08 – Carve the Seat

  1. A Walnut Windsor Chair – Introduction
  2. The Log
  3. Transport
  4. Rough Lumber
  5. Seat Blanks
  6. Legs
  7. Arm Posts and Tapered Holes
  8. Carve the Seat
  9. Turn the Undercarriage
  10. Assembling the Seat and Undercarriage
  11. Spindles
  12. Arms
  13. Assembling the Spindles and Arms
  14. Crest Version 1 — The Form Bent Laminated Crest
  15. Crest Version 2 — The Steam Bent Crest
  16. Final Assembly
  17. Detailing
  18. Finishing a Walnut Windsor Chair
  19. Final Notes

Entry 8

Carve the Seat  –  1/1/2008

Now for one of the most interesting steps.  Carve the seat.  Change a flat slab of wood into a sculpted form that is comfortable to sit in.

This is a shield shape seat.  I find this shape particularly interesting to look at.

Traditional windsor chair construction would involve a seat made of pine or poplar.  The seat would be carved by hand using an adze, scorp or inshave, planes and chisels.  Dunbar’s book has some great pictures showing this process.

The woods that I use for chair seats include elm, walnut, cherry, mahogany, poplar and butternut.  Elm, walnut, and cherry are hard and heavy (all specific gravity of .50 or higher).  Hand tools would be tedious.  Besides, I’m used to using a right angle grinder from doing body work on cars.  So, I’ve adopted my own scheme for carving the seats that is a mixture of hand and power tool work.

I start by carving the rain gutter.  This is a v-groove that sets off the spindles and arm posts from the rest of the seat.  The long arc at the back is done with a router, v-bit, and arc/circle cutting guide.  The curve around the arm posts is done by hand with a v-gouge and mallet.

The first step in carving the seat is to draw a contour map showing the depth of the seat.  This is my guide for using the router.  I excavate the seat freehand using the contour map as a guide.  The contour steps are in 1/8 inch increments.  The picture at right shows the result of doing the contour routing.  The hood at the right is hooked up to my dust collection system but the process generates lots of dust and chips that fly everywhere.

The next step is to smooth the contour steps.  I use a coarse disk (36 grit or so) in a right angle grinder.  This step goes very quickly.  The grinder must be used with care since it will dig thru wood, even a hard wood like walnut or elm, very quickly.  I do this free-hand with regular stops to check the contour.  After doing the top, I flip the seat over and sculpt the bottom.

While doing this sculpting, I have my air helmet on to provide respiratory and face protection.  Hearing protection is also highly recommended since both router and grinder are noisy.

Once the shape is established and the bulk of the waste removed, I refine the shape with files and scrapers.  A rasp is great for doing the finish shaping of the underside and the front of the top.  Scrapers allow me to fine tune the bowl area where people will plant their rear-end.  The depth of the bowl area is a bit over 3/4 of an inch.  After these steps, I use a random orbit sander through a progression of grits (120, 150 and 240) to produce a smooth, scratch free finish.

The final step is hand sanding.  The curve at the back gets sanded to 320 or 400 grit by hand.  This is end-grain and I find that this sanding step ensures a smooth, scratch free surface that will look great with an oil finish.  The top will get final sanding later after the legs are attached.

In choosing wood for the seat, I will use boards with a knot as long as I can position the knot so it does not have any holes drilled into it.  See the right hand seat in the top photo.  These knots often have interesting, swirling grain around them that adds visual interest to the seat.  If there are cracks around the knot, I use a mixture of sawdust (walnut in this case) and epoxy to fill the holes.  When finished, these repairs look like a part of the knot.  (March, 2007)