Turning is probably the most technical operation in chairmaking. I've found that by modifying a 3/8" gouge with the "Irish grind" that many bowl turners use, I can do all my roughing-out work with a single tool (photo D). After rounding the octagonal stock, I use a marked "story stick" as a pattern. With the lathe spinning, I mark the mortise locations on the leg blank and also the coves and beads for the finial. I then make scoring cuts with the parting tool and, if needed, the calipers, although I find by this time that eyeballing the cut saves time and is usually just as accurate as the calipers (photo E).
With a smaller 1/4" gouge and the skew chisel, I can do all my finish cuts. For the detail work on the finials, I make a clean cut to eliminate any need for heavy-grit abrasives (photo F). I often make the final cut with the skew. The shearing action of this tool leaves a smooth surface, eliminating much of the need for sanding. I avoid the skew, however, if the grain is at all figured because it tends to lift and tear out the fibers.
I start sanding the turned parts with the finest grit possible, usually 180- and then 240-grit with the lathe turning. I then turn off the lathe for a final with-the-grain sanding using 240-grit. I try to preserve the turned detail, which is easy to lose during the sanding process. For parting off, which I postpone until after the final finish is applied, I make a clean final cut at the headstock end, then let the piece drop into my hand while the lathe is still spinning (photo G).
Although it's unorthodox, I've found pre-finishing the pieces on the lathe effective (photo H). I use a tung oil finish, giving each part at least two coats before assembling the chair. Pre-finishing makes for easy buffing, ensures a good buildup of finish, and leaves a lot less work to be done after assembly. I cut all mortises and tenons after this initial oiling, so I don't have to worry about getting oil on the gluing surfaces.
I've added a foot clutch to my lathe, which speeds up production time considerably. A pedal on the floor lifts the hinge-mounted motor by way of a rod, taking tension off the belt. With the belt loose, I can stop the lathe in an instant using an outboard handwheel without turning the motor off. This lets me examine a turning in progress or check the piece between sanding grits for defects and scratches. I power-sand as much as possible using a 3" foam-cushioned sanding pad and an air drill. The foam cushion eases the aggressiveness of the abrasive, which means fewer scratches and less work.