BJV Posted January 20, 2011 Posted January 20, 2011 Hi all, I have a couple of question. I had this pumpbuild several years ago and have never had a chanceto play with it yet.This Crossette pump is 1 3/4" ID.What would you recommend to brake them with?Could you give me a idea on the amount of lift,will be shooting them out of a 1 7/8" mortar. Would youuse 4fg or 2fg?Thanks,BJV http://barry.dcwisp.net/Crossette.jpg
pyrojig Posted January 22, 2011 Posted January 22, 2011 Hi all, I have a couple of question. I had this pumpbuild several years ago and have never had a chanceto play with it yet.This Crossette pump is 1 3/4" ID.What would you recommend to brake them with?Could you give me a idea on the amount of lift,will be shooting them out of a 1 7/8" mortar. Would youuse 4fg or 2fg?Thanks,BJV http://barry.dcwisp.net/Crossette.jpg I'd lift them with 3fa bp , and break them with a boosted black powder ( 70/30 flash). This is the best way I have seen it done, and it conserves on flash. The granulated bp is mixed with the flash, this creates a energetic filler that takes up space allowing your need for a large amount of flash to be reduced .
BJV Posted January 22, 2011 Author Posted January 22, 2011 I'd lift them with 3fa bp , and break them with a boosted black powder ( 70/30 flash). This is the best way I have seen it done, and it conserves on flash. The granulated bp is mixed with the flash, this creates a energetic filler that takes up space allowing your need for a large amount of flash to be reduced . Thanks for the information pyrojig.Can you be more specific on the ratio of BP to flash.Thanks again,BJV
Seymour Posted January 22, 2011 Posted January 22, 2011 Some trial end error is likely to be needed to tweak your crossette breaks to perfection. I'd suggest starting by filling the cavity to near the top with BP grain, and using flash to fill the spaces between grains + a little extra.
BJV Posted January 22, 2011 Author Posted January 22, 2011 Some trial end error is likely to be needed to tweak your crossette breaks to perfection. I'd suggest starting by filling the cavity to near the top with BP grain, and using flash to fill the spaces between grains + a little extra. Seymour thanks for information. That sounds like a good starting place.BJV
Seymour Posted January 22, 2011 Posted January 22, 2011 No problem. Note that I am referring to the standard 70/30 with Potassium perchlorate and Dark flake. If your flash is less hot you will need to use mote flash, and with some slow flash formulas, I'd suggest using pure flash and no BP to 'bulk it up'.
TrueBluePyro Posted January 23, 2011 Posted January 23, 2011 Also some people like to use granulated whistle because the flash distorts your eyes for a bit. Also some people like to use granulated whistle because the flash distorts your eyes for a bit.
Bonny Posted January 23, 2011 Posted January 23, 2011 As suggested, granulated whistle would be a good thing to try, as is BP/flash mix.I've only ever made 3/4" crossettes. I use a mix (approx. 50/50) of -20+40 BP and 70/30 flash. It seems to work well for me.
pyrojig Posted January 23, 2011 Posted January 23, 2011 @ truebluepyro I too agree that the flash can have that blinding effect, but it only shows on crossettes that have a low light output formula. I find that bright glitter to streamers can get away with the flash break, but the tiger tails and alike seem to be effected just for a moment. A 70/30 flash is the least bright of flash's compared to slow flash's. I like whistle as well , mainly for photography reasons. The 3/4 crossettes need a strong break, but the bigger one as described above will not. Id fill the crossette with bp almost to the top, and add flash to fill in the spaces between the granules maybe 1/2- 1g of flash. Id test in a gun and adjust break by flash %.
Bonny Posted January 23, 2011 Posted January 23, 2011 @ truebluepyro I too agree that the flash can have that blinding effect, but it only shows on crossettes that have a low light output formula. I find that bright glitter to streamers can get away with the flash break, but the tiger tails and alike seem to be effected just for a moment. A 70/30 flash is the least bright of flash's compared to slow flash's. I like whistle as well , mainly for photography reasons. The 3/4 crossettes need a strong break, but the bigger one as described above will not. Id fill the crossette with bp almost to the top, and add flash to fill in the spaces between the granules maybe 1/2- 1g of flash. Id test in a gun and adjust break by flash %. 1g of flash (+BP) seems like a lot for breaking a crossette. I've made salutes with very little confinement with 5g of flash... I think on larger crossettes granulated whistle would be the way to go, and only partly filling the cavity.
pyroguy1960 Posted January 23, 2011 Posted January 23, 2011 I recently made a bunch of 1.25 inch crosettes and broke them with 2fg/flash in about a 60/40 ratio. It was a little too strong, If I had it to do over I would have made the ratio more like 75 BP/25 Flash. I didn't see anyone answer your lift question in sporting/glazed BP terms as you asked. IMO 4FG is too fine to lift with, I would go with 2FG for lift. Here's the crossette shell again for reference, if you pay attention you can see that many were blown blind. 8inch_silvercrossette.wmv
pyrojig Posted January 23, 2011 Posted January 23, 2011 The lift suggested was 3fa....... I had a hard time picking out the blown blind stars. Only saw two possible spots on the lower side of the flower. This could be because of the angle your viewing the flower at. But only the shell maker knows exactly what his shell flower should look like.... I have shot shows that where good, but some of the shells had blind stars and missing spots in the rings etc, but the crowd never knew. I was bummed and they couldn't figure out why.. lol... pyrotechnitions can be perfectionist at times....
Mumbles Posted January 23, 2011 Posted January 23, 2011 The mix of flash and BP actually hides the light pretty well.
pyroguy1960 Posted January 23, 2011 Posted January 23, 2011 pyrotechnitions can be perfectionist at times.... Very true, every pyro is his/her own worst critic, my audience certainly didn't notice anything wrong with it. Overall I was pleased with that shell considering some of the shortcuts I took during it's construction.
BJV Posted January 23, 2011 Author Posted January 23, 2011 Hi All, I just want to thank everyone again for all the input.Below is a photo of a couple of crossettes I built this morning, each star weights 108grams. I think I will go with jms04081974 suggestion: 75BP/25Flash. It will be a few week before I will test them, but I will have video of them no matter the out come.Thanks.BJVhttp://barry.dcwisp.net/Stars.jpg
AdmiralDonSnider Posted January 23, 2011 Posted January 23, 2011 Anybody working with the old dark flash (KClO3-Sb2S3 etc.) formulas?
Mumbles Posted January 23, 2011 Posted January 23, 2011 I've been using the dark flash formulas. I know BJV is more than capable, but it's one of those things where you don't always feel comfortable recommending. Just a habit I suppose. I was trying to get it to work in a shotless arrangement, but never got 100% success. I've been working on converting to rolled shots. I think I know how to make them work shotless though.
pyroguy1960 Posted January 23, 2011 Posted January 23, 2011 BJV, just to ellaborate a little, I didn't fill them all the way to the top either. So just my 2 cents you should use 75/25 BP/Flash, but only fill them about 80% to the top. Not sure if anyone else has some suggestions on that, I do know that dark flash or shots is probably something I'll never get into, dark flash is a little more danger than I'm capable of working with at this point.
pyrojig Posted January 23, 2011 Posted January 23, 2011 Dark flash is very effective in minimal amounts. I'd just be concerned with the "mix" Bp/dark flash. Not that they arnt already quite sensitive, but one would have to consider the possibilities of "set-back" causing the bp to act like a grit it the dark flash, making it that much more sensitive . This could lead to a flower pot right off the bat. I have had great success with the dark flash as a pyrogen, and friction sensitive igniters, but am reluctant to use it in inserts or other items that experience set back . If 70/30 flash is the quoted safest in this area why deviate to a more sensitive mix?
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