Showing posts with label melt. Show all posts
Showing posts with label melt. Show all posts

Sunday, August 8, 2010

We Melted Gold(ish)!


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...

Saturday, July 31, 2010

Can Melting Update


Using the bottom of a MAPP gas can, which is larger and sturdier than a coconut cream tin, I've managed to melt and cast 20 cans at a go - and I still have a lot of my $6 bag of BBQ charcoal left.

When you get enough in the can, the aluminium squeezes out of the dross easier and you can pour it directly into a mould.