Successful test
On Wednesday afternoon, we dug out the sand and dirt around the mold, raised it out of the casting pit with block and tackle, and set the mold on the ground.
The founders removed the iron bands and straps reinforcing it and cracked the ceramic mold away from the casting. What lay inside is, to all appearances, a still-very-warm, but beautiful casting with excellent surface and detail.
We won't know for sure about its soundness until the deadhead is sawn off, the surface skimmed, and the bore drilled, but so far, looks like SUCCESS!
A second coehorn model is in the works for the Metalworking for Revolution conference starting this weekend. Not sure when we will attempt another casting. A lot depends upon a detailed inspection of the furnace and a determination of what, if any, repair work is required before the next melt. Stay tuned!
It's when you do things like this that make me wish I lived closer than Northern Indiana so I could drop in and watch. The blog really helps let people know about all the work that goes on during the year.
Will the coehorn be tested by firing it? Why was this type of mortar chosen for the test pour? Would it have been used in the 18th century?
Congratulations Mike, Roger, and Suzie!
I'll try to drop by during the Thanksgiving break to have a look!
The mold is indeed loam. After the process of heating to “neal” it, it resembles low-fired earthenware, but calling it “ceramic” at that point probably is stretching the term.
Ceramic is made from clay or another non-metallic material fired at a high temperature. Clay is a component of loam. Therefore, you are in part correct. The mold is loam, but since it was fired during the casting process, it was turned into ceramic.
Wow! This blog is really cool! I never knew what all went in to making a cannon. Although there is still more to learn in the next entries, I have already learned a lot. I am so glad you started it so we could watch the progress. Another plus for Colonial Williamsburg...which has not even one minus!
I thought the mold was loam not ceramic??
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