BP hulls coated with 2u dark alum

[Ipaced789]

Hi all,

 

Strange question that I cant find any insight on anywhere. Ive been making these mines using 37mm film canisters, using BP rice hulls as the lift. However, I decided to add a dash of aluminum to the hulls (just coated them while in the canister) and instead of the normal lift that I receive, I got an extremely violent report. Any ideas why? I was unaware that just aluminum powder and BP hulls would have this effect.

[Bourbon]

I have heard of this. To my understanding, you can spruce up BP with dark AL. If I remember right, 2% is just right for a bit of pep, before switching to a booster. As you increase the amount, it begins to retard the objective. Someone on one of the forums had a chart from some tests. Everything benificial ended at 6% if I remember correctly and that was considerate of your AL.

[Ipaced789]

Fascinating. Thats probably about what was used 0.2g on top of 15g of BP hulls. Thanks!

[Arthur]

Probably the equivalent of adding nitrate flash, but as you add more you run out of oxidiser.

[Richtee]

Probably the equivalent of adding nitrate flash, but as you add more you run out of oxidiser.

Interesting. Perhaps a solution for breaking smaller shells without making actual flash or benzo.

[Arthur]

Lots of commercial flashes are made with a BP like formulation with Al/S/KNO3

[Bourbon]

If...If, I remember correctly. They said they just sprinkled it in the BP while filling shells. They don't even bother mixing. I believe it was said, the Al moved about during the rest of the shell construction. (wrapping, pasting, spiking) I don't know that would ever try more then that 2%. It's just a trick for a snort anyway.

[kingkama]

In big insert shell commonly you will add some alluminium to rise pressure and heat for a wider break pattern, usually 2/3 BP hull 1/3 BP hull dusted in alluminium then sifted for remove excess dust. It works it's softer then flash, a bit stronger than bp, nice for enhancing the incendiary property and thermal output.

[dagabu]

A little dark aluminum in the burst also does not increase the visible light output on break like flash does.

[FlaMtnBkr]

I use to advise coating BP rice hulls or granules with just enough aluminum to dust them but not accumulate at the bottom and I know it's in the forums from a few years ago. It can strengthen BP burst without having to resort to whistle or flash. It can also be used with granulated whistle to make it hotter either as burst or a flash alternative.

 

BP salutes are normally deeper sounding but require lots of confinement. The aluminum really spices things up if you want a deeper report or to not deal with flash. Though a sprinkle of flash in the same manner helps even more.

 

Basically when the BP burns, it also burns the aluminum which burns first and before the center of the granules so is likely consumed before the shell/casing ruptures. But what it's doing is increasing the heat which increases the pressure, which in turn speeds up the burning rate of the BP, whistle, etc.

 

It's an easy trick to increase speed and strength of burst. Sometimes this is wanted, other times it is not. But it's handy to know without having to make faster BP or mess with more energetic compounds, assuming you're not asking too much of it.