Segmented wood bowls are made from multiple blocks of wood in contrasting tones. The blocks are stacked together, turned, cut and assembled into a bowl shape. The way you layer the different tones of wood creates patterns in the finished bowl. The design process for making a segmented bowl is more complex than for making a bowl from a single block of wood, but the distinctive segmented look can't be replicated any other way. Woodworkers who enjoy detail-oriented work will find making a segmented bowl a rewarding project.
Plan out the design for your bowl with a pencil, ruler, paper, and protractor. The design of a segmented bowl is based on the geometry of a circle. Start by making a sketch of the bowl you want to create, showing the shape and the pattern of the wood segments.
Draw a circle to represent one layer of wood. Decide on how many layers of wood you will use for your bowl and the number of segments in each layer. For example, a simple checkerboard-patterned bowl might consist of five layers of wood with ten segments in each layer, with the light and dark segments of each layer alternating. Divide the circle by the number of segments to determine the angle of each segment in the layer. A bowl with ten segments would require a 36-degree angle for each segment, or 360 degrees divided by 10.
Prepare the base of the bowl from a circle of wood, light or dark-toned, cut from a circle drawn to the largest possible dimensions within the 1-by-5 wood block. Cut out the circle with a bandsaw.
Cut out the shapes for as many rings as you desire, alternating light and dark segments of wood to make the desired pattern. Draw a circle on each wood block you plan to use, just as you did for the base of the bowl. Cut the wood into the desired number of segments with a table saw.
Dry-fit the layers of segments. Make sure they fit snugly against each other and are arranged the way you want them. Measure the dimensions of the dry-fitted bowl against the desired dimensions of the finished bowl to determine how much wood needs to be carved away.
Glue segments and layers together with wood glue, starting from the top layer down. Do not attach the base yet. Let dry.
Fit the stacked cylinder of segments onto the wood chuck. Rough-turn the cylinder to smooth out the edges and attach two wood tendons to the ends of the wood chuck to hold the cylinder in place.
Measure and mark the maximum exterior diameter on the cylinder and turn the outside of the bowl to that mark, contouring and shaping the sides on the wood chuck as desired.
Measure and mark the desired maximum interior diameter of the finished bowl. Remove the tail stock from the wood chuck and drill out the maximum amount of material to the maximum diameter point on the interior portion of the bowl. Turn the cylinder on the wood chuck to hollow out the interior. Remove from the wood chuck.
Hollow out the base circle to fit against the tendon at the base of the cylinder using the wood chuck. Return the cylinder to the wood chuck and mount the cylinder to the base. Glue in place, but do not remove from the wood chuck.
Sand the outside and inside of the bowl as desired. Apply finish or varnish to the bowl as desired.
When turning, make sure the orientation of the wood grain is always the same for each segment.
To make the segments secure while the wood glue dries, hold the assembly in place with clamps or rubber bands.