UCL Primtech 2011 – running the metalworking sessions

At the very beginning of term the Institute of Archaeology, UCL, runs an experimental archaeology course colloquially referred to as ‘PrimTech’. It’s been running since 1982, when I am reliably informed Peter Drewitt was in charge, and takes all of the first year undergraduates away camping for a long weekend at a small scout camp at West Dean College.

This year was a bumper year of 82 students, which in addition to the Society of Archaeology (SAS) Students attending to run evening activities and cook, and all the staff and helpers, took the total number on site to between 120-130 people!

A few staff and demonstrators arrived early in the week, but the bulk of students arrived on two coaches Thursday morning to pitch tents. Food was cooked on site by the extremely able chef Robby Small, helped by SAS members, and sessions were split into half-days. Everything from basketry, to hut building, to flint knapping and spear-making occurred thanks to members of UCL staff and archaeologists and experimenters from across the country.

All of this was run with a very cool head and steady hand by Dr Bill Sillar, who I can only say has the patience of a saint.

This year, owing to my supervisor being rather tied up with his sabbatical and a beautiful new baby girl, I was in charge of running the ‘metal working’ activity. I have to admit this is one of the most fantastic experiences I have had this year. Anyone who has read this blog will know I love teaching , and absolutely love experimental archaeology, so PrimTech was a marriage made in heaven!

As there always is, we had a bit of a tentative start when bits of kit were found to be  a little wanting – out of something like six bag bellows on site, all but one had holes burnt into them! But after a quick trip back home I had the necessary equipment to enact some hasty – and not at all archaeologically accurate! – repairs and by Friday evening we were running very smoothly.

In all this I was extremely lucky to have the very experienced hand of Dr Oli Price helping out, and he built an absolutely fantastic and extremely beautiful furnace for the show-smelt on Friday night. Although we supplied the air to this lovely little furnace through the bag bellows, it was covered in holes which would originally have enable the furnace to be wind powered. As a result, every time we pumped the bellows flames roared out of the holes, which looked extremely impressive after dark!

By Saturday everything was going very smoothly, with the sessions running almost perfectly. For the first 30-45mins I sat down with the students and went through the very basics of metal production and casting, and we chatted about the processes and handled metals and ores and objects. Following this I had them mix up some clay with one of a variety of tempers – wood shavings working the best – and build their own little furnaces, which everyone seemed to really enjoy despite it being incredibly messy. At the same time there were chances to swap out and crush malachite ore (though I let them use a hammer rather than a stone!) and charcoal, and get the furnace lit.

Halfway through the session we took a half-hour break in the shade to rehydrate and reapply sunscreen, and then got onto the serious stuff – running the furnaces! This took the form of filling the furnace with charcoal and using the bellows to get it red-hot, before settling a modern graphite crucible in the centre and filling up the edges all around with more charcoal. To keep the fill of the crucible clean, we popped a second one upside down over the top as a lid. After that it was a good 20 minutes hard bellowing, and we were done! In each session we first we used a crucible filled with crushed ore and charcoal to smelt copper, then ran the furnace again with a new crucible filled with various metals – brass, copper, lead etc – and cast into sand moulds.

The casting didn’t go so well – in part because sand moulding is tricky, and in part because doing the pour alone is pretty difficult. Working with crucibles at over 1100C is very hard work – they are rather large objects kicking out terrific quantities of heat, which is intense even when wearing protective kit. Additionally you have to use large tongs to extract the crucible from the furnace and settle it in a sand pit, then swap to different crucibles to lift and pour – this is quite stressful and obviously any wrong move can be dangerous. In one case I couldn’t get the crucible to sit steady in the sand pit and it tipped over – though the sand absorbed all the metal (as it should) and I had cleared a big area so there was no chance of run-off.  This tipping was likely caused by the fact that we had managed to hit such high temperatures that we’d melted the outside of the crucibles and made the undersides rather irregular. As they have only a small base to begin with, this made sitting them safely in the sand rather tricky!

Despite this problem lots of students got to go home with lumps of metal they had made themselves, and they were all very positive about the sessions. A couple of times we failed to get the furnace to temperature, but this was largely down to the extreme weather – it was almost 30C during the day and we were working with a very hot furnace without any shade. Unsurprisingly not everyone could face bellowing hard in those conditions! I gave very thorough safety briefings at the beginning of each session, everyone had to wear suitable safety kit, and I was the one handling the crucibles, so I think the safety side was well covered. The one thing that was harder to deal with was the weather – some of the students didn’t tolerate the heat well and had to lie down in the shade for parts of the sessions despite the fact that I made sure we took regular breaks to hydrate. I assume past practitioners would have had similar issues, and that  it might be another contributing factor to the location of smelting sites adjacent to rivers.

The weekend was an absolutely fantastic experience, and I can only hope I will get the chance to run an activity at PrimTech 2012.Whilst the sessions were run primarily in order to give students an understanding of the processes which generate the archaeological material they will study, and the issues around spotting and interpreting these, I know that I learnt quite a lot and improved my own understanding of the processes. I had some absolutely fantastic students who were very engaged, very interested and really motivated. I hope that they had as much fun as I did, and that I get to work with people as great as them next time!