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Friday, November 11, 2011

Make a Stone Age Bow Drill

You can expand your Stone Age tool kit by making a bow drill. The bow drill can be used to drill holes in wood or bone. To make a bow drill you will have to have mastered a couple of other skills first. You will need to be able to knap flint which was covered in my post on Making Glass Arrowheads Parts 1 and 2 on February 1 and February 8, 2011. You will also need to know how to make some cordage out of rawhide. Cordage making and the reverse wrap technique is covered in my post Primitive Bow Making Part 5 on February 24, 2009.

So, the first thing that we need to do is make a drill bit. Making a drill bit is pretty much like making an arrowhead except the shape is a little different. The actual drill part of the bit (the thin part that sticks down) can be whatever size you choose to make it. Just don't make the bit too thin or it will crumble. Bits should be made from hard flint, not from glass or obsidian. Pictured below: Flint drill bit.

In addition to the actual drill bit you will need a spindle, a hand hold, and a bow. If you have already made a fire-bow set you will have the hand hold and the bow and they will work fine for this project. If you don't already have these parts you will need to make them. This is what you will need:

A hardwood spindle - needs to be about a foot long and a three-eights to three-quarters inch in diameter depending of the size of your drill bit. The spindle needs to be smooth and rounded on the top so it will fit into the handhold and turn freely. Pictured below: Two different size spindles with bits already attached.

A hand hold - made of hardwood, stone, or bone. This has a shallow hole in it that will fit over the top of the spindle and allow it to turn freely. Pictured below: Hardwood handhold with spindle ready to be inserted in the hole.

A small bow - about two feet long, and one-half inch in diameter

A bow string - needs to be rawhide or braided nylon. Vegetable fiber cordage will probably not work. Vegetable fiber cordage will fray and come apart under usage. Pictured below: Small bow with rawhide bowstring.

Some pine pitch or rawhide glue - to help hold the drill bit into the spindle

Some wet rawhide or sinew - to help keep the drill bit in place on the spindle

Now let's put it all together.
1. Cut a notch in the bottom of the spindle that your drill bit will fit into.
2. Put some melted pine sap into the notch and push the drill bit down into the soft sap. Adjust the bit so that it lines up with the spindle. If it is cocked off to one side it will wobble when you spin the spindle, and this will result in either making a bigger hole than you wanted or breaking the drill bit.
3. When the sap has hardened, wrap wet rawhide or sinew around the drill bit and spindle to firmly hold the bit in place. Let the rawhide or sinew dry.
4. Saw notches in the bow and tie on your bow string. Don't make it real tight. The string is going to wrap around the spindle and this will tighten it up.
5. Wrap the bowstring around the spindle.
6. Place the drill point on the material to be drilled.
7. Hold the hand hold on top of the spindle with one hand.
8. Use your other hand to pump the bow back and forth and turn the spindle.
Pictured below: top, Flint drill bit attached to spindle with rawhide glue and deer sinew; and bottom, Drill outfit assembled and ready for use.


If everything is put together right you should be drilling away. A drill like this, with a stone bit, will not drill through something two or three inches thick. It will only drill the depth of the bit. If you want to drill deeper, you will have to make a longer bit; but a stone bit is fairly fragile, and sooner or later you will break a long bit or a short one for that matter). Pictured below: Freshly drilled hole in a pine board.

You can use just a hardwood spindle without a bit. This will smoke like crazy and wear down pretty fast, but it will drill/burn a hole.

If you have a piece of iron like an old nail, you can hammer the end of it flat, drive it into the bottom of your spindle and it will make an excellent drill bit.

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