A turning project
I was asked to make a birdhouse in the shape of an egg. This series of photos illustrates what I did to turn it from a piece of oak firewood.
Although the result is usable and I hope the birds find it inviting, this piece was basically a prototype to iron out the details of the procedure. The blank came from a standing dead tree and was well seasoned. I learned a lot: don’t use oak with a knot. It’s too hard!
This is a fun project that provides practice for several turning skills like shaping a curved profile, hollowing end grain, and joining two pieces together. And if it doesn’t turn out quite as well as you had hoped, just hang it higher in the tree.
Mount the blank between centers and true it up. Form a tenon at each end. Shape the approximate outer profile of the egg. Cut the blank into two pieces. Hollow each section and form the lip and recess for the join. Reconnect the parts and do the final shaping of the outer profile. Part it off and sand away the remnants of the nubbins. Drill the access hole off the lathe and install the hanger.
Let’s do it!
The first step is to mount the log between centers and clean it up.
Now it’s time to separate the two sections. For me it’s not just a simple matter of ramming a parting tool through the spinning blank because I had a little incident with a parting tool one time and it still sticks in my memory. (See article.)
What I now do is go part way with a parting tool and then finish the cut with an old fashioned handsaw (lathe OFF, of course).
The next order of business is to hollow each section. I did the one that will be the bottom of the birdhouse first.
This is where I realized how hard the interior of this blank was. I switched from a bowl gouge to a Sorby Hollowmaster (See article) in order to remove as much waste wood near the rim as possible while using tailstock support.
Sometimes things do not go smoothly. The interior was almost completely filled with a knot. Do you know how hard an oak knot is? Without tailstock support, it was difficult to keep the blank in the chuck.
After completing the hollowing, it is a good idea to put the blank aside for a day before forming the lip to allow time for any wood movement to occur if the blank is not completely dry. Otherwise you risk having the top and bottom sections warp until they will no longer fit together.
Rinse and repeat: hollow the top section in a similar manner except form a recess for the join.
Next up is to jam the two sections together and do the final shaping of the outside, which I did completely by eye. It’s hard to mess up an egg unless you accidentally turn a perfect sphere.
I elected to use small cotter pins to hold the top and bottom together. By spreading the legs, you can create enough friction in the slightly oversided holes until (hopefully) they won’t work out over a season. Small screws could be used but that would require a “tool” in order to open the cavity for cleaning.
Now to get it off the lathe. The blue tape keeps the cotter pins from flying out.xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
I drilled the hole with a 1 1/8” Forstner bit on the drill press, but not all the way through for fear of having the bit break through on the inside. I finished the cut with a coping saw and then smoothed the surface with a small drum sander mounted on my lathe.
And here is the end product. My designer opined that the eyebolt I used for the hanger could be smaller, and the birds might appreciate a perch, which I understood to be optional. A coat of mineral oil and beeswax on the outside is the only finish applied (later), mostly for cosmetic reasons for presentation.
Note: A chickadee occupied the house within two days after it was hung up.