On March 9, 2004 Brad Smith gave a demo for the Chicago Woodturners on turning birdhouses using cedar stave construction.

He starts with a 2 x 6 piece of cedar and cuts a series of ½-inch thick staves using a thin-kerf blade, about 9" long and maybe 1-1/2" wide. There are three mathematical formulas involved in determining the diameter of your birdhouse, and the number of staves required. In general, Brad makes them using either 9 or 12 sides.

The three formulas are:
Circumference = 3.14159 x diameter
Width of Stave = Circumference/No. of Pieces
Bevel Angle = 360 degrees/No. of Edges*

*Note: No. of Edges is double the number of staves

Example No. 1
Consider a 12-sided birdhouse 6" in diameter. The circumference of such a birdhouse will be 18.85"; the width of each stave will be 1.57 inches; and the bevel angle on each piece will be 15-degrees.

Example No. 2
Consider a 9-sided birdhouse 6" in diameter. The circumference of such a birdhouse will be 18.85"; the width of each stave will be 2.094 inches; and the bevel angle on each piece will be 20-degrees.

It is critical to achieve the proper bevel angle on each piece, as the magnitude of any bevel angle error will be multiplied by twice the number of staves in the piece. For example, if you were off by say, one-half a degree on a 12-sided birdhouse, then you would be off by a total of 0.5 x 24 or 12 degrees in the finished piece.

Brad makes most of his staves 9" in length, but on a 12-sided birdhouse, every fourth stave is about 8-5/8" long, to provide three slots for ventilation at the top of the birdhouse.

Entrance Diameter
You want to think about what sort of birds will inhabit your birdhouse, as this will determine the diameter and height of the entrance hole. Following is a table that provides parameters on different bird species.

Once the angles are cut into each stave, and each stave is cut to length, Brad places the staves against a roofing square, backside down. He uses a piece of duct tape under the staves to help hold them together. He then applies Titebond II glue (you can use a Titebond III waterproof glue, currently available at Rockler, as a preferred alternative). The duct tape is then used to unite all the staves, and a stainless steel hose clamp is placed at either end of the cylinder to force the pieces together for gluing.

Once the glued-up cylinder has dried, it is mounted between centers on the lathe. The headstock end has a tapered disk, made out of a 2x6 or 2x8 white pine, with a center screw from the chuck holding it in place. The edges of the disk are tapered to accommodate the glued-up staves. A similar tapered disk is placed on the tailstock end of the lathe, which is fitted with a large 60-degree center that fits into the centrally bored hole in the tapered disk.
The outside of the coopered cylinder is rounded with a gouge (Brad prefers to use a bowl gouge), and then smoothed with a skew chisel. Note: it is not necessary to turn the inside of the cylinder.

Top and Base
Brad uses a pair of glued-up 2" thick disks for the base, and three 2" thick disks for the top. These glued-up disks are bored all the way through the center. The top assembly is mounted to the screw-chuck in the headstock with the big-diameter disk facing the tailstock end. A parting tool is used to establish a grove in the face of the largest disk. The outer diameter of the birdhouse cylinder will fit into this grove. Trial-and-error is necessary to get the proper fit here. The top of the cylinder will be glued into the grove turned in the top. Don’t make it too loose!

After the grove in the underside of the top is completed, reverse the top in the chuck and turn the outside to final shape. NOTE: once the outside design is completed, hollow-out the inside of the top from the headstock end of the lathe. This will create a “vaulted ceiling” effect and reduce the weight of the top.

For the base, insert the two glued-up disks onto the screw chuck, again with the larger disk facing the tailstock end of the lathe. Using a parting tool, first turn a ½" tenon near the outside of the base, sized to fit inside the turned wall of the birdhouse. (You do it this way so that screws can be attached through the outside of the cylinder to attach the base to the bottom of the cylinder.) Once the tenon is established, turn a concave shape on the inside of the base. This will facilitate drainage of any water that might enter the floor of the nest.

Next, turn the external profile you wish to use on the outside of the two base disks. Use screws in the outside of the turned cylinder to attach it to the base piece.

The Finial
Prepare a blank for the finial (on the top of the top) by boring a hole to accommodate a 3/8" diameter dowel rod. This dowel rod, once glued into the blank, can be used to mount the finial blank to the headstock for turning.
There are multiple strategies one can use here. For those with deep pockets, one can purchase special jaws for their chuck that can grip pieces that are small in diameter. But if you want to save money, Brad suggested the use of a 3/8" bolt with the head cut off. The "smooth" end of the decapitated bolt can be fitted into a headstock fitted with a Jacobs chuck, and the threaded portion of the bolt can be used to mount the finial blank. Once the profile of the finial is established, it can be removed from the bolt, and a dowel rod can be glued into the hole in the bottom of the finial.

Yet another approach would be to glue the dowel rod into the base of the finial blank up front, and then slide a bushing over the outside of the dowel rod. Such bushings are available at your local hardware store. Once the bushing is slid over the outside of the dowel rod, it can be gripped by the three jaws on the Jacobs chuck mounted to the headstock of the lathe. Turn the finial to the desired shape, and then remove the dowel from the Jacobs chuck and remove the bushing.

Finishing
Brad suggested using a couple of coats of Thompson’s Waterseal to help weatherproof the outside of the birdhouse.

NOTE: Don’t put a dowel-rod perch below the entry hole. Larger birds, such as blue jays, are known to use such a perch as a standard, and then stick their heads into the entry hole to dine on eggs left unattended.