Ramming black powder based compositions ?

[50AE]

Hi there,

 

One of my most prefered pyro devices are the fountains, so I ram many. All my compositions are based on a slow meal powder + some low sized particle metals or charcoal for spark effects.

But today I decided to read random things in the old APC forum, I enjoyed reading, till I stopped on the "Thugsta accident thread.

 

Apparently his accident occured while ramming a black powder rocket. The black powder ignited from a static charge. So I kinda freaked out and I'm affraid of ramming now. I don't know at what to believe? Some say that black powder is sensitive to static, other say it is a little, third guys say it's not sensitive at all.

 

I respect the ramming safety tips that I know. I ram with a wooden stick, small hammer, in cardboard tubes, putting low friction and impact sensitive mixtures. But Thugsta used the same tips, as I know from the old thread.

 

So this accident... Was it just a bad luck ? Because every day in the world, people are ramming at least 1000 BP rockets. Maybe he had an impurity in his powder that caused the accident ?

 

I'm glad Thugsta is doing well now.

[WarezWally]

BP is not static sensitive, I gave up trying to get it to ignite by passing a 10kV arc through it.

[mike_au]

I was reading the old forums a while back, wasn't he using metal tooling?

 

I don't think wood and cardboard could create static.

[InRainbows]

I was reading the old forums a while back, wasn't he using metal tooling?

 

I don't think wood and cardboard could create static.

A lot of people use metal tooling. It's what is made by most pyro suppliers, due to the fact that they last MUCH longer.

 

Now, I haven't read the thread where this is mentioned in detail, but, was it tooling he bought from, i.e. Wolter, or did he have it machined for him? If he did, maybe he didn't specify non-sparking metals for the tooling.

[Frozentech]

BP, with no sparking metals in it, has been rammed for literally centuries, with a low rate of accidents.

 

That said, I know of 3. Although a lot of people say BP is not static sensitive, I have found US Bureau of Mines studies from the 1930's that say it is. All the people who run an arc though it, miss one thing. They need to run that arc through the *dust cloud* that puffs up around the rammer when it's hit. I suspect that meal dust suspended in the air would be FAR more susceptible to static. I mean, flour and wheat chaff dust has exploded like that, and it's a little harder to light flour than BP usually ?

 

The other ( and I think more likely ) cause of accidents ramming BP comps, is that powder gets packed up inside the drift hole of the rammer, and is then violently compressed between the tip of the spindle and the bottom of the drift hole. Diesel effect, possibly ?

 

The other, is switching to a short rammer too early, and bottoming out , and again, "pinching" the comp.

 

I wear leather gloves and a lexan face shield when I ram BP rockets, just in case.

[50AE]

Well, thank you. So I should not worry much.

I don't get a diesel effect, because there are small spaces between the rammer and the tube, and the air comes out quickly. However, If I rush the rammer and don't press the composition gently first, meal powder comes out from these small spaces like a small dust cloud,. This "cloud" is sensitive to sparks, as you said, and maybe that was Thugsta's reason for the accident.

So I will avoid that.

[tentacles]

Most folks I know use granulated BP in their devices. It keeps the dust down big time. Just dampen regular meal (no binder) and rice through a screen.

[Aquarius]

Another tip is to dampen the mixture with a small percentage of water if dextrin bound or alcohol when bound with red gum.

Ricing the comp and using a liquid/solvent for a harder grain eliminates the dust problem ands keep the comp less active when wet, IF you have an accident.