The allure of copper – Stone to Bowl

Alongside the traditional copper casting project I have done a copper/silver cast; using plumber’s copper and silver.

and two-part sand moulds. This is partly sustainable, with all materials being recycled; but the heat used is gas.

One of the pieces sold unfinished at ENOS 2018. The bowl has a metal ‘pebble’ inset, a blue heat patina and is almost clean copper on the exterior because I used a different greensand on the outside.

Some learning – try different sands to give cleaner surfaces but retain textures, cost in the silver, keep experimenting, copper is an attractive metal although challenging to work with.

Stone to bowl – finger tips

A bit of a leap forward in time. These are the first pieces cast in copper from beeswax lost-wax models dipped in clay mix. I’ll explain the process more later.

The finger tips are a simple development of the work that I was doing in Munich and were a good test of the process, being very fine but also small. I like that they are handmade by me for my hands; and exemplify the whole process- having been made using environmentally-friendly, traditional processes.

The surface finish is pitted, but I like this and I plan to make more. It would be fun to do a community finger project.

Takako Selway and I will do some filming of the process for her film about “Hands Making”

Stone to Bowl. Copper smelting

Finally I am three weeks into my Stone to Bowl residency and I feel that I should share progress.

One element of Stone to Bowl is to develop a replicable way of smelting copper from malachite/copper ore in a traditional way that means that I can work in the landscape anywhere.

First task was to source some Scottish copper ore. The mine in Bridge of Allan is long closed, but I found some copper traces on the waste heap. These photos show the mine entrance and the pieces that I collected.

After initial smelting experiments I have been putting the ore in closed ceramic  balls with added charcoal to give a reducing atmosphere for the smelt. (While I was on my residency another artist was successfully smelting malachite using oxy-acetylene.)

The furnace is charcoal burning; and for these experiments I was using an electric air blower, although I will use bellows when I understand the process more. The dry ceramic balls are made of a local refractory clay mixed with fibre -horse dung, and sand. Inside is copper ore in pea size chunks  with 25% charcoal. The balls are placed on the furnace charcoal once it is burning well and the furnace is run until the ore is to a high enough temperature to smelt, hopefully. The balls are then plunged into water and broken open.

The first smelt was not a complete success. Some copper was formed, but a lot of this was pelletised rather than consolidated and some had to be panned from the ashes of the furnace.

However I reheated this copper to consolidate it and a reasonable amount of copper was retrieved. Again I used an electric furnace for this process while I am experimenting.

I am not sure that a chimney furnace is needed, a horseshoe hearth might be as successful as one can see what is going on. The chimney furnace is made of a refractory clay mix similar to that used for the balls.

I tried another smelt later in the residency of which more anon.