Turning an Old Spalted Oak Burl

I got this large old oak burl from a customer who wanted a bowl. The burl was oddly shaped with a large depression in the top and it was gnarly, exactly the type of burl I love to turn. The gallery of images below shows the burl and the process of turning it. It was not obvious how to trim and attach the burl to my lathe. I used this old burl as a demo piece in my wood turning classes to challenge students to visualize a bowl from this burl and to decide how to proceed. It was clear that the depression had to become the inside of a bowl. This required careful centering on the lathe so the bowl wall would be solid. The series of images are arranged in order and shows the process better than I can describe it. The tricky part was filling in the depression/hole with a material that would permit the attachment to the lathe. I used an epoxy sculpting clay to fill and smooth the depression and glued several pieces of plywood to the set up clay to provide a level and stable platform for attaching a drive. I used a 2.5" Elio drive with a Morse taper and a live center in the tail stock to turn the profile of the bowl. A 4.5" diameter tenon was turned on the bottom. There was decay in this area so I used generous amounts of thin CA glue and fine ground coffee to fill these voids and to stabilize the base. The turning was slow but worked out nicely. Since the wood was dry I sanded and oiled it right away. I use a 50:50 tung oil/citrus solvent mix (Real Milk Paint Company) for sealing and a beeswax/walnut oil for the final finish. The bowl came out nicely with great colors and spalting patterns.