Primitive Survival Bow-Drill

by Peter Moc
(photos by Peter Moc except where otherwise indicated)

This is by far, the most challenging facet of learning the bow-drill. Without a knife or cordage, the construction of a set can take several hours longer. Much more time is spent looking for pieces that must be just right. Most of your time will be spent walking around. Another chunk of your time will be spent bashing and grinding wood and stone. Much more energy is required to create the coal, and the reliability of the set and your ability in producing a coal is less than with a knife and cord. However, the rewards of giving birth to a coal in the purest form are worth it, even if you never you use it in a survival situation.

Barry Keegan is the authority on natural materials for cords and if you want an intensive coverage of this subject than please take a look at his article. This will be a more general discussion and will only include the more reliable materials and methods. In terms of plant materials, there are three main classes of potential cordage material. These are: roots, tree/shrub bark and herbaceous fibres.

Roots

The successful roots are generally those from the coniferous trees, such as pine and spruce. Deciduous trees do not seem to have strong enough roots for bow-drill cords but there are exceptions. As with trying out different woods, you should make a habit of digging up a root (a little less than pencil thickness) from a new species and testing it by trying to break it with all your strength. If it doesn’t snap than you should experiment with it further.

To prepare a root for use as a bow-drill string, just dig it up, being careful not to break it. It should be about pencil thickness, straight, and with little taper. Try to avoid roots that have major branches. Try to get a root that is at least one and a half times the length of your bow. Carefully remove and root hairs and “saw” the root around a tree branch to abrade a seam in the root’s bark. Carefully peel away the bark and wipe off the sap. Tie the ends of the root as you would for a normal string and load it into the spindle. It will be harder to load than a regular string because of the stiffness of the root so just ease it in. Any small roots can be used for tie-off cordage on your bow splits. Use clove hitches as these are easily to tie with stiff, bulky cordage.

Start stroking as you normally would, but make sure you keep the bow pointing down away from you. If the bow is perfectly horizontal, the root will rub on itself and abrade much more quickly. Keep the root moist between uses. If the root dries out it will immediately snap when used again. If it does dry out, you will have to soak it to make it pliable again.

Tree/Shrub Barks

Barks require a little more preparation then roots. You will need to peel off the bark without ripping it. This is easiest in the spring and summer. First, find a relatively straight, long branch. It should be about the thickness of your pinky finger. The longer it is, the better. It should be twice the length of your bow. Also, make sure it has no scars or dead sections. Cut it off the tree and remove any small branchlets. Using your knife or by pounding an end with a rock, start a split. If the branch is curved, split it so that you end up with two flat halves (i.e., along the flat plane). In order to split it without breaking the wood, you have to keep the split even on both sides. If the split starts to run off to one side, pull more on the thicker half. Also, don’t pull back on the halves, try to keep them straight. One way of doing this is to put the unsplit end under your armpit and carefully use both hands at once. You can also push your thumb into the split to move it along.

Once it is split, remove the bark in the same manner. It is not important if the wood breaks during this but do not break the bark! In other words, you can pull more on the wooden half than the bark half. Keep the bark half in a straight line.

If the bark doesn’t want to peel than you can pound on it with a wooden stick. Use a smooth stick and anvil. You can really hammer hard and pay special attention to areas around knots/branches as they tend to stick if not hammered.

The two halves can then be reverse wrapped. You can also just simply twist them together. This is faster but not as strong. It is also a little more difficult to handle as the fibres are just loose. You may want to remove the outer bark at this point as it can be quite bulky and stiff on some trees and may wear out the string prematurely. Tie each end into a half-hitch and use as normal. Use the same technique as for roots. Any leftover bark can be used as tie-off cordage for the splits in your bow. Again, use clove hitches.

Make sure you wipe down the string before use. A damp string actually increases the grip on the spindle, which is very helpful. If the string is too wet or slimy, however, it will slip badly. Also, letting the string dry out a bit reduces that mushy sensation. This will absorb a lot of your energy. The thinner your string, the less energy this sponge effect steals away. Of course, strings can only be made so thin before they are too weak. Thick strings will be strong enough, but getting a coal will be next to impossible because the string will absorb all your energy. Also, the spindle will go through fewer rotations per stroke because the string is effectively shortened by its own girth. The maximum string thickness I would use would be about the diameter of my pinky finger. Anything thicker just sucks up too much energy. As with roots, bark strings must be damp when in use or they will break.

The key to using successful bark strings is the type of species the bark comes from. Basswood and hickory are very good. American elm will also work. Mulberry has been known to work. There are many trees to try. Next time you are out in the woods, cut a small branch of about pencil thickness and peel it as described above. Wrap it and try breaking it. If it is very difficult then try making a full string from it. Make this sampling of barks a regular habit.

Fibres From Herbaceous Plants

Finally, there are the herbaceous fibres. These include dogbane, nettle, milkweed, etc. These are best used in the fall when the fibres have fully developed. Remove the fibres using the same technique for barks. Generally, the stalks will already be dry so pounding will do little good, instead damaging the fibres. Just crush the stalk so it splits. Open it up so it is a flat strip and break off short sections of the woody core, starting at one end. Make sure you get all the woody bits out or they will cut into the string in use. After cleaning the fibres, reverse wrap them and splice so your cord is about one and a half times the length of your bow and about pinky thick. You can dampen the string to increase the grip on the spindle.

It should be evident that you will be forced to use a bow that is shorter than the ideal length. This is particularly true for bark strings, which don’t splice well. Try to make your bow as long as you can without having to compromise on the string. If the bow is long and you have to include weak sections of cordage to cover the length, you well just end up with a broken string.

Stone tools can be categorized into the purpose they will serve. For example, abraders, drills, etc. For a bow-drill you will need a chopper, abrader, carver, and gouger. The abrader may take the place of the chopper and the carver. A carver may not be needed if you have a chopper and abrader. The gouger is not really necessary. You could substitute a piece of hard wood instead. The following techniques work best with the softer woods.

The chopper is any rock with a fine grain. It doesn’t have to be a particularly tough rock. It should be shaped roughly like a teardrop. One end should come to a point and the other end should be a rounded bulge. Basically the same thing as the ancient hand-axes. The more weight it has, the better. Of course it shouldn’t be so heavy as to tire you out after a few chops. It should fit comfortably in the hand if possible. Usually, you will have to make due with cobbles that are about the right size and flake off sections to produce a crude blade at one end.

A wide variety of rocks will work. Limestone is relatively weak, but easily worked. It should hold together on soft woods. Andesite and other fine-grained igneous rocks, such as basalt, are a good choice. These will be more difficult to work, especially if all you have are rounded river cobbles. Cherts and flints make good choppers if you can find pieces big enough to use. Stay away from rocks that crumble easily, like shale and sandstone. Granite is generally too coarse-grained although it is worth trying. Obsidian is way too brittle.

The technique of using hand-axes is simple. Just smash the section of wood you want to shape. Use a sturdy log as a workbench. Focus the direction of the blows along the grain of the wood. In other words, don’t chop straight down. Chop at an angle to the branch. The effect is to push and pulverize the wood off in the direction of least resistance - the grain. It isn’t pretty but it works. As you pound the wood, it will separate along the grain and you will be able to peel off short sections of the annual rings (also known as splints). Keep pounding hard until you have gotten through enough to make a controlled break. The angle that the cut will have will be huge compared to an axe because the blade on the rock must be so thick to avoid crumbling.

Generally, the only time you need to do this is for the ends of the spindle. You will need to start with a branch that is already the diameter you want your finished spindle to be, otherwise it will take forever to whittle it down.. It must be straight. Make sure the ends of the spindle taper roughly to points. You will finish tapering the ends with either an abrader or a carver.

The abrader can be virtually any type of rock. Obviously, something glassy, like obsidian, won’t work. Sandstone is probably the best. Gneiss and sometimes granite will work. This is used like you would use a file. You can also use abraders more like saws if they are shaped right. The ends of the spindle, the notch, and the ends of the bow can be shaped/cut using an abrader. For the notch, you will need a thin flake. The ends of the spindle however, can be abraded against exposed bedrock or a large slab.

Carvers are rocks that hold sharp edges. These are typically the cherts, flints, and obsidians, among others. These are more useful as fine-shaping tools. The choppers will produce a quick, messy end that needs to be cleaned up. Carvers allow very nice whittling to be done, but take too long for any bulk work. Using simple, hard-hammer percussion, break off some small flakes from a core and replace when they get dull. Make sure you don’t twist the flakes as you push them into the wood or they will crumble. Take off little shavings of wood until you get the shape you want.

Gougers are just any type of rock that doesn’t crumble easily and holds a rough point. These are just hand-held drill bits. Use these to start the holes in the handhold and the board. Really, anything can be used for this, such as antler, bone, or even a piece of hard wood.

One way of shouldering the end of the spindle without a steel knife if to chop just the last couple inches. Instead of chopping at an angle, chop straight down. This will cause the growth rings to separate and you can peel them off until the end of the spindle is the diameter you want.

The bow is made as with a knife, with a few changes. Since you will not have a thin blade to wedge into the ends to start the splits you need to do this differently. When you are removing the bow limb from the tree (remember, it must be green), only cut/abrade/chop half-way through. Then, carefully split the branch by pulling it away form the cut. Then cut/abrade/chop through the other half to separate it from the tree. The other end can be done in a similar way. Make sure you keep in mind the orientation of the bow and the split. You want the split to be in the same plane as the bow so make your initial cut accordingly.

The board should be quite thin, about the thickness of your pinky. The string will simply not be able to handle the torque of spinning a spindle in a deep hole.

The notch should not be made too big or the spindle may pop out. You will probably have to make a new hole and notch each attempt.

The handhold can be made from one of the pieces you rejected when trying to snap out a board from a thick branch. The shape of the handhold is not important, as long as it doesn’t get in the way of the bow. Don’t bother cleaning up the ends, you just waste time.

Try to make the handhold hole using the rock as much as possible. Burning both ends of the spindle at once puts a lot of strain on the string and your arm. Sometimes you can skip the handhold burn-in completely if the hole is big enough and it matches the spindle tip. Remember, make the hole nice and deep to prevent the spindle from popping out. Making the end of the spindle into a fat half-sphere reduces unwanted burning.

If you let the string dry out, you will have a greater chance of getting a coal. You don’t want it completely dry. It is almost always easier to get a coal if you let the cord dry out overnight and then re-hydrate it the next day. That sponginess is thus greatly eliminated. This may not be feasible in a real situation though.

Putting all the parts together in the forest is not a simple or easy task. If you cannot find any rocks to use, what can you do? This is a very real possibility in some places. Also, a covering of snow and frozen ground pose serious problems if you were to depend on getting a fire from scratch in a real survival situation. You are looking at an average of half a day to find and make all the components of a bow-drill set and this is in favourable conditions! It is much easier and faster to make a fire using bow-drill if you have a steel knife and some strong cordage to use. Even a partially-reliable full survival bow-drill set requires many hundreds of hours of practice to produce a coal on the first attempt, from scratch, in the bush.

Even so, actually being able to give birth to a coal without relying even one bit on the tools of civilization is a feeling that hits you like a truck. You are taking the bow-drill to its purest form. There is a direct communication between the natural materials that went into it and yourself. It is not something you will ever forget!

© 2000 Peter Moc