823 replies to this topic

[seymour]

I have no doubt that a huge number, probably a majority of metals could, if cost and storage concerns were not an issue, be used successfully in flash powder. Because of the high energy released by a (successful) flash powder, most of them would be a very standard white flash. Exceptions certainly exist, with the bluish colour given off by Zinc compositions (including flash powders) coming to mind.

Remember that the definition of "flash powder" is very broad. Technically, the Zn/S rocket fuel is a flash powder, yet it is a very different composition to what we normally think of as a flash powder.

http://www.shutterst...fur-rocket.html

[CCH Concepts]

on the question of iron turning to rust. this is what would happen when the iron is burnt. producing FeO. could there be a method somewhat like dragon eggs, where this first stage takes place and then another. my thought is if some how the iron could burn with an oxidizer producing Fe) and then the FeO react with Al to start a thermite reaction. would it be possible to separate the stages with in the reaction. one composition two reaction, like in dragons eggs.

[Potassium chlorate]

on the question of iron turning to rust. this is what would happen when the iron is burnt. producing FeO. could there be a method somewhat like dragon eggs, where this first stage takes place and then another. my thought is if some how the iron could burn with an oxidizer producing Fe) and then the FeO react with Al to start a thermite reaction. would it be possible to separate the stages with in the reaction. one composition two reaction, like in dragons eggs.

There is thermite burning almost like flash, namely thermate. Google it.

[CCH Concepts]

There is thermite burning almost like flash, namely thermite. Google it.

funny man. lol
what i was getting at was a dragon egg like comp that has a duel process.

so first it will burn producing the FeO and then this will react with the Al.


but the more i think of this the less i can see how it could be done. it would involve a method of first reacting Fe with an oxidizer without it using up the Al and once all the Fe has been totally converted to FeO before reacting with the Al. i cant see how this would be possible. would make for an interesting effect if possible.

[athelas3]

I have had great success with KNO3/Mg flash, but nothing else. Its incredibly easy to make, just weigh them out in a 50/50 ratio, dry mix them until properly mixed and its ready to go!

In true 'Chaz' style heres a small pile of my KNO3/Mg flash: HERE.


...Great stuff.

Hi chaz
I have just started cautious experiments with KNO3 / Mg flash mix. I am using small quantities - but have struck my first hurdle. I have fairly fine ground KNO3, but when I add it carefully with the MG powder and mix by folding in the corners of the paper sheet its on - I find my KNO3 cakes very quickly, despite all lumps being removed previously after grinding it in a pestle and mortar. I end up with an uneven mix - and being very conscious of the sensitivity warnings about flash comps - I don't want to gring or sieve it mechanically to remove the lumps. So - I'm wondering - how do you prepare yours to avoid this issue??

Cheers

[Creepin_pyro]

Hi chaz
I have just started cautious experiments with KNO3 / Mg flash mix. I am using small quantities - but have struck my first hurdle. I have fairly fine ground KNO3, but when I add it carefully with the MG powder and mix by folding in the corners of the paper sheet its on - I find my KNO3 cakes very quickly, despite all lumps being removed previously after grinding it in a pestle and mortar. I end up with an uneven mix - and being very conscious of the sensitivity warnings about flash comps - I don't want to gring or sieve it mechanically to remove the lumps. So - I'm wondering - how do you prepare yours to avoid this issue??

Cheers

You're quoting a post from 2004, talking to someone who hasn't been online for 2 years...

Sounds to me like your kno3 might be slightly wet, which isn't good when using it in a moisture sensetive flash comp

[athelas3]

You're quoting a post from 2004, talking to someone who hasn't been online for 2 years...

Sounds to me like your kno3 might be slightly wet, which isn't good when using it in a moisture sensetive flash comp

OK thanks - that is a good point as I know KNO3 is deliquescent, and my supplier may not have stored it in ideal conditions. As an alternative, I have tried mixing the other standard comp of Potassium Perchlorate and Al (70/30). This was much better behaved in preparation, but I suspect it might be a more sensitive mix than my KNO3 / Mg. As I have a reasonable supply of Mg and don't wish to waste it - would you suggest another comparable recipe I can use it in, that doesn't use KNO3 - and that is relatively safe as flash comps go? Thanks

[MDH]

If you are worried about the spontaneity of chlorate and perchlorate mixtures, add a carbonate in a small quantity (<3% of the composition by weight). It is a common commercial practice in china.

As I have said numerous times before as well, calcium sulfate, sulfur and german aluminum is extremely insensitive. It can be bound and granulated into a very powerful flash powder with normal alcohol and water (treated with fine boric acid to preserve the aluminum).

Calcium Sulfate is about $5 for several pounds where I live, which is a plus. I hope and assume it's as cheap in Britain.

The fine powder can be mixed in a 75 flash : 25 black powder ratio, the black powder being used to sensitize it to initiation.

Edited by MDH, 22 December 2009 - 12:24 AM.

[rr22]

[quote name='MDH' date='22 December 2009 - 12:16 AM' timestamp='1261440985' post='62525']
If you are worried about the spontaneity of chlorate and perchlorate mixtures, add a carbonate in a small quantity (<3% of the composition by weight). It is a common commercial practice in china.

As I have said numerous times before as well, calcium sulfate, sulfur and german aluminum is extremely insensitive. It can be bound and granulated into a very powerful flash powder with normal alcohol and water (treated with fine boric acid to preserve the aluminum).

Calcium Sulfate is about $5 for several pounds where I live, which is a plus. I hope and assume it's as cheap in Britain.

The fine powder can be mixed in a 75 flash : 25 black powder ratio, the black powder being used to sensitize it to initiation.
[/quot

A non sensitive flash seems in every bodies interest,I've not come across this so will check your previous.

Meanwhile,

athelas3

could dry his KN03 in the oven, just pure not compositions obviously.

[Mumbles]

KNO3 definitely isn't deliquescent.

[Potassium chlorate]

Perchlorate/aluminium/sulfur isn't really that dangerous to mix. You can watch how these guys handle it - they're licensed professionals. 4:00 and forwards.



I think we Europeans should have little more of the American spirit.

[portfire]

I'v seen this a while ago, it's bad practice simple as! Would you screen flash on that scale? It is the No1 rule NOT to screen flash right?

Dont forget that Potassium Perchlorate/Sulphur mixes are only slighty less sensitive than KClO3/S mixes

[Potassium chlorate]

They just screen the perchlorate and the sulfur. The aluminium is mixed in by hand afterwards.

And as for the stability of potassium perchlorate:

"The perchlorate ion is the least reactive oxidizer of the generalized chlorates. This is apparently paradoxical, since higher oxidation numbers are expected to be progressively stronger oxidizers, and less stable. Perchlorate does in fact have the highest redox potential and is least stable thermodynamically, but the central chlorine is a closed shell atom and well protected by the four oxygens. Hence, perchlorate reacts sluggishly. Most perchlorate compounds, especially salts of electropositive metals such as sodium perchlorate or potassium perchlorate, are slow to react unless heated."

Perchlorate

This is pretty simple chemistry.

[portfire]

They just screen the perchlorate and the sulfur. The aluminium is mixed in by hand afterwards.

Wrong!!! watch again

[seymour]

They just screen the perchlorate and the sulfur. The aluminium is mixed in by hand afterwards.

And as for the stability of potassium perchlorate:

"The perchlorate ion is the least reactive oxidizer of the generalized chlorates. This is apparently paradoxical, since higher oxidation numbers are expected to be progressively stronger oxidizers, and less stable. Perchlorate does in fact have the highest redox potential and is least stable thermodynamically, but the central chlorine is a closed shell atom and well protected by the four oxygens. Hence, perchlorate reacts sluggishly. Most perchlorate compounds, especially salts of electropositive metals such as sodium perchlorate or potassium perchlorate, are slow to react unless heated."

Perchlorate

This is pretty simple chemistry.

Yes, Potassium perchlorate is fairly stable compared to chlorates, and very stable compared to some other oxidisers (which are too dodgy to find firework use are they not?).

I also agree that many people do have an belief relating to some mixtures (including both perchlorate/sulfur and chlorate/sulfur) which exceedes the real danger. However this provides a margin of safety, and is not a bad thing. Aditionally, since devestatingly powerful flash powder using Potassium perchlorate and Aluminium can be made, which can perform every use that we have for flash powder, including breaking small crossettes, I believe the addition of Sulfur to the flash powders to add significant danger far beyond the reward.

I have no doubt that they have measures in place to make what they are doing safer, such as anti-static measures and pure chemicals, and the screen is probably not made of a dangerous material, but I would not be happy doing what they are doing. Professionals have bad practices and die too.