Intro: Modern Plywood Chairs - 2 Chairs,1 Sheet of Plywood
Check out the video for further details!
Inspired by the one sheet of plywood challenge put on by the Modern Maker Podcast I built these two modern/minimalist style chairs from one 4x8 sheet of baltic birch plywood. I actually had this design drawn up a few months ago, but I decided to hold off when I heard about the challenge. These chairs are a similar style to the modern plywood dining table I built, and they match up perfectly.
Things I used:
1 4’x8’ sheets of 3/4” Baltic Birch Plywood
Bessey Clamps - http://amzn.to/2CZwF0n
Glue - http://amzn.to/2Dyej7N
Glue Bot - http://amzn.to/2Dyej7N
Incra Miter Gauge - http://amzn.to/2Dyej7N
Angle Finder - http://amzn.to/2Dyej7N
Plywood Carrier - http://amzn.to/2Dyej7N
Grizzly Track Saw - http://amzn.to/2Dyej7N
Bosch Sander - http://amzn.to/2Dyej7N
Sanding Pads - http://amzn.to/2Dyej7N
Drill - http://amzn.to/2Dyej7N
Drill Press - http://amzn.to/2Dyej7N
Flush Trim Saw - http://amzn.to/2Dyej7N
Sanding Block - http://amzn.to/2Dyej7N
Step 1: Turning One Sheet of Plywood Into a Bunch of Little Pieces
This project starts with one sheet of 3/4" 4x8' baltic birch plywood. You could use other types of furniture grade plywood, but baltic birch is the best of the readily available stuff
- Mark out a line in the middle of the sheet lengthwise, and then use a circular saw or track saw to cut the sheet in half. You'll have two 4' x 4' sheets minus the 1/8" kerf you just cut out. This isn't a big deal.
- Set the fence on your table saw to 5" and rip 4 strips from each half sheet. (8 total)
- Using two scrap pieces of plywood set your fence to the thickness of the two pieces. It will actually work out to slightly less than 1 1/2 inches. (3/4" plywood usually isn't exact. Especially baltic birch since they are using millimeters to measure)
- Rip 17 1 1/2 inch strips from each half sheet. (34 total)
- On the 5 inch wide strips measure them at 32". I set up a stop block to make repeatable cuts. Cut out 8 of these 5x32" panels. The offcuts from 4 of these 8 pieces will become the upper stretchers. Measure out the center of these 5 inch wide off cuts and set your table saw fence to match. Rip 4 these off cuts in half.
- Measure out 17" on the 1 1/2" strips. Set up a stop block and cut these down into 17 inch long strips. You need 66 of them total.
That last picture shows all the pieces for both chairs all arranged before the glue up. Speaking of glue up...
Step 2: The Glue Up
This is pretty straight forward.
- Glue up 2 sets of 21 1 1/2" x 17" inch strips to form the two seat bottoms. Having a flat glue up for the seat blanks will save you TONS of time sanding later. These Bessey clamps worked well for this.
- Glue up 12 pairs of 1 1/2" x 17" strips. These will become the front legs, and the 4 lower stretchers. I glued up all these 12 pairs (21 total strips) in the same clamps all together. I just skipped putting glue on every other piece.
- Glue up 4 pairs of the 2 1/2" x 17" strips that serve as the upper stretchers.
- Glue up 4 pairs of the 5 x 32" panels that serve as the back leg blanks.
Step 3: Making a Template & Cutting Out the Back Legs
The design of this chair centers around the 6 degree inward lean of the back legs. This is much easier to draw up than it sounds. I literally used a $2 plastic grade school protractor to mark out these angles.
- Referencing off the lower left corner of the template blank ling up the 90 degree mark with the left edge. Come in 6 degrees and mark a dot. Using one of the laminated 1 1/2" strips that is two pieces of plywood thick I marked the next start point. Draw a 90 degree line to reference off, and mark the same 6 degree angle. ( I used a 1/2" piece of MDF that I cut down to 5 x 32" to make the leg blanks)
- From these reference lines draw a 26 inch long line. Use the 1 1/2" piece to again make sure the leg thickness remains uniform and draw your second line.
- Next draw two reference 90 degree lines from the top of the 26" span. This gives you an easy surface to reference the 7 degree backward splay of the seat back. Mark out the 7 degree splay the same way you did for the 6 degree forward splay. See photos if that was confusing.
- Cut out your template. I used a jigsaw and took my time cutting this template accurately. I cleaned up the edges with a sanding block to get everything even.
- Transfer the shape of the template onto the 4 back leg blanks.
- Cut these out on the bandsaw, but be sure to cut outside of you lines. I tried to stay roughly 1/8" away from the line.
- Attach the template to the leg blank with double sided tape or hot glue.
- Using a 1 1/2" flush trim bit I flush trimmed the leg blanks to match the template.
Step 4: Cutting All the Pieces to Size
The cut list is in this sketch up file:
https://bit.ly/2HJFYaT (scroll down)
Seat: 16" x 14 3/4" x 1.5"
Side stretchers: 16" x 1.5" x 1.5"
Front legs: 15" x 1.5" x 1.5"
Front and back stretcher: 12" x 1.5" x 1.5"
Upper Stretchers: 12" x 2.5" x 1.5"
- For the seat use a cross cut sled to square up the sides and front. Set you table saw blade to 6 degrees and cut a bevel along the back of the seat making it 16" at its longest point. (The bottom)
- Cut the front legs to 15".
- Cut the side stretchers to 16 inches with the 6 degree bevel on the back end.
- Cut 7 degree bevels down the length of the upper stretchers on top and bottom. It'll look like parallelogram after.
- Cut the front, lower, and upper stretchers to 12" wide.
Step 5: Assembly
- Sand all the pieces up to 120 grit on the edge grain ply, and 220 grit on the veneer face.
- I used screws with dowel plugs to assemble the back legs to the seat and side stretchers. Everything else was attached with Festool Dominos. This is an expensive machine that costs a stupid amount of money. You do not need one to put this project together. Use screws and dowel plugs for everything. I will talk about my dominos since that is what I used.
- I made the drill guide pictured above, and this thing was very useful for marking out alignment lines as well. I used a 3/8" forstner bit and drill two holes centered.
- The top of the front legs get dominos centered. The seat bottom gets a matching domino. The side stretchers get a domino in the front that mates up with the front legs. The lower and upper stretchers get dominos on each end.
- Assemble the front legs and stretcher first. Assemble the back legs and stretchers. Once the glue is dry on both pieces join the seat to the back legs with the pre drilled screws. Attach the side stretchers the same way.
Step 6: Sanding & Finishing
- Plug the holes with dowels. I used 3/8" oak dowels.
- Do any finish sanding needed.
- Apply 3 coats of polycrylic or your favorite finish.
- Sit back (literally) and enjoy what you just made!
Thanks for looking!