November 14, 2012
Setting the mold in the pit.
It looks like we have a barrel! With many of the same folks at the furnace as this past May, we made a pour on Thursday, October 25. The experiments, records, and insights that came out of the spring attempt had been applied methodically as Jason and his team repaired the furnace, the blacksmiths provided additional iron banding to help control the furnace’s expansion and contraction, and Stephen Williams from Newport News Shipbuilding worked with Jason to line the melting chamber with a refractory material that repaired the cracks and ensured a more reliable container for the metal as it melted. In the meantime, Mike and Suzie completed another mold, and they and George arranged to have it fired at The College of William and Mary’s pottery studio.
Heating the furnace.
We began heating the furnace on Monday evening and gradually increased the fire over the next two days. When it was time to ramp up the temperature for the melt and pour, Phillip Harrison was ready with his data from last time. Working with apprentices Shanae Hilliard and Kevin Williams from Newport News Shipbuilding, Colonial Williamsburg Historic Trades folks from a number of shops as well as the gunsmith and foundry, Jane Rees, and Billy and Nancy Stark,our ever-faithful supporters and volunteers, he coaxed the furnace to the desired temperature like a musician playing a fine instrument. While that was going on, another crew set the mold in place, assembled it, sealed it, and backfilled the casting pit.
Skimming the bronze.
We were aiming for a 3:00 p.m. pour, got to the desired 1850⁰F about four or five minutes after that, and then waited a few minutes to ensure that we were holding the temperature. That turned out to be the case, so George, Mike, and Stephen poled the molten metal to make certain there were no solid lumps, skimmed off the slag a couple times, and ensured all was set to go.
The bronze is poured.
Stephen put the last ingredient into the furnace, a small amount of phosphorous copper to deoxidize the molten metal and increase the fluidity. Mike and George pounded in the tap hole plug. Bronze flowed beautifully out into the mold. There was a short pause at one point when Stephen had to clear the hole from the furnace-door side, and then the rest of the metal was on its way. When the furnace emptied, the mold was filled to within six or eight inches of the top of the deadhead. It all looked good, but nothing more could be determined until the next morning. After a bit of tidying up, there were a few hours for decompression and celebration before a pretty exhausted bunch headed home for a good night’s sleep.
The next morning, Friday the 26th, members of the crew as well as a handful of onlookers gathered at the furnace. They excavated the mold, hoisted it from the pit, and went at it with a sledgehammer to begin breaking the mold material away from the casting. Gradually the deadhead and the barrel itself began to emerge. Within half an hour, there were trunnions, a cascabel, a nicely shaped muzzle, and everything in between. With a great collective sigh of satisfaction, the experts pronounced that it looked good and sounded good, ringing like a bell.
The proof will come when we start to clean up the outside and drill the bore—but so far, so good. It was a great crew. The efforts of many, and the coordination of it all was, once more, a joy to watch. More to come, but for now, a big thanks to all!