woodturning a small square sycamore bowl

I made a square bowl out of a piece of sycamore wood. First, I mounted the wood on the lathe using a faceplate and, in this way, turned the outside, sanded it, and applied two coats of sealer. Once the sealer had cured, I attached a plywood tenon to the bottom with melt glue and mounted the bowl reversed with the plywood tenon in the chuck, then removed the faceplate. Next, I hollowed out the bowl, sanded it, and applied two coats of sealer. Once the sealer had cured, I sanded the bowl to 600 grit and finished it with friction polish I then removed the bowl from the chuck, softened the hot melt glue with denatured alcohol, removed the tenon, and finished the bottom of the bowl just like the rest of it. The bowl is 15 centimeters square and 5 centimeters high.