Fire Making with Bow Drill
The basic idea
By rubbing two pieces of wood together quickly, you create enough heat to burn the wood – not to a flame, but to create a hot, black dust.
A piece of wood (spindle) is rotated rapidly whilst pressing its tip into a second piece of wood (fireboard) at 90 degrees to its grain. Both the tip of the spindle, and the hole worn in the fireboard by friction, will be blackened by the heat. A small notch cut into the hearth will allow the hot black powder to be collected.
The heat will cause the wood to smoulder and smoke. Collecting the black powder into a small pile in the notch keeps it together and hot. This powder, if hot enough, will continue to smoulder and smoke, even after you stop rubbing the wood. This delicate pyramid of black dust (called an ember or coal) is the source of your fire. It should be smoking and may be slightly glowing orange. It must then be carefully placed into the centre of a pre-made “nest” of fine, dry tinder – without breaking it or losing its heat.
For fire you must have:
· fuel (tinder)
· heat (ember)
· oxygen (air and breath)
Despite the exertion of creating friction, it is essential to be calm and not rushed. The nest must gently cocoon the delicate ember so as to keep the heat in (like a baby) but not smother it (you must allow air to reach the ember). As heat rises, make sure you have the tinder above, as well as around, the ember.
By keeping very gentle pressure on the tinder nest, a slight contact can be maintained between the finest tinder that surrounds the ember. This is an ‘extender’, heated by the ember and it too begins to smoulder and grow very hot. The size of the glowing ember is therefore increasing and the heat grows larger and more intense, aided by a little oxygen. Too much air will cool the ember, so it must be treated gently.
As the whole tinder nest becomes hotter it begins to smoke liberally. Now you increase the air by breathing long and steadily onto the glowing orange ember and the now-glowing tinder. If all is done correctly and you have enough tinder to last to this point, it will ignite into flame.
Once a flame is started it will normally continue to burn reliably. This burning tinder is immediately added to a pre-made fire of fine kindling. The fire must still be gently coaxed and adjusted until fully alight by arranging the fuel so it can be heated and still get enough air to burn.
Preparing your materials
The Kit consists of:
Bow: curved, rigid wood with a cord tied to both ends
Spindle: completely straight and no longer than the span of your hand
Fireboard: with a slight depression (hearth) and a narrow v-notch
Hand-block: of wood, stone or shell, to hold top of spindle and protect your hand
Leaf: or leather or suchlike to collect the dust in the notch
Lubricant: to reduce friction in the top end of spindle (green leaf, grease, etc)
Tinder: dry and of various sizes – from very fine to small.
The right combination of woods for spindle and hearth is critical.
A wide variety of woods have been successfully used to make fire in Scotland, as demonstrated by Patrick Cave-Brown in 1986.
In general, medium soft woods work best, such as hazel (spindle) and pine (fireboard hearth). A debate continues to smoulder about using the same wood for both. Current vogue is that wood from the same source, rubbed at 90 degrees is a good combination. Certainly you don’t want a hard spindle and soft hearth or you will too quickly drill a hole.
Use the rule of thumb – a spindle about as thick as your thumb, a fireboard about as deep as your thumb and a depression (hearth) with its centre about your thumb width from the edge (easier for the notch to be cut).
Measure in a thumb width from the edge of the fireboard and make a hole with a sharp knife, bone etc. Carefully widen this hole to the diameter of your spindle and of shallow depth (just enough to seat the spindle).
The end of the spindle that is to create friction is the “working end”. This should be cut in a shallow angle to fit snuggle into the hearth and have its entire surface in contact with the bottom of the hole. It will thus look very blunt and slightly rounded (like the end of a broom handle). Keep this end dry and free of grease!
The opposite end of the spindle wants minimal friction, to rotate freely and not get too hot. In addition to using lubricant, cut its tip to a more pointed shape, resembling a blunt pencil.
By seating the spindle into the small hole in the fireboard and bowing gently, the two woods become worn to a matching shape (married), slightly burnt and ready to be used properly.
Only once the hole (hearth) has been established should you cut the v-notch that is to gather the wood dust. The notch want to only be about 45 degrees (a 1/8th wedge) and only reach to the centre of the hole. Too wide or too deep and insufficient wood is left to get worn by friction. Too narrow or not cut deep enough and it will choke up and not collect the dust. Cut the notch by marking an imagined centre line from the hole’s centre out to the fireboard edge. Take small cuts either side of this imaginary centre line, bit by bit, eating into the wood towards the hole. Once the v-notch is cut, smooth its edges to reduce the chances of the dust sticking to it.
Assembly and posture
Place the fireboard on the ground, notch preferably facing you and with the leaf beneath the notch. The notch and hearth should be to the right of your foot (ie closer to the bow). Wrap the cord once or twice around the spindle so that it is very tight, gripping the spindle. Make sure the spindle is “outside” the line of the cord, so not to be impeded by the bow. Locate the working end of the spindle into the hearth depression and hold in position with the hand-block.
You will now have the bow gripped at one end by your right hand, your left hand holding the hand-block and keeping the spindle located in the hearth, your left foot holding the fireboard.
Your body form when bowing is essential. You must be balanced and comfortable – able to operate the bow continuously for some minutes whilst maintaining a firm downward pressure on the spindle and be able to keep the spindle quite steady. One foot must firmly hold the hearth down on the ground so it cannot move.
If right handed you will best hold the bow in that hand. Thus, place the arch of your left foot firmly onto the hearth about 2 cms from the hearth. Kneel on your right knee so that your upper body weight is over the fireboard and your left shin vertical. Place your right knee inline with your left foot and turn your rear foot (right) to one side, thus making three points of balance for stability. You want to be steady as a rock, yet able to subtly adjust your downward pressure on the spindle and able to make long, flowing bowing, slow at first, faster at the finish.
Brace you hand holding the hand-block against your shin, preferably by wrapping your arm around your leg and resting your wrist beneath your knee. Use the larger muscles in your leg, and your bones to hold the spindle vertical and steady throughout. If it wobbles too much you lose contact between the woods and hence friction. The spindle must be held firmly all the time, and be pressed quite firmly into the hearth.
How to operate the Bow Drill
First, think about your goal – making fire – and visualise it. Make clear your intention to light fire and if you choose, consider the sun god and call down a piece of the sun to make fire.
Ensure all is prepared ready and positioned to hand – the tinder nest, spare tinder and a twig or knife to help move the fragile ember out of the notch, where it tends to stick.
Do not rush – this is not a race. It is about style, form and technique. It is preferable to bow barefoot, not just to look more authentic but to feel the board and any movement. As with the hand holding the spindle, you want to sense any juddering or slipping. A bare foot also grips the wood far better. Use your foot!
Remember – good form and focus can overcome all sorts of difficult conditions. Good materials will not make fire, by themselves. Practice & persevere.
Start with long, smooth strokes of the bow, fairly slowly but still firmly, whilst holding the spindle steady in its hearth. Maintain a steady bowing, ensuring the cord is tight and rotating the spindle well. As your woods become hotter, increase downward pressure to increase friction further. This extra resistance will make it harder to turn the spindle so the cord is more likely to slip. If the cord is slipping you can grip it with your bowing hand to tension but if this does not remedy it you may have to stop and shorten it. As the cord heats up it may stretch – so start with a very tight cord.
If the wood is screeching it is either because the wood is slightly damp or you need more friction by increasing downward pressure. Occasionally the wood surfaces can become polished – this will need roughing up before restarting.
With good form and technique smoke will start to rise from the now hot hearth. Increase downward pressure slightly and continue bowing until smoke is billowing out. You need to build up enough dust to the top of the notch. With smoke billowing from the hearth continue for at least a further 30 strokes, slightly reducing the downward pressure and increase your bowing speed. If you stop too soon you must start again from the beginning!
When you stop you will likely be out of breath. There is no need to hurry but be careful to not disturb the fireboard or knock the fragile pile of dust. The dust should continue to smoke freely. It is worth allowing it time to coagulate or melt into more of a lump because of the heat within it. Take this time to regain you breath and composure – now begins the delicate part!
Use a tiny twig or knife etc to hold the ember to the leaf / leather whilst carefully lifting away the fireboard. This is the most delicate part of the whole fire lighting. Be gentle to avoid disturbing the dust because if it crumbles at this stage you will drastically cool it by exposing it to cold air. Placing the twig into the tip of the notch and rotating the board away seems to work.
You now have a pile of smoking, smouldering dust on a leaf. A gentle moving of air or a very cautious breathing should cause it to glow slightly but this is not necessary.
Having calmed yourself down and caught your breath you can place the ember into its nest of downy tinder. This enforced pause also helps the dust combine and form a more solid lump. Gently place this ember, don’t drop it. Also then add to it any other hot dust from around the hearth. Gently wrap this ‘baby’ in its downy tinder and blow gently to help oxygen reach it. Your breathe will cool it so keep at least 15 cm away and be gentle, watching at all times.
Holding the tinder nest in both hands lift it to head height and surround it with the edges of tinder – try not to let heat out. Raising it like this helps the heat to reach the tinder and heat it, helps air move and protects you face. Again, don’t hurry or blow too hard. Slowly the tinder will get hot and begin to smoke also. Keep a careful eye on the glowing ember and be prepared to close the tinder in on the ember if an air gap forms – you must keep the fine tinder close to the heat but avoid too much space (hence using very fine tinder closest to the ember). Add more tinder if necessary and also take care not to burn your hands or get sparks in your face.
The tinder nest will now resemble a smoking ball between your hands! Keep blowing into its heart and watching both the smoke and the glow. It will become more intense and you can blow more strongly, until it bursts into flame! You may need to give it one or two more puffs before it burns freely. Success!
Now place this flaming tinder into the pre-made kindling and treat as kindly as you did the ember!
More about your materials
Types of Tinder:
Rosebay Willow Herb down
Cramp ball fungus, Daldinia concentrica
Horse’s hoof fungus, Fomes fomentarius (with saltpetre = amadou)
Wood punk, crumbled
Dry grass leaves
Thin outer bark: birch, clematis, honeysuckle, cedar, willow herb, juniper
Inner bark: cedar bark shavings, lime, oak, chestnut
“thinner than paper” fine like hair
Tinder kept in a tobacco tin / shoe polish etc
Fluff or down
Old man’s beard
Birch, Cedar, Spruce Bark – Hair or powder
Dried lichen, moss and grasses – Buffed and thin
Charred cloth (cotton or silk)
Bird down (from inside nest)
Dried Evergreen Pine Needles
Fine Wood Shavings
Pulverised Fir Cones
Squeaking – You need to apply more downward pressure, increasing friction. Wood may be too damp, needing gentle bowing to gradually heat and drive off moisture before increasing friction to create dust. There is no point drilling a hole and not creating the dust!
Glazing – This causes insufficient friction as the surfaces have become polished. Scrape off glaze or roughen to make a more abrasive wood surface of both tip and hearth.
Common problems include wet tinder and kindling, not enough air for burning, too much air space allowing cooling of the fuel, too large a fuel size, insufficient fuel readily to hand, and giving up too soon.
Moisture (water) will help transmit heat away from the fuel thus drastically reducing the chances of success. The fuel must be very dry.
Too large a fuel size will likewise take far too much heat to reach combustion and will not allow air to the fuel. The surface area of the fuel must therefore be great by being as fine as possible, getting progressively thicker as the air is pre-heated by the fuel. It is for this reason that as the fire becomes more established (hotter) with a good base of wood embers, the size of fuel burnt can increase considerably, and even wet wood can be burnt (there being sufficient additional heat to compensate for heat lost through evaporation (steam).
Keep friction minimal at top (non-working end) of spindle with hand block. Use a lubricant and keep the tip more pointed to reduce contact surface area. Pay attention if this is the cause of squeaking – not the working end.
Keep lubricant away from the working end of spindle and hearth at all costs!
Take care to avoid injury from the spindle slipping out of hearth or hand block. Good posture is essential, and don’t rush.
For more advice and courses visit the Five Senses website or buy a fire kit and start playing.