HexJam - 3-10-2011 at 06:56
A while back I was purifying some hexamine fuel tablets; I dissolved them in water and filtered out the impurities (a white, waxy powder that
looked/smelled a bit like paraffin) and then put the liquid aside in a glass jar so that I could do the recrystallisation at a later point.
That was a few (3-4) months ago (I'm such a procrastinator!) and the other day when I went to check the jar it turns out I'd left the lid off and it
had been exposed to the atmosphere the whole time.
My question is, will this hexamine still be good or will its being in solution, combined with exposure to the elements for so long, have done
something to it? There's only 2-3g of it in the solution so it's no great loss if it has gone bad; really I just want to double check with you guys
that it's not going to blow up in my face when I heat it up due to some unforeseen decomposition product.
Thanks for all (useful) replies in advance 
ScienceSquirrel - 3-10-2011 at 07:54
Have you seen the solubility?
http://en.wikipedia.org/wiki/Hexamine
You are going to have to boil it down a lot to crystallise it.
It will not explode but I doubt that you will crystallise anything worthwhile either.
HexJam - 5-10-2011 at 02:30
Ahh, I didn't notice that! hahah Yes, I think some boiling down will be required as my 2-3g is dissolved in ~150ml water haha