The plank chair is made out of two boards that interlock and crisscross. There are lots of names for this chair: I’ve heard it called Viking chair, bog chair, and watchman’s chair. I learned about this chair from a jesse.hensel ‘instructable’ about building a “plank chair.”
The chair is made of two pieces of wood that interlock, and it can be taken apart for storage or travel. The exact way the pieces interlock can vary. Often the interlocking mechanism is a mortise and tenon joint, but I chose to make this chair the easier way, with two interlocking slots.
The name “watchman’s chair” is best applied to the chair that has a through mortise and through tenon as its interlocking mechanism. The tenon, or tongue, refers to the back leg of the chair, and it is narrower than the plank of the front leg. “Watchman” refers to one of the functions of this simple design. Because of the narrow back leg, the chair is stabilized by the sitter’s legs, so if a watchman fell asleep in it, the chair would probably tip over and the watchman would wake up. That is, the chair is programmed to wake up a dozing watchman.
The chair’s dimensions can vary widely. Search the web for “plank chair” to see the wide variety of shapes and sizes that have been made. The most important dimension has to do with the seat. If the seat is too long and the rear leg is too short, the leverage created by the sitter’s weight can cause the back leg to lift off the ground.
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Step 1: Materials and Tools
0.25” x 7” x 2.5”
0.25” x 7.5” x 2.5”
Paint or stain or finish or your choice
Scroll saw -- or any small saw for cutting wood and slots
Ruler or tape measure
Step 2: Seat and Back Leg
The seat and back leg are made from the 7-inch-long board. Cut a slot ¼” wide 2.5” from the end of one board. The slot should extend half the width of the board. With the lumber I was using, I cut a slot 1.25 inches deep. The shorter 2.5-inch end of the board beyond the slot will be the seat. The rest of the board will be the long back leg.
Step 3: Back Rest and Front Leg
The back rest and front leg are made from the board that is 7.5” long. Cut a slot 0.25 inches wide 1.5 inches from the end of the board. This 1.5-inch end beyond the slot will be the front leg.
Step 4: Assemble Two Pieces
Fit the slots together to make your chair.
Step 5: Epilogue
Decorations are often carved into the backs of these chairs. The chairs can also be painted in school colors: one plank one color, while the other plank can be painted the second color.
If a child outgrows playing with dolls, the watchman’s chair can be used as a stand for a cell phone.