71 BURNING OYSTER SHELLS

EXACTING WORK REBUILDING THE CHIMNEYS EXTENDED TO CREATING A LIME MORTAR.

In his drive to be as authentic as possible during restoration, Brian Cooper built a kiln, or lime rick, using eight cords of dry oak and two cords of green oak to burn oyster shells—re-creating the process used by early coastal builders to make quicklime. “We got the information about how to do it from Colonial Williamsburg,” Cooper says.

With the help of Hill Town Restorations, a traditional Jamaican oyster lime kiln burn was constructed and burned to produce a historically accurate, beautiful white-lime putty. It took 30 hours of intense heat to drive the carbon dioxide out of the oyster shells. The shells, 40% lighter, were placed in vats and warm water was added. Within 45 minutes an exothermic reaction began and the water began to boil. Water was then added to the resulting calcium oxide to slake the lime. The soft mortar made from the slurry is especially good for use with soft, pre-industrial brick.

“It’s a slow, laborious process, dependent on the availability of a lot of oyster shells,” Cooper says. “As soon as they discovered dolomite, or limestone, they stopped burning oyster shells.”

RIGHT The burned shells are put in water, where an exothermic reaction breaks down the shells to create slaked lime, a soft putty, which is screened into a pit.

The lime kiln or lime rick is a 16’-diameter circle of stacked wood, surrounding 3500 lbs. of oyster shells; it will burn at 1800°.