823 replies to this topic

[aapua]

Basically saying there are 2 main reasons for self-ignition: static charge and impurities. (Of course, there are more reasons, like sudden shock or friction, but let's say that when you work carefully, these things don't happen).

2 ways to avoid static: you ground yourself and your equipment or use different chemicals. (As for your container - if you store your Al-powder in the original package, it should be OK, I guess the germans use a sort of anti-static plastic. But in most cases - avoid plastic if you can). There are many ways to ground yourself really well. But you must or at least should wear not only cotton gloves, but all your clothes.

A bit more challenging is to replace Al with some non-metal chemical. If the "bang" is all you need, there are no problems. But getting good flash is a bit tricky. From the point of safety - most of non-metal "bangpowders" are not so sensitive to static, and as for the detonation power I could say some of them could be AT LEAST as powerful as perc/al mixture. On the other hand, sometimes you may find that these mixtures are pretty sensitive to shock or friction. So again, first you should do a theoretical study.

But you can do something to avoid self-ignition caused by undesireable impurities. First - clean the place where you work, so nothing "extra" can't get in your mixture, second - spend a bit more money and buy only pure chemicals (I didn't mean of course some sort of analytically pure like say 99,999%, 99,5% is usually OK). "Pure" means that these extra elements and salts that are in the chemical, must be not dangerous to the mixture you make from it. Like - pot. perchlorate shall not contain chlorates, Al shall not include Mg and Fe2O3 (our company had a case like this one) etc.

There is not a thing like "bad luck" and things don't happen because "they just happen". Even chlorate and red phosphorus could be mixed and stored with success and no accidents. There was a suggestion to pack flash powder in the way that there will be no movement. The worst thing is when the loose powder is in the shell or tube or wherever really loose. Shaking and vibrating it cause particles to fly around in the space creating extra contact surface, as well as constant friction between particles. So, putting the FP into a paper bag and then into wherever would be another small step to minimize the danger.

Then you have to know about the critical points of humidity. It is forbidden to work with FP (actually with all loose powders) with low humidity, but close to 100% is also bad. Never overdry your powders and don't leave then to direct sunlight.

I'm sorry if it came out like don't, don't, don't. There is actually nothing new - I'm bloody sure you knew all this already. But I believe that repeating things like these, especially in such a dangerous field, woldn't be bad at all.

Good luck to you,

Aapua

[italteen3]

I'm sorry if it came out like don't, don't, don't. There is actually nothing new - I'm bloody sure you knew all this already. But I believe that repeating things like these, especially in such a dangerous field, woldn't be bad at all.

Good luck to you,

Aapua

I agree with you 110%. We have had new people on the forum who havent even mixed KNO3, C, and S, yet but have mixed tons of FP... Its definately good to repeat things, bring up new safety precautions, already proven methods, etc.

What is everyone's feeling on static guard?

[Yugen-biki]

It does not really matter if you and the other equipment is grounded as long as everything around you have the same electrical potential. As long as it has there whon't be any static disscharge. BUT if the FP were to come in contact with something else, a sparc may form. I allways ground myself and everything to the water pipes.

Welders glowes are good when handeling FP. Have all your tool on the woork bench, and no tools to small to be handeled with the glowes on.
The mixing of the Al and Perc. and filling and closing the containers are made with glowes on. (and all the rest of the protection equipment!).

[Draco_Americanus]

ha yeah you should block out arnichists cookbook however you may think i wouldn't touch that book with a 3 metere barge pole it's far too dangerous i wonder if anyone has actully made anything out of there and suvived!

by the grace of god I survived that evil book, I followed the info on making TNT and after one fire (batch got thrown out a window) and a second attempt it worked, very very stupid of Me to have done that but I was in high school then, The best thing that happened is my math teacher took the book away and I have not seen it since(about 12 years ago) If i had that book now, it would have been used in a thermite experment!

[Rhodri]

ALL!

Please can we not discuss this *particular* literature on the BPS forum.

The ACB has no home here and any such posts will be treated with the contempt they deserve.

[Draco_Americanus]

Shure thing!, but calling "it" literature may not be totalty accurate

[Richard H]

So you can't be arsed buying books then?

[Richard H]

Yes rather. I was under the impression you were talking about these copyrighted works.

[italteen3]

Back to FP.

I was brainstorming the other day, since Im not working on anything for a while, about new designs for cakes, quicker methods for projects, etc. when I was thinking about Flash. The method I use to load small aerial salutes involves folding a paper in half and pouring the FP out into the salute. My concern was if I had to make a powder scoop for faster neater loading would brass be the material of choice?

I dont like the pouring of FP as sometimes a "mini" avalanche of the powder can slightly over fill a tube or on my work bench. I clean everything up properly but its nerve wrecking when you are working with it and a scoop can help.

Any suggestions? Im making an order to Wolter soon for some custom tooling so another tool couldnt hurt.

[Yugen-biki]

I'm not sure Wolter deals with wood but a wooden spoon/scoop would be an alternative that is non electrostatic.