Missed this Gary ... 
I haven't looked at the link just yet, but reading what you say could be a valid point. I haven't yet started a new mix as i have been busy potting about, but i aim to do one later tonight.
My last castings are almost set, thou it has been about two weeks ... I will leave them in the tubes until they go solid.. The 2 cups are just about as solid as they are going to get, thou a little tacky on the top ... 