Sunday, August 8, 2010
Kate had a bunch of copper wire clippings spare, so I tried melting them in the furnace. Using a sawn-off steel CO2 container with its bottom flattened as a crucible and the sawn-off bit poked into the top to reduce oxidation. I also added a bit of glass to float any slag.
As you can see, I managed to get it up to a fair old temperature, glowing yellow hot and some. The copper melted inside the container with an amazing amount of outgassing.
So the picture makes it look like gold, but it was copper. Not that there's much of a difference in melting point. The big surprise is that it came out as bead-like globules. Hopefully a clean re-melt will fix it.
This melt was done with homemade charcoal, which produced an excellent heat. Next I'll be using smaller chunks, and mould a sloping trench to direct the charcoal into the path of the incoming air blast. Out into the rain we go to mould the clay while it's damp...