by Peter Moc
(photos by Peter Moc except where otherwise
Introduction to Bow-Drill
When you are first learning bow-drill
fire-making, you must make conditions and your bow drill set such that the
chance of getting a coal is the greatest. If you do not know the feeling of a
coal beginning to be born then you will never be able to master the more
difficult scenarios. For this it is best to choose the “easiest woods” and
practice using the set in a sheltered location such as a garage or basement,
etc. Remember to unplug your smoke alarms!
Even if you have never gotten a coal before, it
is best to get the wood from the forest yourself. Getting it from a lumber yard
is easy but you learn very little. Also, getting wood from natural sources
ensures you do not accidentally get pressure-treated wood which, when caused to
smoulder, is highly toxic.
Here are some good woods for learning with (and
good for actual survival use too):
Eastern White Cedar
Aspens and Poplars
There are many more. These are centered more on
the northeastern forest communities of North America. A good tree identification
book will help you determine potential fire-making woods. Also, make it a common
practice to feel and carve different woods when you are in the bush. A good way
to get good wood for learning on is to find a recently fallen branch or trunk
that is relatively straight and of about wrist thickness or bigger. Cut it with
a saw. It is best if the wood has recently fallen off the tree. Willow and aspen
often break off limbs, especially in ice storms. If no green wood can be found,
then use solid dry wood. Cedar can often be found in pretty good condition as
standing skeletons. Avoid sections of wood with lots of knots and wood with
cracks in it (checks).
Once you have a good section of wood (the more,
the better), split it in half with an axe (or knife) to let it dry. A branch the
diameter of your fist and a couple of feet long is a good size to work with. You
want to have lots of material to experiment with as you burn through boards and
spindles. Let the wood dry for about a week in the sun if possible, longer in
the shade. Now you can make your set.
A Note on Knives
Make sure you have a comfortable knife to work
with as this will make things more enjoyable and safer. I suggest a light knife
with a blade of about 1/16" thickness. Thinner blades require less effort
to be pushed through wood. Avoid knives with finger guards as these just get in
the way. A relatively short blade (about 3") is easier to work with. The
handle shouldn’t have any sharp, boxy angles or uneven surfaces. Keep your
knife sharp. Many knives will do. Mora knives form Sweden are very nice and
inexpensive. Don’t hesitate to use the ground as a work surface for bracing
the wood against. The more stable the wood you are carving is, the better.
|The Mora-bladed knife.
Easy to use, high quality blade steel, and inexpensive too!
Making the Set
There are five parts to the bow-drill set. The
bow, the string, the spindle/drill, the board, and the handhold. The drill spins
against the board on one end and is held vertically by the handhold at the other
end. The drill is spun by the bow and string.
The following describes how to
carve the components of a beginner set from a larger chunk of wood.
Taking the once-split branch, cut it with a saw
or whittle and snap it into a foot long length. Using an axe or a knife and
baton (a short, sturdy branch for hitting the back of knife blades) combination,
split the branch evenly down the middle. Keep splitting until you get a flat
board that is about one inch thick, or the thickness of your thumb. Whittle it
down to remove any protrusions so you end up with a flat, straight-sided
rectangular shape (this isn’t very important). The board should be about three
inches wide, but anything greater than two inches is fine.
Take a foot-long straight-grained section of
wood (if possible, from one of your previous splits) and whittle it into a
slightly less than one-inch diameter straight dowel. In other words, the dowel
should have the same diameter as the first knuckle of your thumb. Whittle the
last inch of each end into sharp points. The fatter the spindle, the less wear
it places on the string, but a longer bow is required to result in the same
amount of rotations taken per bow stroke. Essentially, this works the same way
as the gearing on a bicycle.
Take the other half-split branch and saw off a
section approximately four to five inches long. Whittle down the edges to remove
any rough spots and to provide a comfortable surface for gripping. On the flat
side of this, exactly in the center from all four sides, gouge a hole with the
point of your knife. Make the hole about half an inch deep. Make the sides of
the hole slope out at a 45 degree angle so as to form a cone shaped depression.
There are a wide variety of materials strings
can be made of. These include: nylon, cotton, jute, leather, rawhide, buckskin,
and a wide variety of wild plants. In general, use a string that is at least one
and a half times the length of your bow. The string should be relatively thick.
A thickness of a quarter-inch will last a long time. Shoelaces are usually not
thick enough for repeated use. Cotton hockey skate laces will do. It is best to
avoid synthetics such as nylon as they sometimes melt from the friction unless
thick enough. Thick cotton cord is just about ideal for repeated use.
Find a section of a green (live) branch that is
about the thickness of your index finger and almost straight or slightly curved
and the length of your arm from elbow to fingertip. The bow should be reasonably
flexible but not flimsy. It should not want to bend more than two inches from a
straight line when flexed using a little strength. If it bends too easily or is
prone to snapping, find a slightly thicker branch or use a denser wood. If it
hardly bends at all then you can carefully whittle off a little wood on the
inside of the curve. Make sure it bends evenly to avoid weak spots. The
flexibility of the bow is important in the overall feel of the set. If the bow
doesn’t bend, the string will slip frequently and soon break. If the bow is
too flexible the string will also slip and you won’t be able to apply the
torque that is required.
Split the first two inches of each end of the
bow with a knife. This is why you need a green branch. A dry branch will not
split properly. Make sure the split is even and doesn’t run off to the side.
The orientation of the split is very important if the bow has any curve.. When
the bow is set on a flat surface, the splits should be parallel to that surface.
Take two short lengths of cordage and snugly tie them around halfway up the
splits. Use square knots of some other knot that will not work loose.
The clove hitch is very good for this. Tie one
end of the bowstring into a knot. Set this end into the split in the bow so the
knot is on the side of the bow that is curving away from itself (convex). Make
sure that the string is held tightly by the split by moving the short section of
cordage up the split toward the bowstring. This will effectively tighten the
split. Take the other end of the bowstring and repeat on the other side. The
amount of slack in the string is something that must be adjusted through trial
and error when you fit the spindle. For now the string should be somewhat loose
or you won’t be able to load the spindle.
Technique & Form
If you are right-handed, hold the bow with this
hand. Place the board flat on the ground so it is stable. Take your spindle and
push the point into the board so that you make a mark. This mark should be about
one full spindle width from the edge of the board (about an inch). It should
also be at one end of the board so that you have room to place your foot. With
your knife, gouge a shallow hole similar to the one in the handhold.
The bow is tilted slightly down
to avoid rubbing the string against itself. Also, the stabilizing of
the left hand against the shin is very important.
Now, put your left foot on the board (if you
are right-handed) so the inside ball of your foot is next to the shallow gouge.
Your right knee should be on the ground and you should be sitting on your right
foot. Your right leg should be parallel to the board. Another possibility is to
raise your butt off your foot and lean your chest on your left knee -use
whatever works for you.
Load the spindle by wrapping the string around
the spindle so that the spindle is outside of the bow. This may require some
adjusting of the string. The spindle should feel like it’s going to pop out.
The tighter the string becomes, the better, just don’t make it so tight that
it breaks the bow. Holding the loaded spindle and bow in your right hand, place
the bottom point of the spindle into the hole in the board. Cap the other end
with the handhold and apply some pressure to keep the spindle from popping out.
Let go of the bow. The bow should be pointing itself up towards you. If it is
pointing down, reload the spindle so the bow is pointing up.
Make sure the spindle is on the
opposite side of the string to the bow. Otherwise the spindle will
knock against the bow while stroking.
You can now begin the “burn-in” process.
This is to form the handhold hole. Simply begin stroking the bow back and forth
slowly. Keep the pressure on the handhold fairly high. Eventually, you should
see a small amount a smoke forming at one or both ends of the spindle. Pick up a
little bit of speed until both ends are smoking. It is most important that the
handhold end smoke at this point. If it refuses to, even when you pick up the
speed and push down harder, reload the spindle so the top is now the bottom and
vice versa. Repeat until the handhold starts to smoke. Keep going until the hole
in the handhold is the same diameter as the drill. It should match the curve of
the drill point exactly now.
Now you must lubricate this end (keep track of
which end is up and which is down!) This is to keep it from smoking and taking
away your energy so all your power can be focused on the lower end. Unload the
spindle and rub the top into the hole in the handhold. Blow off any dust. Push
the drill into the handhold as hard as you can and slowly rotate the drill.
Again, blow off any dust. Now, rub this end into your hair and along the sides
of your nose. This is to transfer the natural oils found on your skin onto the
wood. It helps if you haven’t showered for a day.
Repeat the pushing-in procedure. You may want
to push the end of the spindle against a smooth rock. This effectively hardens
the end of the spindle by compressing the wood. To baseball players, this is
known as “boning”. Repeat the pressing of the spindle into the handhold hole
and rubbing the tip into your hair until it develops a sheen. Keep all moisture
away from this as it will cause the wood to expand and it will bind in the
handhold causing friction and burning. You want the frictionless end of the
spindle to be very rounded. This distributes the pressure forces over a greater
area reducing the tendency of the spindle to drill up into the handhold. If you
imagine an electric drill, a small bit will require less effort to drill through
a material than a very large one. We want to prevent the drill from burning at
this end so we use a large surface area.
Cutting the Notch
You must now make a notch in the board next to
the “burned-in” hole so the ground-off powder has a place to accumulate.
Take your knife and scribe a 45 degree angle in the top of the board that
originates form the center of the hole. The two lines will go to the closest
edge of the board. Cut out the wood in between these lines so that you have
removed about a one-eighth fraction of the burned-in hole. This slice should go
all the way to the bottom of the board so that you have removed a wedge of wood
on one side of the board pointing to the center of the drill hole.
Getting the Coal
Place something under the board where the notch
is to catch the coal. This can be paper, birch bark, etc. If you are on a floor,
the coal will melt it so keep that in mind. Put yourself into the position
explained earlier and begin drilling. Be sure to put the lubricated end of the
drill in the handhold. You can now begin the first stage, “powder”.
Drill slowly and with firm pressure until the bottom end begins smoking. Keep
the smoke down to just a wisp. You should see powder accumulating in the notch.
Keep this slow pace until the notch is just about filled. Now lighten the
pressure and drill very fast. This is the “heat” stage. The idea is
to make heat, not powder. It should begin to smoke heavily. If not, apply a bit
more pressure until it does. Keep going until you are totally surrounded by
smoke. At this point, stop drilling and carefully remove the drill. If there is
smoke coming from the powder pile for more than a few seconds you probably have
a coal. Gently blow on the coal until it begins to glow red. You may now
transfer it to a tinder bundle. This is simply a fist-sized bundle of dry
grasses, fibrous inner bark of certain trees, etc. Blow on it until it flames
Sometimes you can skip the powder stage
and just go for the heat. This is usually when the wood is very dry, soft, and
easy to work with. Every piece of wood is different, even from the same tree.
Reading the Powder
If the drill begins smoking in the handhold end
you will have to re-lubricate it. You may have to switch the ends of the spindle
as one end may be slightly harder than the other. Another solution is to “shoulder”
the lower end of the spindle. This is simply reducing the diameter of the last
inch or so of the drill. This results in less pressure being needed to drill the
spindle into the board. This often solves the problem of the handhold burning as
well as the problem of the lower end of the spindle refusing to start burning.
Problems can often be solved by looking at the colour and consistency of the
Remember, the suggestions below are for the powder
stage. The heat stage should produce the least amount of powder with the
most amount of heat. In other words, you should be pushing down enough only to
make lots of smoke, but no more powder. If you push down too much you run the
risk of making crusty powder and pushing all the good powder you so carefully
made out of the notch. This is not so important with dry, soft woods, but is
very important when using damp or slightly harder than ideal woods.
Going too slow, not pushing
down hard enough
Going too slowly
Difficult, sometimes going too
fast & not pushing down enough
Pushing down too hard, going
(see photos below for examples of each type)
Colour is associated with speed. Light brown
means there is not enough heat being generated, hence you must drill faster.
Black means there is plenty of heat generated although you have to be careful
not to push too hard. Consistency is associated with downward pressure. Dusty
means tiny floury fragments are being ground off. This isn’t so much of a
problem in itself, but it usually occurs because there is not enough pressure
down and not enough speed. Fuzzy is perfect. This provides the most
amount of surface area for combustion to take place. Crusty means there is too
much pressure down. This usually occurs in combination with too much speed. This
powder will not ignite easily because there is little surface area for
combustion reactions to take place.
Light brown, dusty
Light brown, fuzzy
This will usually allow you to adjust your
technique and get a coal. Sometimes however, this isn’t possible. For
instance, if you are pushing down as much as you can and still getting dusty
powder or hardly any powder at all you have done all you can with technique.
Your next option is to shoulder the spindle down a little more as was mentioned
before. This way the set will require less downward pressure to produce more
powder allowing you to fill the notch with the same amount of strength. A
downside of this is that the set becomes more sensitive making it easier to push
If the problem seems to be not enough speed,
there are a couple things you can do. First, you could make another spindle this
time a little wider. The wider spindle will generate more heat because the edges
of the drill will be traveling faster than the narrower spindle. The second
option and probably better is to use a longer bow. This may or may not be of
help, depending on how long your bow already is. This allows you to reach higher
speeds by taking longer strokes, resulting in less time spent stopping and
starting the bow.
Finally, there is the problem of getting powder
in the form of little rolls. These look like the rolls you would get after using
an eraser. Sometimes these happen because the wood is somewhat damp. Other
times, you get these when the wood is a little hard. The best way to approach
this, in my experience, is to shoulder the spindle down a bit, build up a good
pile of powder (whatever it looks like), and just try to make as much heat and
smoke as you can. Usually this results in a coal, but if you are already tired
it can be very difficult. (See photo below)
It is very important that the fundamentals are
learned before attempting the more advanced techniques. If you don’t learn how
to read what the wood is telling you, your coal-producing reliability will be
unpredictable in the more difficult scenarios. You should be able to get a coal
nearly every time you try when using a proven set before you move onto
made-from-scratch bow-drills. Keeping a notebook of your experiences and
experiments will greatly aid in advancing your ability.
© 2000 Peter Moc