Iron Age bronze working

We had such fun at the final public event for the Clachtoll Broch project.

Uist Corrigan (who is now at Edinburgh College of Art) joined me and some local folk and volunteer archaeologists. (That’s Uist keeping an eye on the furnace)

We had the bellows from SSW and built the furnace using local clay, sand and horse dung.

We had some local charcoal courtesy of Chris (although most of it came from the Chinese wholesalers in Dundee). Heather Fulton took loads of photos, some of which I’m using here.

We started before dusk and did the final copper smelt of the project.

Just about everyone helped with the bellows, it’s not so easy, but it’s sociable, thanks all who joined in.

We cast the two community bronzes which were lost wax cast.

This is burning out the wax.

Pouring the bronze and, below checking out the crucible for the next pour.

One of the bronzes was a bear foot print, designed by Bill.

I had spent the previous week preparing the waxes, adding runners and risers and then  dipping them in a clay slurry mix to build up layers of mould which was then finished by enclosing in a cob clay with a pouring funnel.

We kept the furnace going (and the bellow workers) to pour the last bronzes – One closed oil sand 2-part mould, an open sand box with local sand and clay mix; and a closed 2-part mould (although we ran out of bronze in the end)

Most people went up to hear Gordon’s talk, but I’d promised Mandy Haggith that we’d try a copper alloy. So we switched to the hand blower to melt the copper, including from the local smelting, and added some tin grain to get a very local bronze alloy.

The open sand mould was Roz’s bird over waves design; and the closed one Stuart’s panda:-

The next morning I said goodbye to the Art Studio for 2018 and headed back to my studio to finish the final bronzes.

My thanks to everyone for making the Clachtoll broch art project such good fun.

Clachtoll Art Project – Bronze community sculpture

The other piece that I’ve been working on is a community sculpture.

Eighteen children from Lochinver primary have prepared designs and tried their hand at wax carving using local beeswax.

Most of the children also did sand piece-moulds to cast metals beads which we then made up into nettle-stringed necklaces. Thank-you to the people who supported me with this workshop.

I then cleaned up the waxes so that they would cast well; and using the same method as the children (2 part sand moulds), I cast the first sixteen mini sculptures in bronze. I have been cleaning these – cutting of the running system, filing them back, sanding and polishing them.

The Ullapool High school children who came to the broch helped run a copper smelt. The copper from that smelt was added to the bronze used for these mini sculptures. The high school pupils also cast pewter pieces using clay models that they had designed themselves.

The community sculpture has been growing with local people making mini sculptures.

At a public event on Stoer field we smelted some more copper, which will be used in casting these waxes in bronze (thanks, Nigel, Fiona and Boyd)

Many of the dig volunteers and other people involved with the broch have added their designs, so I have a further 24 waxes cleaned and prepared for casting.

The discussion on where they may be installed continues, but I hope they can be affixed to bedrock in a safe place near the broch.

The final public event at Glen Canisp on 16^th November 2018 will be to cast the final waxes for the sculpture (including copper from the public smelt). We also have a special request to demonstrate the alloying of copper with tin to give bronze. I hope to have more details of the event planning soon.

 

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.

Casting on the beach

Using Holger Lonze’s practical research into Bronze Age techniques I made a lost beeswax clay dip mould which I cast in recycled bronze on the beach at Cellardyke..

This is me working the bellows. I shared this task with Roddy Mathieson and Gordon Lochead.

This is one of the charcoal fueled furnaces

Me pouring the mould.

breaking the mould to get the cast out.

Cleaning up the cast bronze vessel.

The piece ready to have the runners and risers removed.

The final piece is part of my degree show – so may be seen on May 22 in Dundee