Carving the Seat Contours
Now you are ready to shape the seat’s contours. I’ve seen many methods for forming these recesses, but as a guy who does a lot of chairs, I find my method to be the most efficient.
First, I make a template out of thin plywood that helps contain the shape of the contours. There is a template pattern for this chair’s seat above. Then I lay out a series of lines on the chair blank that locate the areas of the seat where the depth of the contours flow from one depth to another. Then I start machining the shape with a handheld grinder, as shown in the photo sequence at left. I check and monitor the depth of my work using a straightedge and 6″ metal rule.
I rough out the shape with a grinder, then switch to an abrasive wheel that mounts on the same tool. I continue to shape the contours, completing the process with scrapers and rasps and finishing with a handheld disc sander.
By using the template and working to predetermined rough depths, you will get identical-looking shapes on your seats. As I mentioned earlier, these seats are really important to the overall look of the chairs, so take your time and get the coutours right.
With that step in the rearview mirror, you have to cut the perimeter shape of the seat. Mark the shape using a template, and step over to your band saw to make your cut. Be sure to cut to the outside of the marked line — then step to a disc or horizontal belt sander to sand exactly to the line. I use a handheld disc sander, hand sanding with a sanding block to complete the edge.
I use a 1/4″ bearing-guided roundover bit to shape the top and bottom edges of the seat, staying clear of the leg notches. A touch more hand sanding, and then you can set the seats aside until you start to assemble the chair.