6 replies to this topic

[dave]

the above have a burst of silver sparks, ~ 1/2 to 1 sec duration

 

any ideas on the composition ?

 

i was thinking gerb type, blackpowder with either titanium or aluminium but

looking at a you tube video they appear quite low on smoke, although it is difficult to tell on the video below

 

probably pressed with a hollow core down the middle

 

 

dave

[cooperman435]

It has to be NC with Ti surely?

[dave]

phil,

nitrocellulose did cross my mind for a smokeless effect,
are you suggesting an obturated device filled with loose
nc and titanium ?

I know ice fountains use a nitrocellulose fluff with mica

but the video certainly seems to suggest the slight crackle of titanium

dave

[portfire]

We happen to have these! 1/2" ID with a core through the grain, ignited at the bottom. Not sure whether they're NC based, I'll test! 

[cooperman435]

Ill place money that they will be and it may be MgAl if it crackles but Ti will crackle too I believe?

 

Id have expected exactly that Portfire, thin layer of comp with a core .

[dave]

We happen to have these! 1/2" ID with a core through the grain, ignited at the bottom. Not sure whether they're NC based, I'll test!

sounds like you are describing a weco 1.2sec stage gerb
if so its not nc based but looks like a b.p. mix

let me know if its nc

dave

[dave]

just found out they are

 

B.P. meal

Titanium

Talc

 

presume the talc is a processing aid / anti stick agent when pressing

(magnesium stearate may have been a better choice than talc)