HMTD making

[209]

Let me warn you, this is a very "water cooler" post.

My parents are home from the States now so my making of explosive peroxides that require the fridge have come to an abrupt halt. I need to make a bit more HMTD tomorow but cannot use the fridge, after all the reactants have been mixed and it need to be kept cool, woud I be able to leave it in a bucket of cool water outside? It is Febuary now, but hasn't been down to zero for several nights now. If I can leave it outside, can I leave it in the garage? (it still stays pretty cool).

Thanks

[Shalashaska]

Check the temperature outside and apply it to the situation. If I were you, (depending on the vessel it's in), I'd hide it either in or behind something in the freezer. If you have and cylindrical ice cream containers, that might work.
I may also suggest watching yard and garage sales in the future for a small meat freezer, and keeping it in your room to keep your "soda" nice and cool.

[mike16]

When I make AP, I put it in the freezer for a couple of hours.

Also cover the top of the vessel with some pastic sheet and elastic bands, so nothing can contaminate it.

When I do this, I leave the mix in the freezer for about 2 hours, and when I take it out, I have a solid mass of AP crystals.

[Horrigan]

If it was me, I'd dissolve fertilizer-grade AN to get cold temperatures and then filter and recrystallise to get purified AN.
4€ 5kg 33,5%N AN bag :D France has good side... ;)

[Alexires]

From a subjective point of view, I would say HELL NO. HMTD is dangerous normally, without the added danger of some kind of runaway reaction/more sensitive composition/etc. If you want to keep your fingers, buy a bar fridge.

If you are willing to stay up all night, then you could try an ice/salt bath which you replenish when it gets low.

Objectively, I can't see a problem with it really. More heat=faster reaction (I believe) so sure, you probably could just leave it in the garage. Take precautions in the case of a premature det, or runaway reaction.

You should take into consideration how far off 0 your nights get. If they go down to 2 or 3 I'd say sure, go for it. You might be able to get away with 10*C, but you might want to think about using an ice/bath in a sealed polystyrene to inhibit heat gain as much as possible.

209, remember what happened to phone. Don't play around with this shit, you probably don't NEED to have HMTD tomorrow, just WANT it. Don't let that cloud your preservation instincts.

[209]

I left it in the icebath outside and cam down this morning to find...... Dick happened! No crystals in the beaker, no nothing, what the hell happened? Should I put the beaker in a warm water bath?

By the way, yes,I do remember Phone, to make that much AP he had to be a real dumbass.

[Chopper]

I left it in the icebath outside and cam down this morning to find...... Dick happened! No crystals in the beaker, no nothing, what the hell happened? Should I put the beaker in a warm water bath?

By the way, yes,I do remember Phone, to make that much AP he had to be a real dumbass.

:eek:
Warm water bath? No freaking way man. Sure you didn't know him personally?:p

The method I've always used successfully involves about 3kg of ice-cubes, a 4 liter ice-cream tub and a 500ml/1L pyrex kitchen jug.

I start the synth at around 4pm, pouring the h2o2 straight from the freezer into the jug, also straight from the freezer. Everything is mixed together in the pyrex while it's sitting in the bucket surrounded by about 2kg of ice-cubes a tablespoon or 3 of salt and the minimum water required to come up the side of the jug as far as the solution inside it does.

At around 9-10pm I go back and check it - it looks like nothing has happened, except the ice has melted. I replenish the ice and go to bed. In the morning, there's often a fair-bit of precipitate, though the mixture is still rather thin.

After pouring a small amount (~50ml) of the mix into a jam jar, I leave it sit for another 4-5 hours at room temp. Over this time, the jam-jar mixture becomes incredibly thick while the one in the cooled pyrex doesn't change too much. After acertaining that the reaction has proceeded far enough with cooling, and that the jam-jar mix has finished reacting uneventfully, the pyrex is removed from the water-bath and allowed to sit for 4-5 hours or more.

Stirring during this time of sitting uncooled GREATLY increases the yield. Using this method I have made upto 70g dried hmtd in a single go. Hence the seperation into batches for the 'warming' stage. Just start super-small and ALWAYS use a much bigger vessel (wide as possible for maximal cooling effect) and a lot more ice than you think you'll need. It's seriously unpleasant when the reaction gets too hot and starts to run-away. I've not had a serious problem during the 3 run-aways I've had. But I'm not about to try my luck again...

Just use lots'n'lots of cooling and an equal measure of patience and brains.
When done properly, the stuff has a shelf-life in excess of 12 months. Neutralzing with a base, as opposed to repeated rinsing with fresh water and decanting seriously kills the shelf life (and presumably, the already dubious safety margin associated with the organic peroxide compounds)

You really shouldn't make the stuff whenever possible - this is just the method I have employed succesfully in the past.

Also, for what it's worth - I use 50% h2o2, calculate how much water is needed to dilute it down to 30%, then mix that amount of water with the citric. This greatly reduces the time needed to get eveything dissolved. It also reduces the chance of runaway that would be present if just using undiluted 50%...

[209]

Yeah well..... Yesterday was when I started the synth and I added all the reactants and nothing really happend. It didnt heat up in the least and no crystals have formed since yesterday, I am beginning to wonder if my chems are no good? Hydrogen peroxide 3% crap, citric acid (grocery store) and hexamine fuel tablets (sporting store) the back of the package says "these tablets are made of hexamine a clean burning.........blah blah blah (the tablets didnt have any wax in them)

I added the reactants: (my scale is a piece of shit)

Hexamine (approx. 10 grams)
Citric (approx. 18-20 grams)
H2O2 300mL

Are the ratios wrong?

[Chopper]

Hmm, I don't have a recipe anymore & can't be bothered looking BUT from memory everything is about right except for all that water..

If my crappy memory serves me correctly, it's (the reaction rate) dependant upon pH and temp. The endpoint (or amount of product you get) is also strongly affected by concentrations. More strongly concentrated solutions will react both faster and more completely. They'll also get hotter during that time.

Before I managed to find the H2O2 at a hydroponics store, I also used the 3% shit from the supermarket. When using that stuff, I found it highly advantageous to put it in a ceramic (stoneware) saucepan and heat _very slowly_. I would typically reduce a 200ml bottle of 3% to about 50mls in around an hour or so. After I'd done that to a number of bottles, I would combine them all - knowing that I now had 50ml per bottle instead of 200, I guestimated it to be _around_ 12% - can't be sure since some of it's bound to decompose in this time.

After I had around 150ml of this more concentrated stuff I would then evaporate that down to around 50mls again. This would give me a solution that could not possibly be more that 36% or so. But again, it would not be this strong due to decomposition.

Now it's important that I state, the reason for doing a number of bottles and for doing them in two stages is to reduce the effort needed to avoid decomposition. In only doing one bottle at a time, you'd have to evap 300ml down to around 30ml. When you're getting near to the end of the job, you've got a gas flame heating a huge-ass sauce pan with only 30mls of liquid in it. It's rather difficult to carefully control the rate of evaporation with so little liquid. This is why it was done in two stages. Although I could have just dumped a few bottles in together and then evap'd that down to the calculated amount, the temptation is to crank the heat up too much at the start and waste some of the H2O2 through over heating. At least with a couple of small runs, I could see the progress the whole time.


If all this seems like too much of a pain in the ass, even using a stainless steel saucepan and evap'ing down to even 1/2 or 1/3 of the volume supplied me with better results. I just made sure I used what I thought would be a 25% excess of this evap'd h2o2 to account for any lost during the heating process. Besides, when I was doing it, h2o2 was easier and cheaper to get than hexamine.


But to answer your question - yeah, the ratios look about right. It's just the water. From memory, 1g hexamine needs 1g (pure) h2o2 - adjust for concentration. Each 1g hexamine needs 1.5g citric acid. So, it's 1:1:1.5 - Hex, h2o2, citric. Assuming the h2o2 is 30%. Stronger peroxide is said not to provide any advantage over 30%, from memory the pH doesn't change all that much as the percentage gets higher once its above 30%. Weaker throws the reaction out..

[209]

Thanks Chopper! I am going to try your method for H2O2, I was always under the impression that you couldnt boil hyrogen peroxide because it would all decompose leaving you screwed. One last thing, I know that somehousehold cleaners contain large amounts of hydrogen peroxide ( 25% and up) does anyone know of a name brand cleaner that I can use for hydrogen peroxide?

thanks

[tiac03]

Go to the Pharmacy and go into the hair dye section. They usually have a 9% hydrogen peroxide bottle there (30 volumes). Should help a bit (and if worse comes to worse, less to boil down).

[Alexires]

209 - I believe it has been talked about somewhere on The Forum regarding how concentration effects the product. IIRC, it is an exponential, not a linear function, hence 3% H2O2 will be 4 times slower than 6% in the same conditions. So there would be a HUGE difference between 30% and 3% (somewhere in the order of 100 times slower reaction).

It is definately worth boiling your H2O2 to get a higher %. Try to keep the temperature below 78*C from memory. Remember, more surface area and the more air moving past the surface will dramatically increase your evaporation.

If you get your previous attempt at HMTD and let it warm up, see if crystal precipitate. If they do, you know your doing it right (I would probably disregard those crystals though, incase they are unstable). If nothing happens, then you know it isn't your method, it's your reactants.

Remember, if it works for everyone else, but not you, you've fucked up somewhere.

[209]

I've searched the hell out of the forum and google with still no resolution to my problem. I boiled down my 3% hydrogen peroxide from 1000mL to 100mL hoping it would make a difference, I added the reactants..................morning later, Nothing.

Hexamine 8 grams
citric acid 14 grams
H2O2 -30mL

heaxamine from the full tablets (I think it was pretty much pure hexamine)
citric acid - grocery

whats wrong here, any ideas?

[nbk2000]

What was the cooling?

[209]

this forum is the best! I read a post on how some guys makes his ice bath and I tried that method, I just checked the fridge 5 minutes ago and there is a solid mass of HMTD crystals in there!!! YES! Thanks again for your help.