In August all was ready for the casting of the iron units and off I eagerly trotted on the train up to Hargreaves Foundry in Halifax to be present during a famous ‘Casting Thursday’! – I have been up to Hargreaves only once before and Andrew Knight, Foundry & Patternshop Manager showed me around the factory at that time. Even though this was impressive, (& it is !) it couldn’t match being present to witness my own work being cast. It is such a physical, visceral process, fully hands on and dangerous with it. The skill & craft is astonishing and it is this legacy of making, which Hargreaves has in bucketfuls, that I wanted to design into the public art work for Rochester.
Nine cast iron units have now been made, from 5 original cnc tooled patterns manufactured to my designs by Arthur Jackson & Co Ltd, Halifax. These patterns, cnc tooled from a type of resin block are used to prepare the resin sand mould boxes used in the final casting process. The cast units are then hand finished through grinding and polishing methods.
Individual one ton iron weights are used to secure the moulds during casting, such are the pressures of heat during the process. The moulds are constructed from a resin infused black sand, which has been compacted around the master pattern, which is then removed.
What I can’t convey here is the noise, heat, smell & excitement of this process during the critical stages of casting. The experience is vivid and visceral. I am watching something being made which could last for hundreds of years.
The units above and below have now been treated with Nitric Acid to prevent rusting through oxidation. The cast iron is almost black and the relief jumps out very cleanly.