Sunday, 30 November 2014

14.10.14 Bronze pouring day

It is a bronze pouring day today, but this seems a movable feast. The last mould in the kiln finished flaming last night.  They had a problem with the VAT on some receipts – seems like the authorities make up the rules as they go along!

Email system seems to be quite good today – cut down on time writing several.  Able to send over the net but seem to be receiving the emails for Virgin automatically, but not able to access the gmail.

The clay l am using (river clay with quite a bit of sand in it) dries out very quickly and doesn’t seem to be brittle like the clay in UK – it seems to bake in the sun eg. the clay column l made as a maquette for the trees. Also the clay mounds l put under polythene with damp cloths still doesn’t keep the clay soft, it still seems to set and therefore only remain workable for a short time.

I will maybe do some clay negative plaques of sections of the ground with clay impresses today, to see what effect it gives and whether it would be useful to combine with something else, or whether they would be interesting in their own right.  We may be able to invest one or two of the trees today?? In between pouring.

Started the clay impress and cast the back with plaster – this goes off really quickly and feels quite sandy and rough, although luckily doesn’t have major lumps in it.  Cannot tell how hard it sets until l release it from the clay beneath – not much time to shake the plaster into the clay to prevent air bubbles, so don’t know how refined it will be.  Maybe try different mixes.

They have fired up the furnace and scrimmed the outside of the investments whilst still in the kiln, using sacking dipped in plaster.  Seven people are involved including Jacob, Emmanuel, David, Sanya, Muhuto, Adolf and one other.

It looked like lead was put into the crucible when it was nearing temperature.  Then the first pour was done – some concern about filling over the cup, which spilled over and therefore could have blocked the risers, but seemed OK.  Crucible was put back to reheat for 45 mins for the second mould.  They recognise the temperature by eye – if the iron rod, which is propped up against the opening to the furnace melts, it is too hot, and if it doesn’t glow, it is too cold.  Stirred in a lump of TIN (not lead) at the end this time, so it didn’t evaporate – needed especially for bell casting. Does this enable the bronze to pour more easily and fluidly?

The plaster relief l made was quite hard so didn’t need reinforcing.  Hopefully now the bells have been cast, there will be more time to get some research done.

Workshop tomorrow.  Emmanuel has brought in a watch, cufflinks Winnie bought him and his bible with the attributes of a wife needed – also above this a list under the heading of sex!!!

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