September 15, 2014 Woodturner’s Meeting at Denny Wetter’s shop.
This meeting began with a brief presentation of the work of Malcolm Tibbitts, aka the Tahoe Turner. His web site is: http://www.tahoeturner.com/index.html . Take a peak there for some outstanding segmented turning and the inspiration for this night’s project, a melted bowl. Unlike previous segmented projects, in which the segments were glued together to make horizontal rings, tonight’s project will consist of horizontal rings that comprise the segments and that are then glued to complete the project. The preparation of the segments is critical to this project and that procedure is described in the following narrative.
Denny began with a more or less square block of wood; one could also glue cutoffs or scraps into layers and build up a piece for turning as well. He mounted this piece in his chuck and turned a socket for chuck mounting. He cautioned to leave as much square as possible. Using his dovetail chisel that matches the angle on his chuck he turned a recess on the tail end.
He then chucked this recess in the headstock, effectively reversing the work piece and then made a socket in this end as well. He next used a parting tool to partially part off about ½” deep or so what will become the top of the melted bowl.
The workpiece was removed from the chuck and moved to the bandsaw at which point Denny said that the lid needed to be cut off, but not to cut it too straight. I thought that instruction would come naturally to me! The lid was labeled and set aside until almost the completion of the project.
The remaining block was sliced into layers, starting from the bottom and each layer was labeled with a number sequentially on either top or bottom, as to keep the grain pattern running through the piece when it is reassembled. Remember to not cut straight as the wavy cut is part of the design. Denny marked the approximate center on each piece and the pieces are moved to the drill press where small registration holes are drilled close to center, perhaps within an inch, and matching the diameter of an available wood dowel.
The future segments were then clamped slightly off-center and drilled about 1/4” deep with a forstner bit to facilitate chucking (his bit matched his chuck size so even though there was no taper, it could still be chucked.)
Each piece was remounted on the lathe and turned into somewhat of a donut shape, or call it a torus if you must. After turning, each piece was sanded on the outside and lightly on the inside where it will mate with an adjacent piece. Be careful to avoid sanding away the sawing irregularities. These pieces will become the segments. Each progressive piece was turned slightly smaller than its predecessor. Also, more wood was removed from the top of each segment than from the bottom.
The alignment holes were slightly countersunk to make inserting the dowel easier. The dowel was inserted and the segments were glued up around the perimeter, keeping the sequence. Once the glue has cured, rechuck the work to hollow it.
Denny started with a ¾” forstner bit mounted in the tailstock to begin the hollowing process. He would allow the bit to lightly find its own center, then lock down the tailstock, and advance the tailstock and bit into the work. Lathe tip and technique: remember to hold onto the chuck as it is withdrawn from the work as only a friction fit in the number two Morse taper holds the chuck (and bit) in place. Clear the shavings and redrill as needed. Denny drilled all the way up to 2” diameter with a forstner bit increasing the size in stages.
With the work still securely mounted, Denny choose the round cutter on an Easy Wood Tool http://www.easywoodtools.com/ , but other tools could be used as well. In addition, Denny ran his lathe in reverse, so he could cut on the far side of the piece and void having to position his body so far over the lathe bed. Here he cautions to measure the thickness critically since the piece will not have a uniform thickness all the way around since some of the drilling was done off center. Once the piece is hollowed, Denny moved on to the top.
The first job with the top is to turn it round, and then turn a section to fit inside the bottom. He lightly held the bottom against the spinning top to mark the diameter and turned it to size. He also hollowed the top for a nicer appearance.
The bottom was remounted and the lid was placed on top. The very top of the lid was turned and sanded. Denny says the project is a good candidate for spray lacquer.
Commentary and text by Andrew DiLorenzo