chris collister Jan 8, 2013:

What kind of plaster? Lime plaster is sadly almost unknown in GB, but essentially "plaster" is either hydrated calcium sulphate (gypsum) or calcium carbonate, where it arrives by reacting with CO2 in the atmosphere via calcium hydroxide (hydrated lime) via quicklime (calcium oxide) via initial heating of calcium carbonate (chalk). The correct term (though I confess to liking "cooked to death") would depend on what type of plaster is involved, though I can't help feeling that the physical properties are simply a function of how pure the initial material is. In the case of gypsum, less water of hydration would lead to a longer time of reaction: old plaster of paris (which has absorbed water over time) tends to go off within minutes.

Tony M Jan 7, 2013:

The quick and the dead I don't know if it's any help, but I know that highly reactive lime is 'quicklime' ('quick' with the old sense of 'living'), so I suspect what you have here is by extension 'deadlime' (cf. nautical use of quickwork / deadwork).