The Joy of Discovery

Jay Gaynor:We’re reconstructing an 18th-century cannon. We’re doing it just to see if it can be done, to be totally honest. So, there are several challenges. Trying to start out from scratch like we’re doing is going to entail some, hopefully some good reasoning and research and application. But there’s going to be a good dose of good luck there, too. Because we’re really trying to do something that has been lost for a long time.

August 20th is what we’re shooting for right now to do another test pour. We’re going to cast another coehorn, relatively small. We want to get that right, get our casting procedures down so that they work before we go for the bigger barrel. We start with a furnace, which was built by our historic trades masonry folks. The process itself starts out with preheating the furnace for a day or two to slowly bring it up to temperature to dry out the structure.

So once we get it up roughly to operating temperature, well, once we feel like it’s dry, we’ll put the bronze in the furnace. There’s an access door to do that. Then we’ll slowly bring it up to the melting point of the bronze itself. And at that point, the bronze itself melts. It’s in a liquid form in the bottom of this reverberatory chamber.

Once it’s at that point, we actually have a long iron rod that’s got sort of a point and a bulb on the end of it, and we use that to push out an iron cork that’s in the side of this melting chamber. Because it’s got that bulge in it, you can shove that in and it acts as a valve for the pouring-hole itself. So you can slowly then ease it back out in the other direction and that allows you to control the velocity of the bronze coming out of the furnace.

It goes down a relatively short trough, maybe 18 inches, and runs from there literally into the mouth of the mold itself. The pour takes literally a matter of seconds, less than a minute to get the bronze in there. Then we’ve got to wait overnight until it cools down to the point where we can dig it out and see what we’ve got.

We start knocking the mold off of it, and it’s brittle enough at this point that you can take a hammer and start breaking it off. That’s when we see what the surface of the casting looks like.

The blog is up on the Colonial Williamsburg internet site, it’s called “The Cannon Blog.” We’ve been able to post a lot of photographs there of the cannon up to this point. But what’s been neat about it is that we’ve attracted a huge amount of input from folks that have been interested in this topic for a long time. We’re getting some really wonderful input from folks that is helping us a lot to think about what we’re doing and refine the whole process.

But I think it’s just exciting to do this stuff. It’s detective work, it’s hands-on, and it’s something that Historic Trades is really all about. We’re having fun, and when we get to the point where we feel like we’ve got it down and we’re going to have a successful big-barrel pour, we’ll let everybody know.

© 2012 The Colonial Williamsburg Foundation