THE CRAFT OF FIRE

Last time we melted and cast bronze , we figured we had to build a new furnace since, after ten firings, ours had a serious crack in it. But then we thought, instead of doing all that work, maybe we could get away with wrapping ceramic fibre around the furnace. Here's how it went. We loaded up our crucible and set it into the furnace after the charcoal was burning well. And then we piled on the charcoal to completely cover the crucible, and waited.   When we first melted bronze and brass , we didn't need any external air source; the natural draught provided by the three entrances along the bottom of the furnace were sufficient. But since then we haven't been able to melt bronze without adding forced air from bellows. Perhaps we haven't been loading the furnace with charcoal correctly, and the entrances at the bottom are getting blocked by small bits of charcoal. Perhaps it's time to re-read the original paper that guided our building of this furnace. However it is,...

There's a cemetery near my house where I regularly walk my dog, and in it there's a Norway spruce tree that produces a lot of resin.  Over time, I've collected it, thinking that it could serve when we make casting wax. Here's a nice, clear piece: Our recipe for casting wax is 70% beeswax, 20% paraffin, and 10% resin. In the past we've used store-bought gum arabic or damar but this time, we decided to use this cemetery pine resin. (We tried using a resinous substance from a Kentucky Coffee Tree  once, but it didn't work.) First, we needed to get the resin ready, cleaned up as much as possible, purified of bits of bark, insects, and the like. I heated it up with a double boiler, assuming it was safest to use gentle, indirect heat on it.  It didn't take too long before it started to melt. There were some chunks, though, that took much longer to dissolve than others, even when I put the pot directly on the heat.  In the end, even when everything was boiling away...

The weather is better so we're back at it with the bronze furnace. I think this is our fourth attempt at casting bronze into our plaster molds. But our poor furnace is on its last legs - that crack goes almost all the way around. Will it survive another firing?  We gathered up pieces of our bronze, almost a kilo's worth, and put the crucible in about halfway. Then we loaded up the furnace with more charcoal. Our crew was joined this time by our friend Gina who has been wanting to join us for a long time now - most of these photos are hers. So nice to expand the team! We had a few molds from previous sessions that had never been filled: a pinecone, salamander, a yonilinga, the usual... The furnace got very hot very quickly, and after about 1.5 hours we figured we might be ready.  But once again we were left puzzled by the workings of this most primitive of bronze furnaces. On previous occasions, two hours was more than enough time to melt bronze. This time, we discovered that, ...

I can't believe it's been so long! Not sure what happened; I thought I had posted about our second round of bronze-making, but I missed it. And the subsequent casting session, too. So, here goes: In June 2024, we made bronze again. We had made it successfully for the first time in May , so this was really just about making more, and getting more familiar with how the furnace and bellows worked.    It was all pretty straightforward, and the furnace worked like a charm. It took less than two hours from set up to pouring.  In the video, you can hear a big "crack!" near the end - we all got spooked! But it was just the concrete under the muffin tin that couldn't take the heat. See here: We got ourselves two good muffin ingots. And while the amount of metal that went in didn't quite match what came out, I'm guessing we lost some through dross or spillage here and there.   In September, we tried to cast our homemade bronze into these plaster moulds: But for some...