Excellent news to report. We went to our kiln this morning and attempted to slake some of the shells on site.There were essentially two types of material in the kiln this morning. The well burned portion of shells that were to the rear of the kiln had broken down into a white powder. The lesser burned portion still had their shell shape and were dark grey but easily broken. We added water to samples of both on site and nothing visible happened. Not surprising. We had a very heavy rain on Sunday and although the kiln was tarped I expected that the high RH might have impacted the shells. We scooped up several pints of material and took it back to the lab for further observation. When we arrived in the lab I could tell that the bottom of one of our containers containing the burned shell was getting very hot. We quickly ground and sifted the fine material and put it into a large beaker and added water. Nothing happened at first but after about 15 minutes the beaker was very hot to the touch and it was clear that we had achieved the creation of quicklime from the oyster shells burned in our kiln. The resulting slaked material was extremely fine and pure white. I poured the mixture into a plaster mold we had in the lab to see how the material would set overnight. Not bad for a bunch of dumb college boys who had never even built a kiln before last week. Thanks to all BPers for your helpful suggestions and encouragement. Next step, perfecting the kiln process and continuing with rick burning experimentation. I'll keep you posted as to progress. Brian Brian Scott Robinson, MHP Professor Savannah College of Art and Design School of Building Arts Historic Preservation Department P.O. Box 3146 Savannah, GA 31402 912 525 6940 office (Tues/Thurs) 912 262 2650 home (students emergency only) >[log in to unmask] <BR><BR> <BR> -- To terminate puerile preservation prattling among pals and the uncoffee-ed, or to change your settings, go to: <http://listserv.icors.org/archives/bullamanka-pinheads.html>