History of Technology 4: How is Bronze Made?

We know what question keeps you up at night: how is bronze made? ...No? You've never thought about that? ...Huh. Well...good for you.

LanguageEnglish Language
TechnologyHistory of Technology

Transcript

00:17

It has to be intentionally made by humans.

00:20

People couldn't just whip up a batch of bronze on a leisurely Sunday afternoon. [Woman in kitchen making bronze]

00:24

First, we need copper.

00:26

And through a little movie magic…boom.

00:28

Copper.

00:29

Done.

00:31

Then we need another natural metal called tin. [Several empty tins]

00:34

And believe it or not, ancient folks couldn't just root around in their cupboards for tin [Caveman opens a cupboard to find tinfoil]

00:38

foil…

00:39

…they usually only had Saran wrap back then.

00:42

But most major centers of civilization did manage to trade or mine it. [Man trading cattle for tin]

00:47

So after we have our copper and tin ready to go, we need to mix them together.

00:52

That means that both metals have to be heated to blistering temperatures. [Woman puts copper and tin in a mixing bowl]

00:55

We're talking 1000 degrees, which is roughly the temperature of soup after we try to microwave [Soup in a microwave]

01:00

it.

01:01

This turns them into liquids.

01:03

The two liquids can then be mixed and poured into molds to cool.

01:08

Like Jello molds…

01:09

…but deadly.

01:10

Sometimes those molds were the shape of the final product, like daggers or shields. [Collection of daggers and shields]

01:15

And sometimes the molds were just generic blocks that could be heated and reworked later.

01:19

No word on whether or not they used the always-classy poop emoji mold. [Woman pouring molten bronze into a mold]

01:24

So there are several reasons why bronze rules and copper drools. [Bronze looking happy and copper looking sad]

01:29

First of all, bronze is way harder, its a firmer metal.

01:31

Seriously, bronze is just as hard as early iron, which made it the perfect material for

01:36

hacking apart your enemies limbs. [Man chucks a bronze sword and kills 3 soldiers]

01:38

…We said that more cheerfully than we meant to.

01:41

…We promise, we're not sociopaths.

01:42

…Moving right along…

01:44

Bronze doesn’t corrode. [Bronze statue]

01:46

Copper corrodes like crazy, and even iron rusts. [Copper looks worried as it begins to corrode]

01:49

That's why most sculptures you see in parks are made out of bird poop. [Statue covered in bird poop]

01:54

…Oh, and bronze.

01:56

Sometimes it's hard to see underneath the layer of poop.

01:58

Alright well here’s the kicker…

02:01

Even though bronze was a much harder metal, all the copper in it made it more flexible [Iron gets tired doing jumping jacks and copper carries on]

02:06

than iron.

02:07

That meant it was less likely to snap or crack under pressure. [Man snaps his back doing yoga]

02:12

Unlike us.

02:13

…Seriously, we're not sociopaths…

02:14

So why didn't everyone run out and get a grab bag of bronze weapons? ['Bronze' handing over a bag of bronze weapons to a kid at a birthday party]

02:19

Like most things in life, it was all about the Benjamins.

02:22

Bronze was just too expensive. [Man looks shocked at bronze receipt]

02:25

Copper wasn't cheap, but there was a lot more of it lying around.

02:27

Plus, tin was rare enough that long trade routes crisscrossed the Old World just to [Man chucks a spear at a wild boar]

02:32

support the tin trade.

02:34

And to top it all off, the process of making bronze required oodles of skill, time, and [Man working on bronze]

02:40

fuel to make a 1000 degree fire.

02:42

They couldn’t just stick it in a microwave back then.

02:44

Which…come to think of it…would’ve been a bad idea for multiple reasons. [The microwave explodes]

02:49

All these things meant that arming an entire army with bronze weapons was pretty pricey.

02:54

Actually…scratch that: it was impossible.

02:56

Sorry, to crush anyone’s bronze army dreams.

02:57

Now if you'd excuse us, we're going to go see how expensive a poop emoji jello mold

03:01

is….

03:02

….don't judge us, it really does sound hilarious. [Man pouring molten bronze into the poop mold]