823 replies to this topic

[karlfoxman]

What? Why bring sulphur into the mixture? It makes it more sensetive than it already is!

[BigBang]

Yes quite right Karl, sulphur in flash is a definite no-no, completely unnecessary, just asking for trouble

If you are having trouble igniting 10micron ali powder, then you aint got 10micron ali powder!

This spec. ali powder is extremely reactive, and ignites extremely easily, mixed with most any oxidiser. You dont even need visco to light it, touch paper will do it. If it doesnt, you almost certainly havnt got 10 micron. Most probably a much coarser grade being sold as 10micron. Ive come across this many times.

Ive have a lot of different sizes from 1micron upwards, and to the naked eye, they all look the same, until you get to the quite coarse sizes.

Did you get it from a reputable supplier?.....im guessing not, coz a reputable supplier wouldnt sell this type of ali powder to an individual.

[s2525]

I would say it is due to shape,I am unsure of the safety aspect of this but did anyone here of ballmilling AL to make it flake??Of course you have to open container every few hours so it does not go pyrogrospic (or some word cant think how to spell it) Please note I am unsure of this I cannot even remember where i heard it so certainly dont try it!

[BigBang]

S25....it definitely is not due to the shape. Ali powder this fine is extremely reactive regardless of shape. Trust me on this one! Extreme care must be exercised when using ali powder this fine. Best to avoid using it altogether.

[shadowpyro]

Actually, when i did a few tests on ignitability of flash powders with availbale Al's, i found that 10micron Al flake (70/30 kclo4/Al) was hard enough with visco and required a bare black match to ignite it. Though once lit is rather impressive!-when i tried the same with spherical no effect I'd suggest not using spherical shaped Al, its very hard to light. Maybe use the sphrical stuff in stars, rocket tails or fountains?

[BigG]

Okay guys, this is becoming another flash discussion and we already have one of those so I’m going to merge forums.

A few notes:

1) You do not add sulfur to a flash mixture.
2) Beginner should NOT START WITH FLASH!!!!
3) Spherical shape does burn slower then flake, even in small size of 10 micron. Spherical can be used to make “dirty” flash – which burn slower – but flake is still a more reactive shape.

Please read before posting – I can already see repeat of subjects discussed many times before.

[Ritual33]

Amen to that

[Plays with Fire]

I'm just curious, what would happen if you took a standard flash and added a binder to make it into a homogeneous solid? Would it burn slower? Would it not matter?

[Ritual33]

Like a flare I think, depending on the composition.

Drew

[Creepin_pyro]

There are many types of star which are basically (relatively) slow flash compositions with a binder added, usually pressed very hard. An example would be Shimizu's 'Silver wave' compositions - these make a really beautiful white-tailed comet when consolidated, but when burnt as a loose powder, it is a 'slow' flash. Perfect for rising comets on shells, providing the shell has bright, metal-fuelled stars.

I think standard flash made into a comet would probably be extremely bright, fast burning, but would not leave a tail.

[adamw]

Plays with Fire: This is called SURFACE AREA!!!!

[Plays with Fire]

Plays with Fire: This is called SURFACE AREA!!!!

I am aware of what surface area is and how it affects burn rate. I also am aware that some really powerful non-pyro explosives detonate without being powdered; I don't think you need examples. Though I have been told conflicting things about whether flash detonates or deflaugrates, I was wondering if binding it would make a difference, and if having it fine enough before binding would have an effect on it's perfermance once bound.

[Rhodri]

Plays with fire - what exactly are you trying to do here? Are you interested in bright stars? Correct me if I'm wrong but it appears we're wandering away from pyro?

[Plays with Fire]

I AM NOT WANDERING ANYWHERE! ARGHHHHH! It was merely a question as to how flash works out of curiosity. NOTHING ELSE! My question was answered, so that's it, thank you.