GEORGE TROY HURLBURT                            georital@hometelco.net

DEMONSTRATION OF SEGMENTED BOWLS PRESENTED TO KANSAS WOODTUNER CHAPTER OF AAW IN TOPEKA, KS  - -------WRITTEN BY JIM BRYAN

George Troy from Galva, KS demonstrated his method of making segmented bowls and other turnings. Ed Provost who you all know has made hundreds of segmented turnings with intricate designs told me after the meeting that it was the best demonstration on segmented turnings he had ever seen. George was a good teacher in that he went through things slowly and patiently for those of us who didn’t have much knowledge about the process.

 SUPPLIES – George uses the following: Urethane oil from craft supplies as a finish coat. He uses Meade tablets with ¼  inch square graph paper for drawing shapes by hand. He uses an adjustable triangle obtained from Office Max to set up his table saw cutoff tool jigs. George also uses “Smart Sketch” a computer program to draw shapes/bowls etc. and prints them off on ¼ inch square graph paper. In other words, the computer prints both the graph paper and the shapes George draws. George can draw ½ of a round object and the computer will duplicate the identical shape, to complementary make a bowl, vase, etc. George does his gluing using Titebond  II on wax paper without using clamps.

 COMPUTER DESIGN – Using the Canvas drawing program (not a CAD program) George is able to use a mouse to draw shapes until he finds one side of a bowl he is satisfied with. The computer duplicates the same form/shape on the opposite side of the bowl George can manipulate the shapes as to height, etc. By printing out the shapes on the graph paper style background, it is easy to measure or use the computer to tell you the outside diameter desired of the rings that will be glued up from individual segments to make the bowl. The program allows the user to determine the size, angles, etc. needed as well as the number of pieces, the number of rings to make a bowl, vase, etc. George also provided a handout and samples of exactly what the drawings should look like prior to beginning work. As George said, you can either do it with graph paper and a pencil or you can do it with the computer. The end result should be identical.  A copy of George’s handout is included with the Newsletter.

 SET-UPS FOR CUTTING SEGMENTS  - After determining the number of segments per ring, i.e. 12 segments, each of which would have an included angle of 30° requires setting the table saw cutoff tool at 15° because each side of the segment is cut at a 15°angle to make a total of 30°.  The adjustable triangle is used to set up a home made cutoff tool made by cutting a wood runner to fit into the table saw groove with a 15" or 16" long 1" x 2" attached to it set up with the adjustable triangle at 15°. In making the setup to be used in the tabletop groove to the left of the blade, use a 1" x 2 " long enough so that at the correct angle it will extend 4" to 5" to the right of the blade. A stop or block of wood is clamped to the backer board portion of the setup to assure appropriate width of each segment. The width of the segment is determined either by using the computer or by using the formulas on the handout based upon the size/circumference of the intended finished product. Assuming segments of 1 ½" widths were desired, the block would be set so that the wide part of the segment would be against the back of the pushboard. The segment would be first cut off for length at the 15° angle, then flip flopped 180° and cut again to provide matching 15° angles on each side. After 12 are cut, test to see if this made a good circle or if it was off. Depending upon whether the heel or the toe was too long or too short the jig is adjusted slightly and additional test pieces cut and additional adjustments made until the jig is cutting segments at the perfect angle needed. At that point the jig is screwed together in a fashion it is permanent. It is marked with the angle it provides and saved for use in the future. George uses a pencil with the eraser down against the segment which he uses to remove it from the blade after it has been cut. He pushes the stock up against the blade so that it is cut clear through but does not push it past the blade rather backs the cut off tool backwards and uses the pencil and eraser to move the just cut segment to the right away from the blade. A certain amount of trial and error is involved in getting the set up completed, but once the set up is done it will cut perfect segments consistently.

 GLUING – George takes the segments for a ring, lays them out on waxed paper, puts a good amount of glue on one side of one segment, rubs it together on a flat surface on top of the waxed paper to the adjoining segment and after both sides are thoroughly covered and the glue squeezed out, it has a reasonable amount of hold or grip immediately. George continues around until he has a half circle completed, then he uses a straight edge to check to be sure he has exactly one half of a circle, if not, he will let the half circle dry and when it is sufficiently dry to do so will take it to a disc sander and sand slightly to make the half circle a perfect half circle. The two half circles are then glued together to make one segmented ring.  George does not use any type of a clamp to hold the segments together or the rings together. There is a certain amount of unevenness due to the wood not being 100% consistent in thickness as well as minute movement during the gluing/drying process. It is reasonable to glue up all rings for a particular project and leave them to dry. It is also reasonable to glue the rings individually to bowl bottom one at a time using the lathe tailstock as a clamping device and then turning successively the faces left after the gluing process to bring them flat. George puts chalk on both ends of his half circle before using the disc sander. The chalk helps make certain when a slight amount has been taken off throughout and made everything straight/flat. A thickness sander or disc sander makes at least one face of a ring flat prior to gluing.

 TURNING/SANDING- George uses a waste block glued to the bottom of the bowl he will turn. After gluing to the waste block, he turns the bottom of the bowl flat – checking with a straight edge to make certain it is flat at all areas where the first ring will be glued. The first ring that will be glued to the bottom is then flattened on one side by rubbing it on sandpaper on a flat surface or by running it through a thickness sander or by holding it against a disc sander. If available, a thickness sander is probably the fastest and most accurate method with the disc sander having the most risk of removing too much and/or ending up with one side of the ring thicker than the other. The thickness sander of course could be used to flatten both sides of the segmented ring. If both sides are flattened then one can glue up the entire project and clamp it all at one time. If only one side of the ring is flattened by sanding, construction requires gluing the flat side to the flat surface of the project on the lathe, letting it dry, turning the outside surface flat again, attaching the next segment, etc.. On shallow bowls all segments can be glued up before the turning process starts. On vases and deeper bowls it would make sense to turn at least the inside to a general smoothness as the rings are built up to avoid having to try to turn the rough edges in a deep bowl or vase. A catch can ruin an investment of considerable time.

 George turns his bowl after gluing up the segments and because it is all face grain is able to get a very smooth cut and quickly reduced the ragged edge looking object to smooth flowing lines with a minimum of time and effort. George uses "Deft" on some of the bowls and urethane oil on salad bowls. He uses walnut, oak, paduak or whatever scraps he can obtain. One of the nicer aspects of doing segmented type work is that often times the fancier exotic woods used are available at little or no cost because scraps work as well as wood purchased solely for a particular project.

 Overall, George Troy gave a very excellent presentation of a difficult subject. Some experts put on a show that makes it obvious that they really are experts, but at the same time go through their presentation so quickly that novice and intermediate turners don't get the same benefit as when the true teacher goes through slow enough and takes questions so that everyone understands the principles and tips being provided. There will be several members producing segmented work they would have never tried without George's help.                        

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