823 replies to this topic

[Richard H]

I was thinking along those lines too. I might try an experiment to see if the smell is noticable.

[alany]

It is probably the fuse, I doubt many commercial crackers bother with the stick of blackmatch trick any more. It could also be a Barium Nitrate/Sulfur/Aluminium flash which is relatively cheap and quite powerful.

If in doubt you can always do some basic tests to reverse engineer the composition. Sulfur is probably most easily detected by warming with a little hydrochloric acid to release hydrogen sulfide. Traditionally lead acetate paper is used to detect the hydrogen sulfide but you can smell it quite clearly before your sense of smell for it gets tired.

Edited by alany, 18 March 2005 - 04:50 PM.

[Pretty green flames]

The sulphurous smell may have been due to the use of a sulphur based black match type fuse in the ground device.

Lancaster states that sometimes a piece of blackmatch (BP based) is inserted into the device to ensure flash ignition reliability.

there is indeed something BP based in the firecrackers but it is not blackmatch.
I took a few apart (still had some left from new year's eve ) it is just normal BP
with a little higher C content to make sure the user throws it out of his hand before it goes BANG

The PB is placed at the ignition cap which ignites the slowed down BP which then ignites the FP.

It's simple as that.

[Richard H]

An interesting 'safety' feature!

[alany]

Got a picture? It sounds more like priming.

[Pretty green flames]

I will try to cut 1 firecracker open and show you guys what it looks like

EDIT: Here's the pic

Edited by Pretty green flames, 18 March 2005 - 05:35 PM.

[Yugen-biki]

Shimizu writes that a BP prime is needed to get good ignition (and at the same time a good bang). This is more important when you make FP without sulfur like 70:30 KClO4:Al. Some sulfur in the KClO4&Al will not improve the bang very much. In fact, I find that a 60:40 mix of the chemiclas makes a better sound that 70:30 or the one with sulfur. But a BP brime (a small bag of BP) is needed to ignite it.

Any way, KClO4 based FP often have a BP prime to function properly.

[alany]

That looks like a match cracker to me, not a normal cracker with an external fuse?

Wonder how they get the bentonite in there?

[they say im crazy]

thanks for all the advice guys oh and how easily does a perc/al mix ignite?

[Pretty green flames]

It ignites VERY easily

[Pretty green flames]

That looks like a match cracker to me, not a normal cracker with an external fuse?

It is a match caracker, if i'm honest i havent seen any others.

Wonder how they get the bentonite in there?

First they ram the bentonite plug then put in the flash charge then BP and finaly they paste the strike match mix

[they say im crazy]

even with a single spark?

[Flashy]

even with a single spark?

With the tiniest spark you can imagine. Static from your self or from storing it in a plastic bag is enough to ignite it. It is scary stuff.

[alany]

First they ram the bentonite plug then put in the flash charge then BP and finaly they paste the strike match mix

Isn't that an air space between the flash and the fuse composition? I'd imagine the fuse would be pressed pretty well to make it reliable.

[Pretty green flames]

Isn't that an air space between the flash and the fuse composition?  I'd imagine the fuse would be pressed pretty well to make it reliable.

It's just some not cut craft paper, if i had cut that piece of craft the cracker would just fall apart and it would be difficult to show you guys what i'm talking about + i really didn't want to continue "teasing" the FP with a knife