The tinder and kindling would catch before the larger pieces. I take Trioxane when I got camping and when I've had trouble getting a fire going it was able to do the job. It probably wouldn't even take an entire bar - I've never needed a whole one. OTOH - I use it alone to cook (well - if you consider boiling water cooking) and depending on the temperature and whether you/'re using a windscreen - it may take more than one bar to boil water. Overall, as long as you keep in mind the toxicity, it's not bad stuff. Take some outside and experiment before you decide to take it - be familer with your equipment.