823 replies to this topic

[gilbert pinkston]

yes thought about that during my post
maybe a 50% chance your correct

[NUKE]

Greetings
after about 16 months i decided to have a post here.


I have just make some black podwer and i have 200grams of aluminium podwer.I think it is

250mesh 5%
-250 mesh 95%
It says something like this.

I dont want to lose any hand so i would like to ask if these mix is same enough?

KNO3 50%
sulfur30%
20% aluminium.

I wont keep it for more than 2 days.
Is it very possible to ignite out of the blue?

I wont make more than 10 grams in a time.

[adamw]

KNO3 usually does not make good flash powder. There is a lot of Sulphur in there too. I suppose it would make a nice sliver streamer star!

[Phoenix]

5:3:2 flash works so long as it has very good confinement - in my experience (home made Al - nothing like real flash aluminium) it's actually slower burning than BP, but it is of course brighter. It shouldn't ignite spontaneously if it's kept dry. You could include a little boric acid to be on the safe side, but for short storage it's not essential. It can be hard to ignite, but black match or similar should do the trick.

It does indeed make very good streamer stars - I like to use it bound with a little shellac in alcohol to make 3mm cut cores for charcoal stars.

[NUKE]

Adamw you said that KNO3 doesn't make a good flash.I dont care very much for power but for the effect.

so as it isn't good flash it isn't so dangerous.Is it?

Sorry for my English

[adamw]

Since I have not really worked with KNO3 based flash (due to it's relative unsuitability), I cannot give full details of it's performance.

Still, I would not say it was totally safe as it presents a high burn risk since aluminium powder is still used.

[BigBang]

KNO3+Al flash is RELATIVELY speaking safe, in so much as it is fairly slow burning as far as flash goes, and fairly insensitive to shock and friction.

Having said that though, it does burn very hot and very bright, so as always, care must be exercised when using it.

[aapua]

Hello!
Haven't written a word for a sort of long time, but from last Friday I have something I think I inform You.

A close friend of mine and collegue from my previos company got very seriously injured when utilizing the remains of different types of explosive packets. He lost his left arm, finger from right hand, double broke his both legs and got serious wounds on chest and face. Not even talking the permanent psychical damage.

We used to work on military field, making different types of explosive packets for the army. Since the company is about to be closed, there was a special need for eliminating all the remains. Everything was OK with the small packets, and he left the big ones for the last. After successfully exploding 6 big ones, the 7th was a failure.

The packet contains 300 grams of pretty specific flash powder, which is more brisant but less powerful than the regular perc/al one. This flash we used has a very powerful influence to the close surrounding, serious influence does not exeed 3-5 charge diameters. The process looks like that: after removing the end disc the naked packet is easily possible to open by knife. He just pushed the knife through the pakcet, then pushed a safety fuze in and ignited it. The exploion occured when he just held the packet and looked down for the piece of fuze. Is not clear if something got in the packet with the knife or is it just an act of God, it just happened.

C'est la vie, the French say. Bad luck, may reply americans. I didn't write this for scaring you, what I'm saying is that even thousands of times tested mixtures can surprise you, and you bet not in a very pleasent ways.

Whatever you do, does not matter why you play with flashes, how big are the amounts and how careful you are, just think that you're not the only one in this world, there are always people around you who really love you and care about you. Don't hurt them. Think, before you do.

OK, that's it. Be cool and safety, safety, safety!

Aapua

[BigBang]

Yes i absolutely agree! It doesnt matter how many times youve made 'it', it can prematurely or spontaneously ignite. But as long as we take the necessary precautions, and wear the correct protective gear, we should be OK.

With this hobby comes an element of danger, whatever one does and however careful one is, we have to accept this, or else take up stamp collecting!!

[shadowpyro]

"Alany, as always, a perfect post with an excellent understanding of pyrotechnic chemistry.

Shadowpyro, may I ask why do you need a hybrid of Al and Mg? Many of the standard ratios for flash are more than 'fit for purpose'.

If your flash is not up 'to scratch' then maybe one should change the pre-cursors?"

sorry i havent replied for a while, i wasnt told that anyone had posted here...

Anyway, i decded to use a hybrid of aluminium and magnesium flash powder simply due to the fact that as my old aluminium powder of quite course and very hard to ignite, i decided ti mix it with magnesium to help it ignite better. I wasnt too keen on using magnesium flash powder on its own due to sensitivity problems- and its high cost comepared to Al.

thanks for the help on the ratios, but they were similar to the one i used at the start, either i think its be a good idea for me to improve my aluminium instead as i found out that magnesium/ aluminium hybrid flash powders have the disadvantages of boths metals etc. Myabe i'll leave this mix for sometime in the future to try...

[adamw]

aapua, that is very bad news - I hope he gets better.

When you say 'safety fuse' do you mean a visco (ie delay) fuse or an ignitor?

[aapua]

When you say 'safety fuse' do you mean a visco (ie delay) fuse or an ignitor?

Correct, the 1cm / sec delay fuze, burning only inside. No open flame.

[adamw]

Hmm.

It's not my place to say, but I'd use a remote electric firing system from a few hundred meters back

[aapua]

Hmm.

It's not my place to say, but I'd use a remote electric firing system from a few hundred meters back

It's something that I really don't understand - he should have done really this. When I was in the hospital, he wasn't quite OK to answer me. The packet itself was ready made, WITH electrical ignitor. All he had to do was to connect the wire and switch. I guess he must have opened this because he had that day several types that were just petards so the opening seemed the only way? Anyway, he did a huge mistake. I feel really sorry for that

[Pyromaster2003]

66% Ammonium Perchlorate/16% Ferro-Silicon/16% Wood Pulp/6% Oil

Could this be a possible louder flash powder composition just found it on the net, the text said it was a High Explosive but i don't think HE's can be made just by adding chemical powders together.

Don't think the link is relative to flash powder so i won't post it but just wondered if anyone has experience or knowledge with this explosive composition?