I picked up quite a bit of structural plywood (laminated timber) from a skip bin (dumpster). Instead of going to landfill, I decided to recycle it.
Step 1: The Wood
The dumped structural plywood is mainly off-cuts. I suspect it was used for making staircases, which is why there many triangles and other odd shapes. For this project I used one of the smaller pieces.
'Being structural plywood it's solid and has very few 'holes' you sometimes get in cheaper wood.
Step 2: Preparing the Wood for the Lathe
I marked a circle with a compass, and cut it with a drop saw close to the line to reduce the time spent at the lathe. A band saw may be better, but I don't have one.
Step 3: Truing and Making a Tenon
I mounted the plywood between centers on the lathe. Using a bowl gouge and a parting tool I smoothed the outside to circle, and created a tenon for mounting the blank in the chuck.
Step 4: Shaping
The bowl is chucked using the tenon. I shaped the outside and hollowed the bowl using a bowl gouge and a scraper.
Step 5: Sanding
Still mounted, I used sandpaper (gradual from 120 to 400 grit) to sand the inside and outside
Step 6: Shaping the Bottom
I reverse chucked the bowl using a jam chuck (made out of plywood of course) and using a parting tool I cleaned the bottom. The very last bit needs to sanded. The bottom is shaped with a ring on the outside and the inside is recessed a bit to ensure stability.
Step 7: Finishing
I used my own wood butter (bees wax and tung oil) to finish the bowl.
Step 8: Done
The bowl I made today is on the right, with another bowl I prepared earlier.