Lots of air flow for oven. Top temp hold 3 hrs. vacuum or vent or both. I cast the smaller pcs with no venting. Complete curing maybe part of the problem some are having, just haven't cast enough to really know. out of the four pieces cast, no failures. Will try casting some more in the future . Extremely busy with orders, not a time to be testing.
Have no experience with thick walled items, yet.
Dance like nobody's watching!