Stone to Bowl grand finale

Last week was my final week of work at Scottish Sculpture Workshop on my VACMA funded Stone to Bowl copper project.

It focused on getting the bellows organised so that I can work anywhere in the landscape. Monday was spent fixing the blower which had arrived fractured. Eden Jolly did most of the work as it involved tig welding, but I did the cleaning of the joins and offered cups of tea. Eden and Fleur (an Erasmus student) made it a super wee base and I went to Portsoy to get it some flexible tubing. fanblowerSept18By Wednesday all was ready to return to copper smelting trials. The smelt balls tend to over heat in the shaft furnace as it’s hard to see what is going on.

smeltfurnaceSept18

So on Thursday I dug a pit furnace and trialed that smelting with great success.I got 35gm copper from 50gm ore in 30 minutes and using about 2kg of charcoal.

smeltballSept185i

On Friday it was time to trial the bowls mentioned in the project title. This was using ore I’d smelted alloyed with 10% silver. The photo shows the open mould after casting. The copper did not complete the pour. I need to redesign the bowls with a thicker base. Even after heating the moulds and with sling casting, the copper would not stay molten in such a thin walled vessel.

slingSept18i

Spending 4 weeks developing processes and tools has been brilliant and the work goes on.

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Packing list NEOS 2

coppersplash

I’m trying out this copper/silver alloy bowl on a patinated mokume gane disc. I’ve tried other stands, but the bowl ‘stands’ well on its own, so I’m going for something simple that highlights the blue patina.

charmsneos

There will be some of my charm jewellery going to Art in the Buchat, Glenbuchat as well. I gave it a little polish and its tucked up in its boxes now waiting to charm visitors from Friday, 7th September.

 

Stone to Bowl

bloweri

Finally the hand cranked forge blower has arrived. This is hopefully the last piece of the Stone to Bowl project. The forge blower will deliver air to the furnace, powered by hand rather than electricity. I’ll find out next month at SSW if it can be made to work. If the bellows can be hand powered it means that I can work anywhere,

day7smeltblower

This is the model we hope to replicate.

Stone to Bowl clay dip moulds; incl wax melt out and all-in casting

Returning to Stone to Bowl:-

stonetobowlmouldfiringOnce the wax models have been made and sprued they are then dipped in a slurry mix of clay (this time from Kingsbarns) sand (Cellardyke beach) and fibre (horse poo from near Kilrenny). There are two mixes, one is fine and the early coats are done in this and the other is coarser to build up the outer layers. Each layer has to dry before the next layer is added so it takes several days to build up the mould.

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When the mould is built up a clay funnel is added. The moulds are then ready for the wax to be burnt out. The first photo shows the burn out. Below are the moulds that have been burnt out.

stonetobowlburnoutmoulds

The link below is to an animated film about lost wax casting, which explains the process well.

https://hyperallergic.com/286780/an-animated-guide-to-the-bronze-age-technique-of-lost-wax-casting/

I also tried out a casting method where you burn out the wax and then put the copper alloy in one end of the mould. You then seal up the mould with a lid and clay mixture and return the mould to the furnace. stonetobowlmoulds

This photo shows the moulds and lids ready for burn out.

stonetobowlallinmoulds

This photo shows the all in one moulds ready to return to the furnace for the copper melting stage.

In theory the copper heats to melting point and you upend the mould and the copper pours into the part that you want to cast, In practice because you can’t see the metal it is difficult not to either get incomplete melting or over heating and the metal seeping out through the ceramic shell.

stone2inmouldcasting

The photo shows incomplete melting, the copper is fused (bottom right)

stone2allincast

This photo shows a mould where the metal over heated and seeped through the mould walls. There are two moulds, one complete (but rattles so I’ve not broken it) and an open one.

The moulds with incomplete melting can be ‘re-used’ as open moulds.

 

Stone to Bowl model making

waxfingersprued I make my models using beeswax from a beekeeper who lives near St Andrews. She and her bees make lovely wax that smells delicious and is just right for making models.

I  started small but wanted to make fine models to challenge the techniques. I made finger tip rings by dipping my fingers in the melted wax. stonetobowlJuliaCowieThese then need to have pouring stalks added (sprues). They are then ready to be dipped in the clay mix to build up the mould.

stonetobowlday11iv

After successfully casting finger tip rings I moved on to small bowls which were made by dipping clay bowls in wax and adding pouring stalks.

 

The allure of copper – Stone to Bowl

copperbowl2018

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

copperpourjuneiicopperpourJunei

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

copperpourJune

copperbowl2018i

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

fingersiii

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.

fingersiv

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”