Have you seen this video on youtube? A guy that uses a bow drill to make fire and it literally explodes in flames? How is that possible? Anyone experienced this before?
No, i have not seen that, but a few crumbled match heads could produce that effect, pretty easily. Do you have a link or the youtube ID?
I found one video titled with the word explosion, but is was hype. Just tinder flaring up in the usual manner. Saw another about a home-made fuel cube "exploding", but all it did was break a small glass dish that it was burning in.
Short answer is that it is not possible. The friction barely produces enough heat to form an ember, which is part of why so many attempts fail. There is no way a **traditional** bow drill could explode into flames. That being said, there are many "manmade" (purified, concentrated, synthesized, etc by non primitive means) substances that can be added that would flare up in the slight heat of a bow drill. Here is one vid that popped to mind upon reading the header and OP: Note that with the first method (potassium permanganate and sugar) he did not need nearly the heat and pressure of a bow drill to achieve ignition. Off topic, however if you watch the whole video pay special attention to the burn characteristics of PURE magnesium. Vastly different than the magnesium ALLOY in most "magnesium fire starters" these days. Pure magnesium can be useful when starting fires in difficult conditions or with suboptimal materials. Magnesium alloy is the worst way to start a fire that I have ever seen. Anyhow, not sure which vid you are referring to. Knowing that would help in analyzing it.
This has me wondering what the effect would be using a different wood for the fire board, like one of those Punk wood fire starters
Some fungi work well as hearthboards. They are softer and more punky (texture and burn characteristics) than most hearthboard materials. The better woods for Friction Fire are slightly punky. (Think fingernail test.) The punks you mentioned will be too soft to use as the hearthboard on their own, yet may allow achieving an ember more quickly and easily a la Pete's use of PP and sugar in the vid above. Certainly an interesting line of inquiry.
Thanks Kylegap for the link and the fun thread! He obviously added an accelerant. Looks like gunpowder, yet could be a number of substances. Note that he already had an ember before adding the "paper". Further proof that this is a party trick. Which could still be useful in a desperate situation, mind you. To me there is no such thing as cheating when accomplishing a task. At least when one is not involved in a contest with rules anyhow. In the description he seems to be implying that he is using primitive methods and materials and that it was a strip of paper birch bark. The former seems extremely unlikely to me, the latter is indeterminate. Looked more like wood pulp paper (aka normal paper) than birch bark to me, but it is tough to say from that vid. Birch resin has never shown any signs of behaving like that in my decades of using it for many tasks. Paper however can be soaked in a solution (often water) with potassium nitrate, gunpowder, blackpowder or other such accelerant, then dried. Often called "Touch Paper" at that point. They cut away, so anything could have been added during the gap(s). He does state that he will reveal more at a later date... ;-)
