First off I would like to point out that I have searched but found no solid threads dedicated to the synthesis of HMTD, so that will be the focus of this thread. Also, I am not responsible for anything you do using the information I provide if you are not intelligent enough to handle explosives properly you deserve anything you get. HMTD, AP, and any other primaries should never be used as a main charge, there are many easy to make secondary explosives that are much safer and powerful. Before you think about making large amounts you should ask yourself *is making this amount of extremely sensitive explosive for a quick bang worth risking my life for?* If yes than you need to find another hobby.
Over the years I have looked over many primaries to use but have only considered 3 which were HMTD, Lead Styphnate, And DDNP. Unfortunatly for many the materials needed for Lead Styphnate and DDNP are hard to make and/or buy. However instead of resorting to AP there is always HMTD, just as easy to make as AP and much better in my opinion. I have collected much information in the past months about HMTD and have found many interesting things, for one it is less volatile than AP meaning HMTD can be stored rather safely without loss of performance or increased sensitivity. HMTD was even at one point considered for commercial use in blasting caps but it was a little to sensitive to produce for such use, however for us that is something that can be overcome with safe handling procedures and proper preparation of the explosive itself. Also the only drawback of HMTD is it's reactivity with metals, it reacts dangerously with all metals and may explode. There is no need for metal blasting caps anyway unless you like shrapnell being thrown at you.
Before I move on to the synthesis I will present some figures about some properties of HMTD and the velocity of detonation.
The molecular formula of HMTD is C6H12N2O6. The vdet is
4511 M/sec. @ 0.88 G/cc and 5100 M/sec. @ 1.10 G/cc. Compared to AP which is only 3750 M/sec @ 0.92 G/cc and 5300 M/sec @ 1.18 G/cc. At first it may seem that AP is more powerful but as you can see AP requires to be pressed quite more than HMTD to achieve it's max v.det which is extremely dangerous to attempt without proper equipment. Meaning slightly pressed HMTD will be more powerful than slightly pressed AP.
Being a peroxide it is still very sensitive (as most peroxides), but not on the same level as AP. This isn't to say HMTD is a wonderful perfect primary, it is still very sensitive and if you don't respect it you will pay dearly for your ignorance. Also another thing NEVER MAKE PUTTY EXPLOSIVES WITH HMTD! This includes any nitrocellulose based things such as smokeless powder. If you attempt this the HMTD will almost certainly detonate as the putty hardens. And in conclusion I warn anyone to never make more than 60g of this exposive, the same goes for AP which is even less forgiving.
Now that you have an idea of the power and sensitivity of HMTD we will move on to the synthesis. There is one mainly used synthesis for HMTD which uses citric acid, I personally suggest using HCl which is cheaper than citric and the HCl will evaporate as the HMTD dries.
First here is the synthesis for HMTD using citric acid. You can subsitute with any other concentration of hydrogen peroxide, such as if you are using 3% just add ten times as much to account for all the extra water. However lower concentration peroxide seems to produce worse yields than higher concentration. This synthesis is compiled mostly from my own experiences and what I have read, along with the synthesis from roguesci which I tweaked.
First measure out 50ml of 30% H2O2 and put it in the freezer until it's tempeature is at 0c to help keep the reaction cool. Next prepare an ice bath and set the beaker in it. Now you will need 14g of hexamine which can be purchased cheaply online or from buying hexamine fuel tablets at camping stores. Slowly add the hexamine to the H2O2 and keep it below 10c or preferably at or under 5c. It will take some stirring and such to dissolve all the hexamine but be patient.
Once this has mostly dissolved measure out 21g of powdered citric acid. You can begin adding the acid slowly and keep the temperature below 10c or you risk yield loss and possibly a runaway. Once this has been added stirr for a few minutes and place in a freezer if availible or keep it in a ice bath for 3 hours. You may or may not see crystals forming, either way move the solution into a refrigerator or a cool water bath for around 2 hours (I put mine in the refrigerator over night for better yields). You should see a white precipitate and this is HMTD. Filter the solution and wash with water until you are sure it's neutral (very important!) you should also wash with a bicarb solution.
The yield will vary depending on what concentration the H2O2 is, how low the temperture was kept during the reaction, and how long you leave it in the freezer and refrigerator. Normally you will get good yields when using 30% H2O2.
Next is the synthesis using HCl (what I use).
The synthesis is exactly the same as the one using citric acid exept you would use 20g of Hexamine, 60ml of 30% H2O2, and 35ml of ~30% HCl. If your HCl is ~20% concentration you should use about 45ml to ensure complete reaction.
Here is a picture of what mine looks like after sitting overnight in the refrigerator (I used the exact same synthesis as described above):
I hope you have found this informative and useful, it took alot of time to write all this and research everything. I will soon have a video up demonstrating the properties of HMTD and maybe even a small detonation video. If there is any confusion or questions about the synthesis and such please feel free to ask me about it.
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Synthesis of HMTD 
Linear Mode
