How to Make Chairs From Sheet Plywood

Cut Plywood

• 1

  Place one long edge of the plywood against the fence on the table saw. Rip the plywood by cutting it in the same direction as the surface grain into two 24-inch-wide-by-96-inch-long sheets. Set one sheet aside for a future project.

• 2

  Cut the remaining sheet of 24-by-96-inch plywood across the grain to make three pieces that are 24-by-24-inch, 20-by-24-inch and 24-by-52 inch.

• 3

  Use a carpenter's pencil to label the rough side of the 24-by-24-inch piece as the "seat." Label the rough side of the 20-by-24-inch piece as the "back." Set the seat and back pieces aside.

• 4

  Place the 52-inch edge of the plywood against the fence on the table saw. Rip the 24-by-52-inch piece into one piece that is 8 inches wide and one piece that is 16 inches wide, cutting in the same direction as the surface grain. Set the 16-by-52-inch piece aside for a future project.

• 5

  Rip the 8-by-52-inch piece along the 52-inch edge to make two pieces that are 4 inches wide. Cut each 4-by-52-inch piece into a 4-by-4-inch piece and two 4-by-24-inch pieces. Set the 4-by-4-inch pieces aside for a future project.

• 6

  Label the 4-by-24-inch pieces "front, rear, right side and left side." Set the saw to a 45-degree angle away from the miter fence. Lay the wood smooth face down. Miter along the 4-inch edge at each end of each board.

Assemble Seat and Skirting

• 7

  Position the 4-by-24-inch boards in a square on a flat work surface on the 1/2-inch edges, with the mitered edges touching. Apply bar clamps to hold the pieces together. Use a carpenter's square to ensure that the boards all meet at 90-degree angles.

• 8

  Measure the diagonals. Adjust the clamps and reposition the boards until the diagonals measure the same distance, or cut and miter new boards to the correct measurements.

• 9

  Remove the clamps, apply carpenter's glue along the mitered edges and reassemble the square as before. Reapply the clamps without using so much pressure that you squeeze out all the glue. Wipe away any excess and allow the glue to cure overnight.

• 10

  Face the "front" of the square frame. Mark screw positions 1/4-inch from each corner of the front of the square frame, 3 inches apart vertically. Drill 1/16-inch diameter pilot holes through the front and into the sides at all four screw positions.

• 11

  Switch to a countersink bit and bore straight into all the holes 1/4-inch deep. Secure the front piece to the sides using 1/8-inch-diameter-by-1-inch-long wood screws.

• 12

  Turn the square around and repeat the previous two steps to secure the rear piece to the side pieces, creating the support skirting for the chair seat.

• 13

  Lay the 24-by-24-inch plywood seat smooth-side up on top of the support skirting so all edges and corners are flush.

• 14

  Drill 1/16-inch diameter pilot holes through the seat and into the skirting every 2 inches, beginning 1 inch from the right front corner of the side facing you. Countersink each hole and secure the seat to the skirting using 1/8-inch-diameter-by-1-inch-long wood screws.

• 15

  Use a chalk line to snap diagonal lines from the right-front corner to the back left corner, and from the left front corner to the right back corner.

Add Legs and Back Supports

• 16

  Lay the 2-by-4-by-40-inch boards on their 4-inch faces. Mark one end of the board "A" and the other end "B."

• 17

  Measure 20 inches from the "B" end and draw a line across the 4-inch face of each board using a carpenter's square. Mark the center point along each line, 2 inches from each long side on the 4-inch face of each board. Label each point "C."

• 18

  Stand at the "A" end of each board. Label as "D" the 2-by-4-inch end of each board facing you. Label the side of the board to your right as "E" and the side of the board to your left "F."

• 19

  Return to the line passing through point "C" between sides "E" and "F." Cut along the line from side "E" to point "C."

• 20

  Mark a point along the 4-inch face of the board at the "A" end, 1 inch from side "F" and label that point "G."

• 21

  Lay a yardstick between points "C" and "G." Draw a line along the yardstick from "C" to "G."

• 22

  Cut the angle from point "G" to point "C" to create the back legs and the angled back supports.

• 23

  Stand the 23.5-inch pieces of 2-by-2-inch stock lumber on end, 22 inches apart. Have a helper hold the back leg/back supports 22 inches apart and place the seat on top, skirt-side down.

• 24

  Adjust the front and back leg positions until the front legs sit flush in the corners of the frame. Secure the front legs to the seat using 1/8-inch-diameter-by-2-inch-long wood screws.

• 25

  Face the back of the chair. Drill two 1/16-inch-diameter pilot holes 3 inches apart vertically, 21 inches from the floor and 23 inches from the floor. Countersink the holes and secure the back legs to the skirting support frame of the seat using 1/8-inch-diameter-by-2.25-inch-long wood screws

• 26

  Face the front of the chair. Lay the 20-by-24-inch piece of plywood labeled "back" with the 24-inch edge running left to right across the back supports, with the smooth side facing you.

• 27

  Drill 1/16-inch-diameter pilot holes along each 20-inch edge every 2 inches, and 1/4-inch from each 20-inch edge. Countersink each hole and secure the back to the supports using 1/8-inch-diameter-by-1-inch-long wood screws.

• 28

  Round all edges and corners using a coarse belt on your sander. Sand at a 45-degree angle. Wipe away the sawdust and seal the entire chair with three to five coats of clear wood sealant, drying each coat 24 hours before applying the next.