I've been processing clay with a drill mixer in 5 gallon buckets in order to plaster the interior of our SB home in Northern Michigan. When I add 1/2 cup of lime putty to clay the consistancy of thick slip and mix for about ten seconds, it thickens enough to stand up the drill. It becomes much stiffer and more plastic. I'm not sure what this means but I keep adding lime to my plaster. Keith