slide.
Charles is one of our woodworking instructors, teaching intermediate and advanced skills. Check out our class calendar for upcoming woodworking classes (the 2020 schedule is not finalized yet).