Inside-Outside turning is a process in which 2 or more blocks of wood are glued together with craft paper (or newspaper) between each joint so that you can split them apart easily. Then once they are glued, the piece gets turned to a specific shape, sanded and finished. Then the glued up blank is split apart with a chisel and each block is turned 180 deg and permanently glued without the craft paper, re-mounted on the lathe and finish turned.
Follow along and I'll show you how I made this inside-outside vase with maple on my lathe.
Step 1: Gather your materials
I found a nice long stick of maple. I cut 4 blanks 1"x1"x9". These need to be square on all four edges. This required me to cut all sides of the blocks on the table-saw to ensure square.