I probably make more fires with fatwood than anyone on this forum ( Ok except Bushman ) and it's still hit or miss.
On a nice sunny, dry day with thin fatwood shaving I place the end of my ferro rod onto the tinder and give maybe one or at most two strikes and I have fire...nice !
But for whatever reason, poor weather, poor tinder or maybe even sods law cos I'm trying to show a mate it goes like this:
Strike,Strike,Strike...." $ollocks !....."Strike, Strike...see fire but as fast as it starts it goes out again in a whisp of black smoke "$olloks !".......Strike,Strike,Strike"$ollocks!"...Strike,Strike,Strike...Nudges tinder and knocks it all over floor " $ollocks!"......Strike,Strike,Strike..Fire at last, big smile on face as I reach round for my tinder bundle....realise that Snicker has made off with it " $ollocks !!!!!!!".