Segmented Bowl Bark Accent

SEGMENTED BOWL - WITH A - BARK ACCENT

Segmented cherry bowl with walnut splines between the segments and a bold accent ring of RING Rolland K. Stratton oak bark glued onto a solid-wood support strip.

often harvest green wood, especially I have always been drawn to using cherry segments and walnut splines, after a storm. I saw down the center of bark in wood designs. In my early followed by the bark ring, and topped Ia log, remove the pith, and then seal stages of turning, I discovered how with a ring of cherry segments only. the ends. After the wood has dried for a to make bark-edged bowls by har- year or so in a shed, I bring a bowl blank vesting the wood when the sap was The base into the shop. Sometimes the bark has not running so the bark would hold For the example project shown in the begun to separate from the sapwood. I firmly. I now know that thin cya- opening photo, I turned a bowl base carefully drive thin maple shims into the noacrylate (CA) glue works well to of cherry wood with interesting grain. edge of the bark to remove large chunks secure loose bark. I’ve also learned After cutting a circle, I mounted the from the sapwood. Initially, I did this how to take a light cut from the rim wood onto the lathe, centered on a so the bark would not fly off during the of a bowl to its base to minimize piece of fiberboard and held securely beginning stages of turning. Now, I use bark fragmentation. with the point of the tailstock. I the bark as accent rings in segmented In this article, I’ll show how I added turned it round with a tenon on the woodturning (stack lamination). It is an a bark accent ring to a segmented bottom and sanded the base (Photo 1). exercise in playfulness—the patterns and bowl. This design starts with a solid With the tenon mounted in the combinations are endless. base and is built up with two rings of four-jaw chuck, I turned a recess ⅛"

JOURNAL ARCHIVE Form the bowl’s base CONNECTION or turners who have never tried segmented turning or for those F who would like a refresher on the basic concepts, here is a simple, easy approach to turning a segmented Turning Your First bowl. This quick, accurate method will For further guidance acquaint you with the fundamentals of segmenting, which you can then apply to more complex pieces. The SEGMENTED bowl presented here makes use of a solid layer of wood for the foot and Jim Rodgers four progressively larger rings, each BOWL one comprising multiple segments cut on cutting segments at predetermined angles. Segment-cuttin As you would imagine,g segmentedsled projects require careful attention to creating a blank prior to turning. The table saw is my preferred tool for cutting segments, and a sled with a fence set at the correct angle is the best way to produce identical and gluing them segments. Some time invested up front creating a good sled will help you far into the future. I recom mend making and using a Wedgie Sled, a simple fixture designed by- renowned segmented turner Jerry Selecting wood Bennett. Plans and instructions for You will need to determine which building this sled, as well as helpful wood species to use; I had some very videos, can be found at Jerry’s Make a drawing into rings for stack dry Eucalyptus cut a few years ago website, segeasy.com. Regardless of Make a full-sized drawing of your from a friend’s yard. Mill the wood the sled design you choose, the goal bowl on graph paper with your to the desired thickness you want is to be able to cut desired angles desired profile. This drawing will help for each level, or ring. I chose ⅝" accurately and with repeatability. you determine the ring diameters and (16mm) thickness. It is important thicknesses as well as the segment that you select wood that is thor sizes required. Allowing for extra wall oughly dry, with moisture content thickness now will help you mini JOURNAL ARCHIVE of six to twelve percent. Using - mize any problems you might have lamination, see Jim CONNECTION green, or unseasoned, wood intro later in aligning the rings or turning- Jim Rodgers has written duces a greater likelihood of wood the bowl. Next add horizontal lines to previously in Part 1: Cut Accurate Segments American - Woodturner movement, which will cause indicate the foot and ring thicknesses, on segmenting. His 2005 article on cutting glue joints to fail. based on the thickness of the wood accurate segments (vol you will be using. Add a centerline to 20, no 4, page 24) offers Segmented Plan your bowl the drawing and number each level, helpful information, Turning Unlike other kinds of wood or ring, of the bowl from the base School including an alternate turning, segmented projects upward ( - sled design and tips on gluing segments into24 By Jim Rodgers require detailed planning of Figure 1 Note that drawings). made with Rodgers article, American Woodturner Winter 2005 rings. AAW members can access all past the piece you wish to create. For sophisticated software or using journal articles online at woodturner.org. this project, I decided on a small trigonometry functions will render popcorn bowl that would fit in more accurate results, as a simple your lap—about 3" (8cm) tall by 7" two-dimensional drawing cannot (18cm) diameter. account for the three-dimensional aspect of the bowl’s curvature. This is 18 why allowing for extra wall thickness “Turning Your 18_SegmentedBowl.indd 18

American Woodturner October 2015 First Segmented 9/9/15 2:04 PM 1 2 Bowl” (AW vol 30, no 5, page 18). AAW Begin by turning the base of the bowl, Chuck the blank by the tenon and turn what with a stub tenon for chucking. will be the inside bottom surface. Flatten members can access all past journal the rim using a sanding board to prepare it articles online at woodturner.org. for gluing the first segmented ring.

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First segment ring

3 4 5 The table saw cutting jig makes perfect 30° Use two hose clamps in tandem to The lathe’s tailstock applies clamping segments from strips of cherry wood. glue up the first segmented ring, pressure for gluing the bowl base to the with walnut splines between the first segmented ring. cherry segments.

(3mm) deep in what would become up to the full circle’s 360° (Photo 3). To each piece and spline down perfectly the inside of the bowl, with an outer protect my fingers and prevent kick- flat. Finally, I tightened the ring clamp edge 1" (25mm) wide and perfectly back, I used the eraser end of a long to full tightness (I use a 5⁄16", or 8mm, flat. A sanding board can be a useful pencil to hold the workpiece. To avoid driver in a drill with preset torque) and tool on this last step. This flat outer problems during glue-up, I lightly wiped off the excess glue. edge will become the foundation for hand-sanded any frayed edges. the segmented bowl rings. I also totally To saw the twelve walnut splines, Assembling first two rings sanded the inside center of the base of I used a square-cutting sliding table. After leaving the glue to set for twenty the bowl (Photo 2). Again, I used a long pencil with eraser minutes, I sanded one side of the ring to hold these down as while they were perfectly flat to prepare it for gluing Cutting segments being cut. to the bowl’s base. I made sure it was I measured the bowl base diameter, in perfectly centered and then used the this example 7" (18cm), and calculated Gluing segment rings lathe’s tailstock to press the assembly its circumference, 22" (56cm). Since Even though my work surface is against a disk mounted in a chuck on my segment rings were to comprise covered with heavy scrap cardboard, the lathe’s headstock, and wiped off twelve segments, each segment would I always put wax paper on the card- any excess glue. Now the first level of have to be 1.83" (46.5mm) long: that’s board when I glue segments. First, the bowl could dry in place with the the circumference divided by the I assembled the cherry pieces and clamp on (Photo 5). twelve segments. walnut splines without glue and placed After the glue dried, I removed the The design I was making also calls an extended hose clamp (that’s two assembly from the lathe and the hose for walnut splines between the seg- ordinary clamps hooked in tandem) clamp from the first segment ring. I ments and they are 0.2" (5mm) thick, around the segments. I dry-fitted the then remounted the base tenon in a so I needed to cut the actual segments pieces, clamped them, and made sure chuck and used a sharp gouge to clean 0.2" less than 1.83", or 1.63" (41.5mm) they fit the base of the bowl-in-process up the face of this first ring. To be sure long. I used digital calipers to set the (Photo 4). the face was perfectly flat, I held a large stop blocks on my table saw cutting jig I spread wood glue on all mating board with an 80-grit sandpaper pad and checked the pieces to ensure accu- surfaces, placed the clamp around the against the ring as it spun on the lathe. rate measurements. segment ring, and gently tightened Now I could remove this bowl-in- I set up my table saw cutting jig, them together. Using a damp rag, I process from the lathe and determine which was pre-set for the 15°-angle wiped off the excess glue, then cen- the length of the segments needed to needed; that’s 15° on both ends of the tered the hose clamp in the thickness create the second ring. I do not engi- segment, so the workpiece needed to of the wood and tightened it medium- neer my segmented bowls by sketching be flipped after each cut. The result secure. Next, I placed the ring on a a graph-paper design. I have the idea was twelve 30° pieces, which added flat surface and used a hammer to tap in my head and work out the math for

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30_BarkRing.indd 31 1/7/16 12:30 PM each level as the project progresses, Second segment ring one ring at a time. For the second ring, I used a spare segment to visualize a step with a safe overlap to ensure ample wall thickness (Photo 6), and I determined that the next ring’s cherry segments would have to be 2.03" (51.5mm) long, again with 0.2"-wide walnut splines between them. After the second ring was assembled 6 7 and glued like the first one, I sanded Eyeball the overlap between the first and Rotate the second segmented ring to second rings and measure the width of the position the walnut splines, then glue and one side and glued it to the first segments needed. clamp it as before. segment ring, situating the walnut splines in the center of the cherry segments (Photo 7). After the glue dried, I turned both of these segmented rings Harvest and cut the bark nearly to the wall thickness of the fin- ished bowl. This step and the resulting dimensions are critical.

Bark accent ring The third ring of this design carries the oak-bark accent and is what makes this project unique. The bark is too fragile 8 9 to stand alone, so it must be glued to To harvest bark from an oak slab, drive Joint one edge of the bark, saw it into strips, solid-wood segments (of cherry in this narrow maple wedges between the bark and sand the inside surface lightly to flatten case). I consider whether this accent and the wood. each strip. ring will have bark on the outside only, or whether there will be bark on both the inside and outside of the bowl. Make a segmented ring with bark For this example, I decided to have bark on both sides, so I measured the bowl’s wall thickness and cut a piece of cherry thin enough so that with bark glued on both sides, it would equal this wall thickness. If the bark accent ring is only for the outside of the bowl, the cherry strip would need to be corre- spondingly thicker. To harvest good bark, I bring a long 10 11 dried slab into the shop. I match the (10) Clamp the bark accent strips to the cherry primary wood of the bowl to the bark support strip. Keep everything in line by I want to use in the accent ring—in clamping one strip at a time. this example, I chose oak for its dark (11) After cutting the glued-up bark strip into color and interesting texture. I use angled segments, glue the segments into an accent ring using hose clamps for pressure. maple splines a bit less than ⅛" thick and drive them between the bark and (12) As before, use the tailstock to apply gluing pressure when attaching the bark the sapwood to slowly lift off the bark accent ring, as well as the rim ring. without cracking it. The bark looks 12 like a tortoise shell (Photo 8). I joint one edge, then set the table saw rip

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fence slightly wider than the cherry tightened the ring clamp (Photo 11). support strip and saw the bark into After allowing the glue to dry for an strips (Photo 9). hour, I sanded one face but left the Variations Each strip must be carefully exam- clamp in place. I spread glue on the ined for major cracks, splits, and dis- sanded face and matched it to the tortions. I cut off the ends that have rim of the bowl-in-process. curled in the drying process, sand Once the glue began to set, I trans- the inside of each bark strip on a belt ferred the clamped ring to the lathe sander with 80-grit paper to flatten it and used the tailstock as a pressure and remove the softest inner layers, clamp (Photo 12). 13 then square up the strip ends on Turning deeper into the bark ring’s lower half will result in a scalloped pattern. the table saw. I coat both the cherry Top ring support strip and the back of the bark While the glue was drying on the strips with wood glue, then line up bark ring, I measured the size of the the bark to the cherry and clamp the final, solid cherry ring, whose seg- pieces together. To minimize slippage ments had to be 2.39" (60.5mm), it is best to glue the bark on one side at and cut them using the sliding table a time (Photo 10). saw jig. As always with this process, I After this glue dried, I lightly sanded clamped them without glue to confirm 14 both edges of the bark segment strip that they were the right size before The bark accent ring on this bowl appears on the outside only. to remove any glue and also any bark gluing the segments into a ring. After ridges. The strip needs to sit square this final ring has dried for an hour, and flat in the table saw cutting sled, I sanded one face flat. I reversed the paper bag. When I get to the 220-grit so I also lightly sand the bark faces to bowl-in-process to true the bark-faced abrasive, I begin sanding forward and remove any major ridges. If you don’t ring and sanded with the sanding backward and wipe the wood clean have a sliding table saw jig, you could block to prepare it for the final glue-up. between grits. cut these segments on a chop saw set at With the final ring glued to the bark- For a finish, I like to apply a coat of 15°, but watch your fingers. faced ring, I made sure the joints were natural Danish oil and wipe it dry with Once again, I carefully checked the staggered and then moved the entire the lathe running. I then wet-sand diameter of the bowl-in-process and assembly to the lathe and used the in each direction with 220, 400, and cut the bark-faced segments so that tailstock for clamping pressure. 1000 grit (paper bag), apply more coats the bark would extend slightly beyond of oil, and buff to a satin finish. the bowl’s inner and outer surfaces. I Turn and finish clamped these pieces without glue for It is best to leave the bowl-in-process Rolland Kipton (Kip) Stratton, of Otego, a final alignment check. I made the overnight so the glue has time to dry New York, is a retired pastor with the United Methodist Church. He has attended regional segments slightly larger than needed thoroughly before turning the bowl and national woodturning meetings and so I could trim to perfect alignment. to its final shape. Turn the bowl as you helped found a local woodturning group. Since this bowl was now 8¼" (210mm) would any other segmented bowl. During the winter months, Rolland teaches in diameter and 25.9" (658mm) in To create a different pattern on the woodturning in Yuma, Arizona. Being circumference, I cut the bark segments bark accent ring, you could carefully playful in his woodshop helps Rolland keep 2.15" (54.5mm) long. turn into the bark ring’s lower half balance in his life. I use a generous amount of glue to reveal the cherry layer. This will on bark-faced segments and, as with produces a scalloped edge on the bark the solid-wood segments, clamp the accent ring. As noted, another varia- bark-faced ring in stages. I began tion can be produced by gluing bark to by clamping lightly with the con- only one side of the core strip (Photos nected hose clamps, then wiped off 13, 14). the excess glue and tightened to a I usually sand through the grit medium level. I then placed the ring sequence: 100, 150, 220, 400, and on a flat surface, hammered all the finish at 1000, which means a final segments into perfect alignment, and sanding with the surface of a brown Bark accents Rolland’s playful oak birds.

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