Originally Posted by SPR
lol - your the chemical expert here! I thought a man if your knowledge would know what is in these devices !
Oh yeah, I see where you where headed now. I was VERY puzzled as I had been doing just that very thing at work a while back, but I had kept the "experiment" absolutely QT. I use fairly large amount of Calcium Chloride in my daily do and it's as cheap as chips. It does this lovely exothermic reaction thingy when you add water. However, empirical testing demonstrated that while you can melt the @rse out of a plastic bucket, it won't cut it on the hills. I believe the real thing uses calcium oxide.
I use a Trangia 27, pared back to the bare essentials. It isn't the lightest or fastest system, but it is bulletproof and will work in any conditions. 250ml of fuel will see me through a 36 hour hike with spare to heat that last emergency mealie & a hot chocolate
PS: Polwart is the REAL Chemical Expert!