Hello, and welcome to my how-to. I made this three layered wooden bowl from three pieces of wood that were glued together and carved on a lathe.
Step 1: Select Your Pieces
Technically, you can use any piece of wood for this, even just one solid one. However, I advise not to use a softwood, as it can scratch or dent very easily. I used three types of hardwood, ranging in color.
Step 2: Gluing the Pieces Together
After you've selected your pieces of wood, get some wood glue and four clamps.
Take one piece, and apply glue to each surface that will be in contact with the other pieces. Do the same with every other piece.
When you're ready, stick the pieces to each other. Make sure the grain of each piece is facing the same direction. Align them properly, then put your four clamps on the corners, and make sure they are tight.
Wiping off excess glue isn't necessary, as it will be turned on a lathe anyway.
Step 3: Cut the Corners
Draw as large a circle as large will fit on your block of wood. I recommend using a compass for this.
Once you've got your circle drawn, use a band saw to cut it. Don't cut right on the line, but rather cut just outside of it, maybe a 1/4"-1/2" away, depending on how steady your hand is.
Step 4: Turning the Block on a Lathe
Next, get your cylindrical block on a lathe.
At first, use a large chisel to round it out, and get rid of any large bumps or slopes.
Once it's been rounded out, start to form the shape of the bowl with some smaller tools. If your block is connected to the lathe with screws, be sure to not have them at the foot of the bowl, but rather where the hollow area would be.
Step 5: Carve Out the Bowl
Once the shape of your bowl is looking good, then it's time to carve out the hollow.
You know, 'cause it's a bowl.
Before you start to hollow it out, MAKE SURE there are no screws holding the bowl to the lathe. If there are screws that are hitting your tool, it will dull it and possibly ruin your project. Instead of screws, use a lathe chuck with correct jaws.
Anyway, use a bowl gouge to hollow the bowl out, keeping about 1/4"-1/2" inch wall thickness. There will be a nub that forms in the middle that the gouge won't be able to take out, so go ahead and use a normal chisel to take that out.
Step 6: Sanding & Finishing Up
Now that the bowl is all hollowed out, it's time to get some sand paper and get to work.
I would start out low grit, maybe 50-70, then 100, and if you want, 120. You don't need to go too high because when combined with the speed of the lathe, the sandpaper gives the wood a really smooth texture and a bit of shine.
The center of the bowl spins slower than the edges, so don't be afraid to do some hand sanding if necessary.
Once you're done with the sanding, get some mineral oil and give the bowl a few good layers, letting it soak in, and then you're finshed!