37 replies to this topic

[MDH]

My (limited) experience with greens suggests the most important thing is the oxidiser: mixtures that have barium nitrate and pot. perchlorate are always a bit pale compared
to those using barium chlorate or some AP oxidised mixtures.

Wouldn't potassium chlorate, barium nitrate, parlon and magnesium then make a generally good flame?

Does barium chlorate produce simply because of how pure the flame is without all of the other compounds present being burned up?

[portfire]

Just a quick question. Would either meal or greenmix work when firing Buell Red's out of shot tubes (for cakes). The stars will be rolled to 10mm and shot out of 15mm ID tubes. They will have some confinement, eg. tissue paper on top of the stars, and foil covering the tops of the tubes. I'm hoping meal will work, any thought's ?

Dean

[pyrotrev]

Does barium chlorate produce simply because of how pure the flame is without all of the other compounds present being burned up?

Precisely! Any other compounds in the flame will generate a "continuous" background emission spectrum which will to a greater or lesser extent mask the spectral lines (in this case green light) that we desire. Oh that strontium and barium perchlorate weren't so hygroscopic - life would be easy then.

Edited by pyrotrev, 01 June 2008 - 04:40 PM.

[pyrotrev]

Just a quick question. Would either meal or greenmix work when firing Buell Red's out of shot tubes (for cakes). The stars will be rolled to 10mm and shot out of 15mm ID tubes. They will have some confinement, eg. tissue paper on top of the stars, and foil covering the tops of the tubes. I'm hoping meal will work, any thought's ?

Dean

I'm not sure they would, though meal would likely be better than greenmix. You've got a fair amount of gap around your stars there so I would have thought a fast burning powder would be best. OK, good meal is quick, but when compressed (as will happen when you ram your tissue paper wads) it can burn more like a fountain than lift. If you can't be arsed with corning, maybe convert your meal to pulverone with a bit of gumarabic/water or red gum/alcohol?

[portfire]

Slight confusion, my fault My question was aimed at priming the stars for firing them out of shot tubes. I'm building a 120 shot Z cake and wanted to use Buell Red, and Veline Red, subing the SrCO3 for cryolite, so I get alternating red&yellow stars

[dr thrust]

hi dean, ive tried a meal+ 5% charcoal prime on my buell red cut stars, and observed that a thin coating of this prime just burned off not igniting the star, i found adding 5-8% 325# magnalium/dark pyro to the meal does the job but i also made it slightly thicker (3mm) something you may have a problem with because of the tolerances of your star to tube,

i didn't have any tolerances as such with then being rough stars in a shell maybe you could prime the end of the star with a thick bp/silicon/magnalium paste? is this for the meet? theres just never enough time for building/testing getting ever thing ready is there !!!

[pyrotrev]

Slight confusion, my fault My question was aimed at priming the stars for firing them out of shot tubes. I'm building a 120 shot Z cake and wanted to use Buell Red, and Veline Red, subing the SrCO3 for cryolite, so I get alternating red&yellow stars

No worries! I've never tried greenmix for priming, but I would guess it's likely to be inferior to meal with added metal powder or silicon, though possibly slightly better than straight meal since it tends to burn a bit drossy.

[cooperman435]

Personally I love using D1 glitter as a prime though I've been told:

50% meal
20% silicon
30% Kno3

is supposed to create large volumes of immensely hot slag which should ignite everything its set loose on.

[BrightStar]

50% meal
20% silicon
30% Kno3

7% Si in meal is usually quite enough. It easily sets fire to stars, trees, jeans, boots...

Been there, done that, still have the scorch marks

Edited by BrightStar, 02 June 2008 - 07:56 PM.

[cooperman435]

LOL safe rather than sorry though in all the senses

[portfire]

Thanks for the replies guys. It looks like Meal+silicon is a pretty effective prime then, I did want a simple prime, and it looks like I've got one lol.

[portfire]

Just an update. I can't seem to find silicon powder anywhere, so I'm using D1 Glitter for the Buell Reds and the Veline yellow, I'm told It will do the job.

On a side note, I've gone one step further with the stars. The effects will change 3 times, Chrys#6 to D1 to red or yellow, should look great, if the D1 ignites the color comp's....Any thoughts ?

[dr thrust]

cooperman's got kilo's of the stuff, i know ive just bought some!

[portfire]

cooperman's got kilo's of the stuff, i know ive just bought some!

DAM! Too late now, they've got 4mm of D1 rolled over them. Should be dry enough now for a stargun test later.

[cooperman435]

LOL have a look on the for sale page of my website its been there ages

Edited by cooperman435, 07 June 2008 - 02:54 PM.