Step 1: I used two 12”dia x 1” Sapele blanks: On one blank attach a faceplate (Figure 1), then use double-sided tape to hold the two pieces together (Figure 2). I then drilled four holes through and bolted the blanks together (Figure 3).
Step 2: Using a ½” bowl gouge, I turned both blanks to the same diameter (Figure 4). Then with a 1/8” parting tool, I cut a ring out of the centre. Again, using the bowl gouge to profile the hole to create a shoulder over the neck of the vase (Figure 5). The doughnut piece would need to split in half to fit around the neck of the vase and then be bolted back together. I marked-out where the bolt spigots would go and then cut these out on the bandsaw (figure 6).
Step 4: I then drilled 10mm holes in the other blank and inserted T-nuts (Figure 10). I cut four rods from a length of 8mm threaded bar, which can be easily adjusted to fit the vase into the jig (figure 12).
Step 3: I re-attached the blanks onto the lathe to steady the piece for horizontal drilling the spigots (Figure 7). I attached the collar to the vase to check the profile (figure 8). I considered this to be too loose to grip the vase sufficiently without damaging the existing surface finish, so I lined the ring with pipe insulation, which provided a better grip on the vase (Figure 9).
Figure 1: Blank with faceplate
Figure 2: Blanks prepared
Figure 3: Blanks bolted through
Figure 4: Turn to round
Figure 5: Cut out centre
Figure 6: Mark out spigots
Figure 7: Horizontal drilling spigots
Figure 8: Collar attached to vase
Figure 9: Lined with pipe insulation
Figure 10: T-nuts
Figure 11: Threaded bar
Figure 12: Adjustable jig
Step 5: The vase was adjusted to find the best centre and drilled with a 25mm Forstner bit (figure 13). Then the vase was hollowed out using 3/8” bowl gouge (figure 14).