David how long did you let your turnings dry before finishing? I generally let them sit in a bag for about 3-5 days and then sand by hand and finish. I find cracking usually occurs when I have left any areas too thick and depending on the species. I have the Trent Bosch hollowing system only thing I am finding is it would be nice to have a cutter like Lyle Jamesons adjustable hollowing tool that is bent sells for $70.00 American. I have been trying to get as small a hole as possible on the top of my hollow forms. Here is my first try, the one on the left approx. 6" square, .75 inch hole. The one to the right is 1.5 inch hole approx 11" in height. Just finished them last week.