The first trial casting of the copper I smelted last year at the Scottish Sculpture Workshop was a success. I added a high percentage of silver (15%) and used the top temperature setting on my electric furnace and the copper alloy poured well. The first mould was a small toy person.
The Stone to Bowl project will use lost-beeswax, ceramic dip moulds and sling-casting, but I’m trialing different parts of the process using other technologies.
Following further research I have made up some clay balls with a mixture of malachite and charcoal inside to smelt. Copper results from removing oxygen from the copper ore, so the sealed clay balls should be more successful that the pit smelt that I did at the Sculpture Workshop.
I like the way the clay balls look a bit like poppy seed heads.
I’ll let them dry out a bit before I try and get them to smelting temperature in a charcoal furnace.
I have been awarded funding for my Stone to Bowl project. It will pay for several weeks at the Scottish Sculpture Workshop in 2018 to complete the project which will take copper ore through to cast pieces, using traditional and fully sustainable methods.
I’ve been doing some preparatory work:-
I experimented with melting the copper that I pit-smelted this year at the Sculpture Workshop, adding in some silver to lower the melting temperature. I melted 115gm and got 74gm of copper and some residual oxides which didn’t melt. The left hand metal is copper, the right is the original smelt material which is less pure. Next trial will be to sand cast with the copper/silver alloy.
This is a teaser photo of preparations for the iron pour that Steve and I ran at the weekend. It is the inside of a sand mould for an iron beaker vessel. I have put a piece of copper alloy from my beach combing into the mould to see what happens.
I now know what happened, but you will have to wait….
The pour was a great success thanks to George Beasley, Steve, Eden and the rest of the team at SSW. Thanks also to Charles Clark for the mould boxes.
The second ‘hole in the ground’ smelt produced copper in pellets, it was probably just a smidge too cool, but pellets will be super handy for casting.
We did a third smelt, but I don’t have photos as yet. It produced more consolidated copper at about the same ratio of ore to metal.
June 13 2017 with Eden Jolly at Scottish Sculpture Workshop