Micro embers from rubbing wood together - which woods will form them?

[rich59]

I was practicing the bamboo fire saw when I noticed something interesting. (It isn't very physically hard by the way.) When rubbing a (nearly) flat piece of big bamboo along a sharpish bamboo edge one can fairly quickly get to a point when there is smoke coming from the wood. Then it gets more interesting, little smoking bits fall from the sharp edge, and carry on smoking for a few seconds before going out. I think these are micro coals/ embers. I think the finer points of the full method to make fire gather such micro embers together to make a sustained fire.

So, I was thinking. If one could find the same phenomenon with other woods or wood combinations then they too would probably be usable in fire saw like setup to make a fire.

So, that's were I could do with your help. Have you seen this phenomenon with any woods. Have you got some wood types around you that you could try?

I have tried with large bamboo (success), elder, sycamore, pine (pallet wood). No joy so far. Each wood makes a different sort of wood fibre/ dust. Bamboo's product is brown, quite fluffy with splinters in, occasionally one is smoking for a few seconds. Elder makes a dark dust. Sycamore makes lots of dark short splinters. Commercial pine made a brown coarse dust.

 

[Toddy]

Interesting and I'd like to hear how it goes with this

I was using an ivy hearthboard at the weekend, and the fibres from it are pretty coarse sometimes. This piece came from a bit that was as thick as my forearm. I have more if you would like to try it ?
I get a brown fibrous but not hot coal from it very quickly, but if I keep going the heat builds up and it all slowly goes black; but sometimes the fluffy stuff falls off the board in a clump and it's already glowing when it does. It needs to be past that first brown stuff is what I'm trying (and probably failing) to explain.

cheers,
Toddy

 

[forrestdweller]

LLOOONNGGG time ago i experimented with poplar in this direction (works well for me as bow drill) - using one half of a split piece as the saw and the other half as base-but i did not get beyond smoke and dark brown dust (problem is getting enough speed/pressure on your own- aborigines usually use(d) fire saws as two-man- ""operations"" ).... . once the rain has stopped i might go and fetch some from a nearby source and give it another try with a ""split-stick"" base... .