Processing Hexamine

[Bonny]

I couldn't find any info here on how to powder and maybe purify hexamine from stove tablets. I remember reading somewhere that the campfire stuff is not pure. The solubility in water is high, so maybe dissolve and filter to clean it?

Can it be coffee milled or will I end up with a mess caked in the grinder? I was thinking of freezing before milling might help as it does wonders with shellac flakes.

[mikkello]

Dissolve in acetone, filter and let it evaporate.

Easy

[Ralph]

I have been told that the primary impurity is paraffin wax which is insoluble in water so divide it as finely as posible and add to hot water (will melt the wax making more of the hexamine disolve) filter it than evaporate off the water and you should be ready to roll

[al93535]

I used to use the esbit tablets myself.

 

Crush the tablets in a bag, as fine as possible to speed the dissolving process. Boil some DISTILLED water. I forgot how much hexamine is dissolved by how much water. But you want to add the powdered tablets and stir until it all dissolves.

 

Filter the solution. Discard what is caught on the filter. Pour the solution in a big shallow baking pan (glass preferably). Put it in the oven at 250 degrees. (This stuff will smell god awful!! Like bad fish!!!) Stir it often as a film will develop over the top and prevent fast evaporation.

[quicksilver]

Your query is an interesting one from a certain standpoint: I once priced what it would take to make hexamine (formaldehyde + ammonia) ending with a reagent grade product.

IF one can obtain a good price on the formaldehyde (one price of $12 per L at store catering to ponds w/ fish), it really makes sense to synthesis your own as then you know that other "crap" doesn't exist therein.

Let's say you buy heat tabs, looking at the price: it makes stars, etc extremely high expensive. The components for an ammonia generator costing VERY little (bottle, stopper, hose, ammonium sulfate fertilizer or other source & lye) approx 10-15 dollars. Yield with formaldehyde (37%) and pure anhydrous ammonia could be 1/2 what retail powdered hexamine would cost, let alone heat tabs. Then once you're set up the cost would drop from there.

I think it's a great idea to make whatever one can whether it be charcoal, nitrates, sulfur, chlorate, powdered Al or Mg, perchlorate, or Hexamine!

Edited February 8, 2010 by quicksilver