From: ahahma@polaris.utu.fi (Arno Hahma)
Newsgroups: rec.pyrotechnics
Subject: Re: Questions on Blasting Caps
Message-ID: <1991Jul19.152817.25955@polaris.utu.fi>
Date: 19 Jul 91 15:28:17 GMT

In article <sg7551w164w@sys6626.bison.mb.ca> rcgenius@sys6626.bison.mb.ca (Clayton Grassick) writes:

>Does anyone know the specs. on how to use Hexamethelenediammine peroxide
>(HMTD) as an initiator ? I know that it is WAY more powerful than MErcury
>Fulminate or even Lead Azide and it is dead simple to make, but not

Just like any other initial detonating agent. Fill a cap with it and
press the charge. For a more reliable cap use some secondary high
explosive as a base charge, i.e. press the high explosive into the
cap and then a little of the initiator on it. This is also a safer
method.

Note, that caps frequently explode while being manufactured in the
industry. The explosives industry has very strict safety standards.
Still, the cap presses blow up about once a month. The tools and dies
are not cheap (often made of hard metal or metal carbides) so this all
adds to the price of commercial caps.

>exceptionally hazardous... How much is needed to simulate a #8
cap,can

HMTD is exceptionally hazardous to press, it explodes, if pressed too
hard - I have personal experience about this. Too hard is really not
hard at all, no machines are allowed! Pressing by hand (with proper
safety precautions) is OK - not a single explosion after abandoning
machinery. Also, the cap should never be made of metals other than
aluminum, since HMTD is totally incompatible with most metals. If the
cap does not explode during manufacture then it will deteriorate in a
few hours/days due to the catalytic action of the metal. Copper and
its alloys are particularly efficient in this respect.

>Acetone peroxide be used, must I contain it in metal, ect....

Acetone peroxide is not strong enough, it can ignite only very
sensitive compounds. It can be boosted like mercury fulminate by
mixing it with potassium chlorate. However, this makes the pressing of
the caps hazardous, since the chlorate particles cause friction.
Acetone peroxide is sensitive to friction. Moreover, acetone peroxide
is about as volatile as acetone itself, it sublimes at 56 oC. If it
doesn't escape from the caps it recrystallizes on the surfaces of the
container or the cap. These crystals are beautiful long, crystal clear
needles. As with lead azide, large crystals are sensitive and explode
if touched too hard, like with a fuse introduced into the cap.

>In short how do I make a (preferrably) shrapnel-free cap ?

There is only one way: make the casing out of a non-fragmenting
material. There is just one problem to this - where to find this kind
of a material? The cap should also be mechanically strong to prevent
the explosive from cracking, falling out etc. in the use. Also, it
should be possible to squeeze the cap to the fuse tightly, like you do
with the metal caps. I always set high demands on reliability and low
cost. This is why the possible materials for building, for example
blasting caps, are fairly limited.

>(Clayton Grassick) a user of sys6626, running waffle 1.64 >E-mail:

ArNO
    2

From: ahahma@polaris.utu.fi (Arno Hahma)
Newsgroups: rec.pyrotechnics
Subject: Re: Questions on Blasting Caps
Message-ID: <1991Jul19.170546.28072@polaris.utu.fi>
Date: 19 Jul 91 17:05:46 GMT

In article <sg7551w164w@sys6626.bison.mb.ca> rcgenius@sys6626.bison.mb.ca (Clayton Grassick) writes:

> How much is needed to simulate a #8 cap, can

Sorry, I forgot to answer this last time..

"to simulate"?? Using HMTD is really not a simulation at all, it is a
powerful explosive, which makes at least as efficient caps as the
commercially used explosives do. For a #8 cap (as defined) you need 2
grams of mercury fulminate or a corresponding amount of another
explosive. Since HMTD is more powerful and possesses outstanding
initiating properties, you need less than a gram. I'd estimate 0,8 to
1,2 grams should be enough, if used alone, with no base charge.

>--- (Clayton Grassick) a user of sys6626, running waffle 1.64

ArNO
    2

From: ahahma@polaris.utu.fi (Arno Hahma)
Newsgroups: rec.pyrotechnics
Subject: Re: Cherries and crackers...
Message-ID: <1991Jul22.143046.29232@polaris.utu.fi>
Date: 22 Jul 91 14:30:46 GMT

In article <os3c61w164w@sys6626.bison.mb.ca> rcgenius@sys6626.bison.mb.ca (Clayton Grassick) writes:

>Why do we need to compress a detonator like HMTD ?

To get as high a detonation pressure as possible. The detonation
pressure is proportional to rho*v^2, v = detonation velocity, rho =
density of the explosive. So, to get an intense detonation front, the
explosive should be as dense as possible.

>I read that TACC (tetrammine copper chlorate) doesn't need to be
>compressed !

Neither does HMTD, it surely detonates as a loose powder. But if you
are going to initiate something, then you will have to press it.

>--- (Clayton Grassick) a user of sys6626, running waffle 1.64

ArNO
    2

From: ahahma@polaris.utu.fi (Arno Hahma)
Newsgroups: rec.pyrotechnics
Subject: Re: HMDT
Message-ID: <1992Mar13.111633.25956@polaris.utu.fi>
Date: 13 Mar 92 11:16:33 GMT

In article <RL103465.92Mar10065320@korppi.cs.tut.fi> rl103465@cs.tut.fi (Rauli Lauhanen OH1MKS) writes:

>I get that recipe from some place, and was eager to try it. Of course
>every self-respecting chemist have all the chemicals in hand

Of course ,-).

>only 1/5 full .22 cartridge of Pure HMTD only was enought to detonate
>Trotyl. I didn't even use any booster explosive, just a minimum amount

HMTD is more efficient as a primary explosive than lead azide, as your
example shows. With lead azide, detonating TNT is not easy.

>  Well, I put a small piece of HMTD into a brick, and hitted it with a
>hammer, and it didn't detonate. I also tried a 'spark-test' from a

In fact, HMTD is more shock sensitive than lead azide. I think you did
missed the sample with the hammer. Hitting it would have caused it to
detonate. A "standard" hammer test is done with two hammers, placing
the sample on other and hitting them together. That way it is easier
to hit the sample with the first try.

This is a really powerful test, if you suspect a compound to be an
explosive. If no crack is heard, the smell will tell you about a
reaction. Note: use very small amounts, less than 10 mg. Even that
much will scare you enough in case of a fully positive result.

>normal condition, HMTD wont detonate If you light it, It'll burn like
>cellulose nitrate - with a yellow flame,

but much faster.

>Happy to see, That I'd found A PERFECT Primary-explosive to detonate
>high-explosives.

I didn't, that is why I made some further testing before full scale use.

>  Well At the July of 1989 It happened, I was damping HMTD into a .22
>LR copper cartridge, with a standart match, you see holding that
>cartridge in my left hand ,when it suddendly detonated, A HUGE explosion,
>and I found that for some reason, my hand was bleeding abt 1/2 liter
>of blood per min ( 1/9 gallon per min ) , and I could see my bone
>'shining' through scraped human tissue.

Ouuch! That sounds bad! I was more lucky due to some precautions. The
accident you describe is almost exactly the same I had with HMTD - in
fact it was the only accident I have ever had with explosives. I
was also making a test cap into a .22 cal casing, using a press. But,
as usual, I used shields made of 1,6 mm thick stainless steel around
the tools. Additionally, I have a habit of using double shielding to
protect my eyes.

The cap blew up, when I applied slightest pressure on the ram. I had
underestimated the power of the explosion - the fragments of the cal
.22 cartridge penetrated through the stainless steel shields, through
my right hand and into my both legs. There were only about 250 mg of
explosives in the casing, 50 mg of HMTD and a base charge of 200 mg
beta-HMX.

This time, the habit of using additional shields as an eye protection
most probably makes it possible, that I am now reading these articles
- safety goggles were a psychological support only. Moreover, the
fragments ripped off more material out of the shields (which looked
like sieves) making the net result even worse.  Fortunately, the
fragments were very small and did not penetrate deep into my legs - I
was able to pick them off. My hand is also fully operational and without
scars, although my thumb still contains lots of stainless steel and
brass dust (maybe hundreds of tiny particles on an X-ray photo).

>   Epiloque. Never NEVER load B-caps in your hand, Always use special
>tamping device when loading Blasting caps - any other use for HMTD is

That shoud be self-evident to anyone! As a hint of the dangers, the
industry has to replace the tools every two month (in average),
because of accidental explosions.

>detonate, and now, when I try to load that stuff from same batch into
>a copper container, It detonates, even I press with maybe 1/2 kg

The reason is: almost all metals greatly enhance the decomposition of
peroxides. HMTD is actually incompatible with all but the noble
metals. Aluminum does not sensitize HMTD, but is corroded by it over
prolonged storage. I have several years old HMTD caps made into
aluminum casings. They are fully operational, but the casing is badly
corroded.  Copper and brass are also corroded, much worse than
aluminum. The HMTD is destroyded within hours, if loaded into a copper
or copper containing casing. That fast a decomposition may well cause
a self-ignition simply due to heating.

Aluminum is also the tank material for hydrogen peroxide. It has to be
very pure to fit that purpose, any other metallic impurities may cause
an explosive decomposition of the peroxide.

In addition to being sensitive to metals, HMTD is sensitive to
pressure. I also made tests in plastic and glass casings. Pressing the
cap leads to an explosion in all cases, with glass, aluminum and
plastic casings you just have to apply more pressure than with
metallic containers. Still, the required pressure is far less than
applied for loading caps.

>   Maybe the batch was impure, but believe me, It really explode
>without no reason. I must say that HMTD is a good explosive, but It's

The impurity most likely came from the casing material. There is
another possibility, too. The HMTD has to be microcrystalline. Any
visible crystals will sensitize it, just like lead azide, not as bad,
though. Pressing coarse material is very risky.

>truly unpredictable. I'm sure that there are many others in this
>newsgroup who can tell the same thing - months of hard handling, and
>then, a explosion by a minumum force.

I have not found HMTD unpredictable. It is just incompatible with a
great number of usual materials - that is why it may seem to behave
unpredictably. HMTD is an excellent example of the importance of
the compatibility problem. Not alone the explosive determines, if
it is useful, the contact materials also have an influence.

>   Use trotyl, and blasting cap instead.

That is a good piece of advice. If you need an explosive only to do
something with it, not to research it, why take the risk of using
primary explosives? Secondary ones are much safer.

> HMTD will lose it's potent among time. I found that older stuff than 4
>months was too cheesy to use.

In that case, your product has to be impure. It does decompose slowly,
but it will remain functional for at least as long as mercury
fulminate, i.e. a couple of years.

>>   ends smashed shut with a vice and a long cannon fuse stuck out the end.
>>   Light it, and get the hell away!

> Holy shit, That's silly , believe Me. You can fuck with Mercury
> I WAS LUCKY

That is silly, indeed! With a plastic pipe it is there and there, but
with a metallic, possibly rusty inside... Pipe bombs of HMTD - you
have been even luckier!

>>      Word,
>>	MM

>Rauli Lauhanen rl103465@cs.tut.fi * 50.000 men were sent, to do the will of

ArNO
    2