Casting a Bronze-age Sword
This is what we did at the weekend! It was hard work but immensely satisfying. We traveled to the Bronze-Age Foundry in Wales, run by the amazingly talented David Chapman, sculptor, artists and bronze worker.
We used recycled copper from electric cables, which is very pure, and tin to make a 10% tin bronze mix. The copper is first heated over the flame to drive off water, as a steam burst can make the crucible erupt molten copper. Here’s the tin being added to the copper.
Here’s a bad picture of the copper being poured into a soapstone mould. Soapstone is excellent for casting, as it absorbs, stores and radiates heat evenly.
After a few minutes cooling the sword came out of the mould. Here is a stack of previously casted swords. Note the triangular sprue on the end of the hilt – first job is to cut that off with a hacksaw.
The sword we were making is a copy of one in the Pitt Rivers museum in Oxford, dated roughly between 1000-800 BCE, and found in the Thames near Limehouse
And the second job is to snip off the spare bronze along the blade edges. Like the sprue lumps all these little bits were carefully saved as they can be melted down again become part of another casting.
And here’s the cleaned and tidied casting, ready for the hard work – filing and polishing.
(We did cheat a bit with the edges.)
Then it was time for the main labor of the day – hours and hours of filing, smoothing with sandpaper, and polishing with finer and finer grades of wet&dry to make a mirror finish.
This was hard, hard work, and unlike the bronze-age workers, we did it the easy way.
Another job was fitting the oak wood hilt. This is made in two pieces, and is first seared onto the re-heated sword tang, to help seat it. The tang then has four holes drilled, and the hilt fastened with four headless copper rivets. Then the hilt is shaped – more filing and sanding! Finally – a wipe-over with linseed oil.
Here’s the wood being seared into the blade in a clamp.
And then it was more hours of sanding and polishing, working down the grades, all the way to wet&dry 1200, then wire wool, and finally polish. Then an inspection for scratches, and start again. And again.
The reason for so much polishing was to remove the file marks and give the blade the appearance of a true bronze-age sword.
And it was worth it. they look beautiful:When all that was done, we gave the edges a deadly edge.
The blades are roughly 18″ / 45cm long, and the swords weigh 1lb 6oz / 644g.
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