Here is a picture of the boxelder form I helped one of my High School students save from a large very rotten boxelder burl he brought in. It was like turning cardboard. We had to soak it 3 or 4 times with deft to ever get a finial cut. I had to help him a lot with the hollowing. With out the ad of a captive hollowing system it was a little deep for him. It is 11" tall by around 8 1/2" in dia. It has more coats of deft on it than he can remember he say's. It is where I got the form from for my last bowl I posted.
Jack