MB Finearts Bronze Foundry Work ExperiencePosted: September 1, 2014
Over the months of July and August I spent a total of 3 works working at M.B. Finearts Foundry with its’s owner Mr Martin Bellwood. The work done there varies from sculpture to signs to other non metal casting work. I mostly worked on sculpture.
During my first week I was introduced to a large variety of processes and techniques in most areas of the foundry (excluding the wax room). The first day I spent making silica sand moulds, these were larger than any I had made before and these particular ones were thinner than I was used to making also. The first things I cast were 2 pieces of driftwood to be used as base plates for two Helen Sinclair sculptures. Martin is a good teacher; he’s clear, patient and happy to answer questions of which I had a many. The foundry staff were all friendly and interesting people from seemingly all walks of life, I got on well with them and felt I could ask them for help should I need it. The sand moulds were made in large metal frames which had cross pieces that supported the sand.
The mould is sealed with a graphite/paraffin solution, this is ignited, after it has burnt out it leaves a thin protective layer over the delicate sand mould casting surface and also makes less likely for the sand to stick to the pieces.
These moulds are then clamped together to stop them expanding whilst pouring, if the moulds were really big and heavy they may not have needed this. This helps ensure a clean cast with no flash and no step to the cast where the mould lines are.
Once the metal has cooled the sand mould is broken away with a hammer to reveal the work.
The work is now either sand blasted or pressure hosed to remove as much casting material as possible quickly, a blasting cabinet or hand tools are then used to remove trickier bits. The work is then cut off the runners and risers and re-detailed and polished.
Some other things I worked on:
On my second day I spent the first half of the morning cutting up a large old vandalised bronze sculpture with a big angle grinder, it was hard sweaty work and I was soon covered in bronze glitter dust. After that I helped to prepare the workshop for the bronze pour by tiding away arranging tools and making ready supporting sand buckets for casting trees. The trees come out of the bottom loader kiln and are placed in the sand buckets with sand poured in around them to support them during the pour and keep them upright. The flames rushed out of the kiln top about 8ft as the wax melted and the ceramic walls fired. After lunch the bronze trees (crucifixes) were poured, this was all very exciting with lots of smoke, flames, noise and a great fierce relentless heat. Excess metal in the crucible is poured into ingot moulds were I could see the separation of the copper, zinc and tin with zinc burning off the top all bright yellowish green. Zinc fumes are very bad! They make you feel faint, give you headaches and cause your limbs to shake uncontrollably (bit like short burst of severe flu).
On my third day I learnt to use a large variety of tools in different ways for example; how to use files in different ways to achieve different marks, different ways to use angle grinders (got quite good at getting the cutting wheel close to the work so less grinding was needed), I also used a range of compressor powered air tools for grinding and sanding and shaping and detailing. With large dremel like tools I cleaned up mould lines and flash and resculpted lost detail caused by the runners and risers. I learnt to use a tap and die tools to thread my own bolts and holes for sculpture mounting points – when threading a bolt the starting end must be tapered to allow the tap to cut into the material, once it gets going make complete turns and then reverse half a turn to remove the burr thus allowing you to continue threading.
On my last day I spent the morning preparing the crucifixes for the local church for engraving and staining. That afternoon was a bit quieter, Martin showed me his experiments at using 3D printing in bronze casting to do direct pour out moulds using PLA. We did some scanning experimentation with 2 of his many scanners. One was a very expensive hand held scanner that had its own software, the other an Xbox Kinect. We found the Kinect easier to use although the detail was nowhere near as good. We used the stl. file we had just created to print of a 7cm or so high bust of my head and shoulders in black PLA.
After my week of work experience several weeks later I had an email from the foundry offering me more work which I was excited to take, and so I worked for two more weeks gaining loads more experience before heading off to uni. I hope to go and work for the foundry again in the future and to continue my growing relationship and experience with bronze casting.