To make the big turning blank, I glue up four pieces of 16/4 poplar with 3⁄4-in.-thick pieces of pine as filler; this creates a blank that yields four shelves. The lathe’s drive center and live center leave their marks in the filler pieces instead of in the shelf wood. And when I split the forms apart, the soft pine filler protects the poplar shelf wood from damage.

Make the blank 2 in. longer than the finished shelf will be. Start by cutting the poplar pieces to length, and jointing two adjacent faces square to each other; these will be the glue faces. Next mill three pine filler pieces—two narrow ones and one wide one. And cut a strip of brown kraft paper to go in each glue joint.

The blank gets glued up in stages. Before you begin, assemble the blank dry and mark the layout. I use a…