Plywood arm/lounge chair made out of birch plywood.

Step 1: Things You Need

Materials:

22mm birch plywood 40x120cm
2x 18mm birch plywood 20x120cm
Wood screws
Dowels
Wood glue
Danish oil

Tools:

I used the following tools, but you can substitute them with whatever you have on hand.

Track saw
Miter saw
Scroll saw
Hand drill
Orbital sander
Hand screw
Clamps
Ruler

Step 2: Design and Cut Material for the Frame

I sketched the design on the plywood until I was satisfied with it. Then I cut out the bottom side piece using my track saw and finished the corners with a scroll saw. You can also use jigsaw or bandsaw for this.

I repeated the same process for the back piece as well.

Step 3: Stretchers, Dados and Seat/back Supports

I cut the 18mm plywood into 6 slats - 3 for the backside and 3 for the seat. On the backside piece, I cut out dados with a scroll saw.

For the bottom, I cut a small strip of leftover plywood that spans between the front and back legs and cut dados out on the scroll saw as well. I then glued and screwed this strip to the side panel.

Step 4: Fill the Holes, Sand and Apply Finish

After driving a screw into each hole, I cut some dowels, applied wood glue to each hole to attach the plug, and then sanded them flush.

Finally, I sanded everything with 180 and 220 grit sandpaper. Since this is plywood, I was careful not to sand through the veneer, but I ensured that all surfaces were smooth before finishing with oil. In the end, I applied a coat of Danish oil and wiped away any excess.