DIY Network

Contemporary Dining Chair: Templates, Jigs, and Laminates From "Wood Works" episode WWK-507

This elegant dining chair is crafted from Bubinga, a beautiful African hardwood. The chair back is made from tapered laminates and is gracefully curved to support the lower and upper back. The solid, sculpted seat and contoured legs complement the curved back and create the illusion that the chair was carved from a single piece of wood.

In this episode of DIY Wood Works, host David Marks builds a contemporary dining chair. This simple, elegant dining chair is crafted from Bubinga, a beautiful African hardwood. The chair back is gracefully curved to support the lower and upper back and was made by tapering laminates. The bubinga stock is cut at the band saw into 1/4-inch-thick strips, then tapered, using a custom jig, at the planer. Once the laminates are planed, the back is glued and bent in a one-part bending form using the vacuum press. The two front legs are tapered slightly and joined to the seat with hand-cut joinery. The seat is hand-sculpted for comfort.

The solid, sculpted seat and contoured legs complement the curved back and give this piece a distinctive look -- as if it were carved from a single piece of wood.

Woodworkers agree that building chairs is among the most advanced and challenging of woodworking projects. This one is no exception. It requires first building a mockup, bending form, custom tapering-jig and series of templates from MDF.

Materials:

Bubinga Stock
MDF for bending form, templates and mockup
Bending-plywood for bending form
Vacuum press
Table saw
Band saw
Carpenter's tape
Clamps
Yellow woodworker's glue
Slow-setting resin glue
Straight-edge
Carpenter's pencil
Chalk
Safety glasses or goggles

Safety Alert: Always wear safety goggles or safety glasses when
working with wood, power-tools, saws, drills, routers, etc.

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	Figure I

Templates, Jigs and Bending Form

The back of the chair is made by cutting, tapering and bending six laminates. The seat (figure A) is made by edge-gluing two pieces of bubinga, then sculpting the top surface by hand. The tapered legs are joined by a combination of half-lap and mortise-and-loose-tenon joinery.

In a project this complex, it's advisable to first make up a mockup of the piece using inexpensive wood or MDF. This will help you develop and perfect the design before you begin work on the chair itself (figure B).

Bending Form

• Starting with the back-support, use a flexible strip of wood to lay out and draw a pleasing curve onto a sheet of MDF.

• Create the curved template for the support by cutting out the curve at the band saw (figure C). This template can be used to make up the back-support of the mockup. The mockup is intended only provide a general idea of what the finished chair will look like. It's an important step, however, in that it provides the rough dimensions, helps in determining the placement of the seat and legs, and allows working out the most comfortable placement of the lumbar support in the chair's back.

• With the curve of the back worked out, you can begin work on the bending form that will be used to shape the bubinga. Using 3/4-inch MDF, cut out five ribs using the curved template as a guide. Secure each of the ribs, approximately 2 inches apart, to a sheet of MDF using wood glue and nails. Cap the end of the form to provide additional strength, securing the cap also with glue and nails (figure D).

• Glue a sheet of 3/8-inch bending plywood to the curved surface (figure E), and place the assembly into the vacuum press. Once the bending form is complete, some plastic can be added to the curved surface so that the laminates won't stick to it during glue-up.

Tapering Jig and Templates

• For the back-support, the design calls for a taper that starts at the base1-1/8 inch, and tapers to 3/4-inch at the top. To create the taper, a custom jig is made to help in tapering each of the laminates by 1/16-inch. The laminates are run through the drum sander using this custom-made tapering jig.

• To build the tapering jig, use a 1/16-inch shim (figure F) to create five tapered ribs of MDF using the table saw. The green tape on the stock helps keep both the stock and the shim aligned as the cuts are made (figure G).

• Attach the tapered ribs -- evenly spaced apart -- onto a sheet of 3/4-inch MDF (figure H) using yellow glue and nails.

• Cover those tapered ribs with another sheet of MDF and fasten it in place also using glue and nails. Cap the ends of the jig (figure I) to create stops that will hold the laminates in place as they go through the drum sander.

  Tip: If you don't have access to a drum sander, you could perform the next steps by double-stick-taping the laminates onto the jig and running through a planer. If you use this method, make sure that the knives of your planer are extremely sharp.

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