bigbuck Posted August 26, 2016 Posted August 26, 2016 i am getting ready to roll willow diadem stars, do the roll quite easily or should they be pumped? also the formula I got does not give a suitable prime since they have a high percentage of charcoal will a simple bp prime do the trick? I have read many different opinions on bp for prime, does it need to contain a binder? I am assuming so to make it stick, I have ball milled both with and without dextrin, going to use 75/25 water/alc for solvent the formula is from bill Richardson
AzoMittle Posted August 26, 2016 Posted August 26, 2016 I'd be happy to help but could you please post the formula so we know what we're dealing with? Chances are they will roll fine. BP should work for prime, you could also add a small amount of aluminum or silicon or something to heat it up then a dusting of BP over top. Yes, the prime needs a binder.
bigbuck Posted August 26, 2016 Author Posted August 26, 2016 airfloat 39.1potassium nitrate 31.2sulfur 10.7dextrin or sgrs 7ferro ti med mesh 4.5ferro ti fine mesh 4.5titanium sponge medium mesh 3 sorry for all the questions but i think a dumb one is one i diddent ask and BTW thank you for the help azo
AzoMittle Posted August 26, 2016 Posted August 26, 2016 No problem, happy to help when I can. Straight BP is probably fine for that. I would still use a hotter prime if I could though since it's 12% metal, won't hurt it anyways. You can always try rolling up a handful with straight BP prime to test it.
AzoMittle Posted August 26, 2016 Posted August 26, 2016 Sure! Fencepost, pinball, monocapa, etc. any of those would work. They are hot enough to work for perchlorate colors so they should work for the diadem.
Mumbles Posted August 26, 2016 Posted August 26, 2016 The Pyrotechnic Compositions database section is for tried and tested formulas. It's being moved because of that.
DavidF Posted August 26, 2016 Posted August 26, 2016 I cut that formula in 750 gram batches, using the bag method. SGRS is the binder. They are primed while cutting with scratch mix. This gives stars that are about 3/8". This is them in a 4" shell:https://www.youtube.com/watch?v=2-M23z-VPzg 1
bigbuck Posted August 27, 2016 Author Posted August 27, 2016 wow those were very long hanging stars for only being 3/8 very nice!!! did you ball mill comp first?
DavidF Posted August 27, 2016 Posted August 27, 2016 Yes, I ball-milled the comp without the metals. I used red oak charcoal. I was looking to produce fire that was like rain. 9 of these shells at once worked pretty well to do it.
OldMarine Posted August 27, 2016 Posted August 27, 2016 Dave, did those burn to the ground? Hard to tell in the dark.
DavidF Posted August 27, 2016 Posted August 27, 2016 OldMarine, those ones did- just. But we did the rocket over a cliff on Lake Erie. That was my first successful batch after many stinkers it took to get it figured out. When I did my flight of them, I used a longer spindle for the rockets, and they burned out just above the ground. Here's the flight of them up close and personal. It was quite a thing to be under them https://www.youtube.com/watch?v=ZHOLPDTjliM 1
OldMarine Posted August 27, 2016 Posted August 27, 2016 Dave, would these be suited more to a long spindle BP rocket to get them on up there? I can get around 500ft from a nozzleless 3# rocket easily with a 4" heading
bigbuck Posted August 29, 2016 Author Posted August 29, 2016 i tried rolling willow diadem tonight and it seems with sgrs they take a bit more solvent to dampen them but only about 60% of my cores picked up comp, i am using 40-80 mesh titanium sponge and the stars do not seem to be picking up the coarser material, is this normal when star cores are small? or maybe I am doing something wrong????????, going to let small stars dry overnight and put second layer on tomorrow after work and see if as they get larger they will pick up coarser material, any suggestions?
NeighborJ Posted August 29, 2016 Posted August 29, 2016 (edited) Big buck I've had this same issue with the 40-80 mesh ti on other comps. I believe the comp I was rolling was milled too fine and would completely cover any wetness on the stars before the ti could stick. I was going to use coarser comp so this doesn't happen again but I haven't gotten around to it yet. Ive also had the idea to granulate my comp so it would have the same size as the ti. I'd also like to know if anyone else has ideas on this? Edited August 29, 2016 by NeighborJ
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