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Explosion

First static test firing with hexaphenox propellant, using an empty C6 motor casing. Combustion chamber pressure was way too high which led to the explosion of the motor. Hexaphenox is a rocket fuel I have developed:)

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If that is potassium chlorate, I learned from sad experience that many of the chlorate mixtures detonate (ie runaway burn reaction), especially ones with either sulfer (including sulfides, sulfates, etc.) or red phosphorus.

Hi Dan,

Yes, it is potassium chlorate, hexamine and a catalyst (no sulfides, sulfates, sulfur or phosphorus). Hexamine is very difficult to oxidize with nitrates or chlorates. The process is complicated but I guess, the hexamine get split without the catalyst into NH3 and formalin and NH3 cools the flame. This video shows the difference of hexamine/KClO3 and hexamine/KClO3/catalyst: http://www.youtube.com/watch?v=exHEzUllNJA

Many other potassium chlorate mixtures can give violent reactions as well.  I did not mean that sulphur or phosphorus were the only ones; just that they were examples. Many fireworks makers use the slightly slower potassium perchlorate instead, as it is much safer to handle, but some formulas still need the faster oxygen release of potassium chlorate -such as in "cherry bombs" (also called maroons) or cannon crackers (also called M-80s, M-100s, M-120s, etc.)  Here in the US fireworks laws are by state, and most states have outlawed the purchase of these fireworks. Some sell a wimpy variation under the same names, but they have a greatly reduced "bang" in comparison to the original formulas. Cannon crackers are made from potassium chlorate (64) generally contain sulphur flour (24), antimony sulphide (8) and saltpetre (13, potassium nitrate), but they add a small amount (2) of sodium bicarbonate (NaHCO3) as an acid neutraliser, so it does not spontaneously combust in storage.

Another famous chlorate mixture was potassium chlorate and nitrobenzene (also called nitrobenzol). One hundred tonnes of it was used in 1885 to clear Long Island Sound of rock so larger ships could pass. It pulverised 600000 tonnes of rock and created a 30 foot tall (10 meters) tidal wave.

Hexamine (a.k.a. Hexamethylenetetramine or C6H12N4) is quite different, though. Rather than a straight benzene ring, the structure is tetrahedral with the nitrogen atoms at the four corners of the lattice. I am thinking this could be the best place to attack it to break it down.

Btw, I know you want to use the hexamine due to its higher energy release per mass (specific impulse), but if interested, I have several "black-powder-like" rocket fuel formulas, including Congreve, Hale-Hooper, British Mk VII, etc. Standard black powder is not the best formula when used as a rocket fuel. These work better for rocketry.

Oh, and you probably already know it, but the finer you pulverize the components, the faster the reaction will be. So called "pyro-grade" chemicals are ground to a fine dust, such as carbon in the lampblack form, or "sulphur flour" which is much finer than "flowers of sulphur".

 

 

As far as I know you need now an ATF explosives manufacturing license to purchase KClO3 from Skylighter etc. in USA.  You are right, I want to use the hexamine due to its high energy release per mass. Another interesting aspect of hexamine is that it's without a catalyst not easy to oxidize with potassium nitrates, chlorates or perchlorates as well as other alkali or earth alkali metal salts due to the NH3 release which cools the flame (same function as some flame retardants). This let me think if there is a way to moderate the combustion similar to liquid fuel. As the catalyst is solveable in some (burnable) liquids, it could be inserted partially into the hexamine/oxidizer mixture and then ignited.

I wouldn't doubt that they have outlawed it...  They seem to do that with anything that is "fun".

Of course they have gotten more paranoid about terrorists and such lot in recent years.  (Lucky for me, I still have some left to play with, if I get the urge...)  Actually, back years ago when I did buy some, I had to sign a paper stating what I wanted it for, since it was considered a dangerous chemical even then.

Hmmm, I just was checking online and found that not only must you have an ATF approval for Potassium Chlorate, Potassium Perchlorate AND even Potassium Nitrate but also for anything finer than flake sulphur.  There are also some strange oddities that they require approval for ----

For instance: rolled paper tubes less than 10" (25 cm) in length...  Is that crazy or what?  Here is the note from the chemical supplier:

        All of our paper tubes 10” long or shorter require an ATFE to purchase, this also

        includes the smoke canisters in the Smoke kits. We now supply longer cans in our

        smoke kits that you simply cut to length. No ATFE is required to order our smoke

        kits. Paper tubes longer than 10 inches DO NOT require an ATFE.

Obviously aimed at people manufacturing fireworks, but ...paper tubes?????  Come ON ! and only shorter ones are illegal to buy without a permit.

 

Paper tubes???

So toilet paper tubes are illegal now in USA?

As to toilet paper, I found out something there. There is a requirement that toilet paper manufacturers change their cardboard tube to different material. In the future they must use a plastic compound that is thin and brittle (to the extent that it crumbles under direct pressure.

These people are unbelieveable...!

Next thing I expect we will hear of them limiting purchase of school notebook paper and glue, since it could be used to roll paper tubes.

You have an excellent point.  Hard to tell if they even thought of that angle.  It would probably be a good place to start if I were inclined to challenge it in court.

 

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On a very different topic, I think I was trying to poison myself today. I went to the basement to see what chemicals I still hard stored down there. A container of bright orange powder was tipped over (mercury oxide). I picked it up and realised that it had no lid at all. I realised this as it all dumped from the upside down bottle.  It apparently had a metal lid on the bottle at one time, which was rusted away. Evidence: a pile of rust in the bottom of the box it was sitting upside down in.

Anyway, I did not get much on me, and went and washed immediately.  I presume someone was looking at things in the box and put it back in upside down (and that would have been several years ago with the evidence of the HgO bottle.

They did not just "look" however.  My large container of potassium chlorate was gone, as was the sulphur flour and the pyro-grade carbon dust.  Whoever got in there seems to have known what they were looking for. Interestingly enough, there was about half a kilo of potassium nitrate that was untouched, so they must have specifically wanted the chlorate.  Grrr.

Well, I guess that settles it...  have to get some more if I want to play with fireworks or rocket fuels using chlorates.  I got a clarification that we can buy one pound per year without the license.  Not very much.  (about 454 grams).

There were a couple other containers with metal lids that were gone to rust. Then I noticed a bottle of hydrochloric acid was sitting with it's stopper off. The glass-stopper was lying in the box, and the acid had not spilled, so I just re-stoppered it.  I have not tested it for strength or impurities, but since it was sitting open for who-knows-how-long, I had better test it before use.

That reminded me to check the internet for ground glass stoppers. I have a couple other containers that need them. 

Holy CRAP!  I just looked and see prices of $60, $70, even $96 USD for glass stoppers.  That is absolutely ridiculous. Not even the whole container, just the stopper.  Ok, here are a few that are more reasonable, but I would rather pay only a dollar or two (plus legitimate shipping)

EDIT: Ok, I located the stopper to the one florence flask that was missing one. The other one missing its stopper is a small brown glass reagent storage bottle with the large end of the opening measuring ~12.5 mm (exactly 1/2 inch Imperial measurement).  I may not be able to buy that one, being brown glass and all.

Ah, finally...  I found a place that does not treat glassware like a priceless antique.  This place has flasks, beakers, storage bottles (with ground glass lids as needed) for less than $10 each, average around $5 USD each depending on sizes.  Much more like what I would expect.  Now to find a place with cheap chemicals (that does not know about or agree with that ATF crap...  ha ha)

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Maybe I should apply for that ATF license. I am going to need more toilet paper.

 

Any idea what force the thrust was? This looks very interesting!

No idea because I have not measured it. First I need to find a grain which not explodes. In this case it was an end burner.