How to make an arrowhead: A 101 on flintknapping

It's an obsolete technology that's been around for 3.3 million years.

It's an obsolete technology that's been around for 3.3 million years

Tim Rast is an archeologist who teaches at Memorial University in St. John's. (CBC)

Hunters nowadays use firearms or high-tech bowhunting equipment, but centuries ago — 3.3 million years ago, actually — the weapon of choice was an arrowhead honed by hand.

It's a practice called flintknapping, and while it's mainly fallen out of use, Tim Rast is a master at it.

Rast, an archaeologist and flintknapper, teaches at Memorial University in St. John's, and offers courses on how to make arrowheads the way ancestors did for millennia.

A small piece of leather can help protect your hand from the sharp edges of obsidian. (CBC)

"Today, stone tools and flintknapping are an obsolete technology," Rast told CBC's On The Go.

"So if you're an archeologist trying to understand and reconstruct people's lives based on an obsolete technology, it's really useful to understand that technology yourself."

Obsidian, a naturally occurring glass formed when lava cools rapidly, is the material of choice for making arrowheads.

Step 1: Make your flake

From a large piece of obsidian, you have to break off a smaller section to pare down to an arrowhead size, Rast said.

To do that, you use what he calls a hammer stone — an egg-shaped or rounded rock that fits comfortably in the palm of your hand.

Rast pressure-flakes a shard of obsidian to fashion it into an arrowhead. (CBC)

But you can't hit the obsidian just anywhere — there's a bit of physics to it, Rast said.

Look for a nice flat surface to hit it on; flakes like to travel along ridges, so position the hit above the ridge, knowing it will guide the shape of the flake.

Once your flake breaks off, use your hammer stone to brush up the edge and get rid of the leftover shards.

"Every time you take a flake off, it leaves a depression on the core, and you just wanna clean that up."

How can you tell a piece of obsidian was broken off in this manner? You'll see ripples that look almost like a vinyl record.

The cone of force on an obsidian flakes resembles the grooves on a vinyl record. (CBC)

"You find that on a beach, there's nothing in nature that creates that," said Rast.

"Just that flake alone will tell you that somebody was there working, somebody was flintknapping."

Step 2: Once you make the flake…

To make your flake into an arrowhead you need three tools, Rast said: a bit of leather to protect your skin from the sharp obsidian; the hammer stone to grind the edge; and a pressure flaker, like antler tines.

Rast said more advanced pressure flakers were used by some cultures, like the Dorset, who he said lived in Newfoundland about 2,000 years ago and would use a composite tool made up of a walrus tusk embedded into a piece of wood and lashed with sinew, most likely from caribou.

Rast says the Dorset in Newfoundland used a pressure flaker made of a walrus tusk embedded in a piece of wood, tied with sinew. (CBC)

Modern ones use a bit of copper in a wood handle. Rast said flintknappers use copper because it's a soft metal — harder metals would crush the edge of the obsidian rather than flake it.

Assume your obsidian flake is really sharp, so use the leather to protect yourself from cuts — a common woe for flintknappers. Then, you'll use the hammer stone to brush the edges.

"Get rid of the really thin, sharp edge by using our stone to brush down."

"We want a thin, sharp edge at the … end, but that thin edge is a weak edge, so we want to kind of strengthen it up. And this also makes it safer for us to handle it."

Make sure you brush down, not up, otherwise you'd be spraying glass fragments at yourself.

Step 3: Bit by tiny bit

Now comes the pressure flaking part of the task — the most time-consuming part of the process.

Find the thinnest part of the edge; hold the flake in your hand, with the pointed end toward you.

The tip of the pressure flaker, you find a low spot, put some pressure on it, flick down and detach tiny shards.

"You're trying to thin it, you're trying to shape it.… You want to work toward a triangle shape," Rast said.

And once it starts looking like an arrow…

How long it takes you depends on how familiar you are with the process, and exactly what kind of arrow style you want, Rast said.

Creating an arrowhead is a messy process, and a tarp to catch all the obsidian shards is handy. (CBC)

It takes him no more than an hour from start to finish to create a functional arrowhead.

You notch the wide end, attach it to the wood, and presto, you end up with an arrow.

To see the full process, check out this video with Rast:

With files from Tedd Blades and On The Go

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