60 replies to this topic

[blasterbert]

flash powder low or high explosive..i work for a large firework company and there is a large debate weather flash powder should b classed as high or low explosive.i buy raw chemicals and mix my own.i find that the 70/30 mix works very well in fact 20grammes of this stuff will detonate in open air and at work i blow up lumps of concrete 2ft by 2ft by 3ft with just 3oz of the stuff.it might be classed as low explosive but u definatley treat it as high explosive.do anybody share my views?

[robert johnson]

Sounds like some very good flash powder that you make. After 15 years working in EOD and fully trained. I have yet to see 3oz's of flash do so much damage unless you managed to bore a very narrow bore in to the center of the concrete and insert the flash. However I can tell you that 4 units of Pentaerythrite tetranitrate [petn]will move a german bunker sideways out of it's foundation with out rupturing it.and thats 6 feet thick. Little confused as to why you should want to blow up concrete at a fire work factory? If you like blowing things up join up with An EOD unit and that should be real fun.

[Richard H]

Welcome to the forum blasterbert, 'sounds' like you going to fit in just great! hehe.

Rob, me old mucker, PETN is pentaerythritoltetranitrate

And for anyone who wants to know how to pronounce that: penta-airy-fry-tol-tetra-nitrate

[Edited on 26-5-2003 by Richard H]

[robert johnson]

Richard do you have a background with the northern Lasses? only they pronounce it as one word. The army and us deep southerners spell it correctly.Or was my former boss wrong?

[blasterbert]

hi rob i 4got to say fireworks is 1 of my jobs i also do a lot of ground work for a engineering firm that is why i blow up a lot of concrete.and yes there was a small hole in the concrete what i am trying to say is that it would take a kilo of blackpowder to do the same job.by the way i have got 16 years in as a pro in pyrotechnics and i know what im on about.i envy u for being in the eod but in my early days i was trained by my uncle who was in the e o d.i think u are very brave for doing the work u did but u are not the only 1 who knows about explosives.beleve me 3oz of good flash will shatter lumps of concrete like that.

[Richard H]

Originally posted by robert johnson
Richard do you have a background with the northern Lasses?  only they pronounce it as one word. The army and us deep southerners  spell it correctly.Or was my former boss wrong?

I can say I do Rob, whats wrong with northern lasses? Damn sight more classy than essex girls <shudder>Jade Goody the big brother pig</shudder>.

Secondly I speak as an novice-intermediate organic chemist and you did not spell it correctly, you missed off the OH alchohol group, the 'ol' bit.

Organic chemistry can be a pain in the arse at times, the naming systems are a tad confusing! I'm not even going to attempt to draw PETN with the wonder that is ASCII art.

I hope you not having a dig at us northern folk! Yorkshire men make the best pyrotechnists I'll have you know!

The Rev. Ron Lancaster of Kimbolton fame is a Huddersfield man himself.

[robert johnson]

Ah yes but he did move down south and not to far from Essex.So what does that tell you or is land to expensive up north>>...HEHE

[pyrotrev]

Land isn't, but the Northern lasses are!

[adamw]

PETN is Pentaerythrite Tertanitrate (British spelling) or Pentaerythritrol Tetranitrate (pen-ter-arth-rite-rol tetranitrate) if you are US. As for using flash powder for demolitions, I am afraid that I have to say it's bad way to do it (inefficient). There would be more 'umph' in a foot of 60gr primacord. Plus it would be safer!. It has been proven that flash powder can actually be detonated with a blasting cap, but when it burns (albeit quickly) either as an unconfined mass or in a tube it is not detonating. I'm sorry but I can't stand it when people use the word 'detonate' as a synonym for deflagrate, initiate or 'blow' (I.e. 'Stand by to blow the charge' as opposed to 'Stand by to detonate the charge' when the charge is blackpowder persay). Thats all of my quibbles out of the way. Also, this is a fireworks forum but personally I have no objection to disussing high explosives in moderation. After all, they are used in SFX and fireworks (ie a bit of primacord to scare the audience!)

[blasterbert]

hi adam 1 last word on detonate.yes flash powder does burn but in a small mass unconfined it will produse a detonation wave.yes it would be a lot better 2 use primer cord but there is a lot of red tape 2 be able to store it.but at the end of the day u get a nice bang and a bit of fun.as for petn i dont think we use that in shows we would get to many complants.ha ha at the moment we have got problems with maroon shells coz sum bright spark as classed it as 1.1 why do they always spoil our fun.

[yanhua]

I don't believe flash powder detonates unconfined in small quantities.

But would be interested in being persuaded otherwise.

Regards

Yanhua

[blasterbert]

yanhua..this is the problem flash will burn close to det speed it is to powerfull 2 b classed as low explosive but to week to b classed as high explosive.a lot of people do not realise just how potent it can be.yes it is a defrag explosive but put a loose 1lb bag of it on the floor set it off and tell me what u think.

[robert johnson]

Been their and done that several times it's called a Gaba mortar and that was disscused with Mr Brocade a few weeks ago . it produces an almighty thump but that is it.

[blasterbert]

hey rob have u tried this one.
6.7 ounces of potassium chlorate
2.7 ounces of red phosphorus
0.3 ounce of sulfer
0.3 ounce of calcium carbonate.
for those who dont know please dont make this one.this formula is used in the manufacture of gun caps so please if u dont know what you are doing dont do it.
this stuff WILL take your life.

[blasterbert]

by the way rob ive been looking around the forums and i have got to say i am very impressed with what you know about pyro.as i was told 2day dont argue with the e.o.d he he.